Update to sqlite 3.7.17.

See for changes:
http://www.sqlite.org/releaselog/3_7_16.html
http://www.sqlite.org/releaselog/3_7_16_1.html
http://www.sqlite.org/releaselog/3_7_16_2.html
http://www.sqlite.org/releaselog/3_7_17.html

tested by sebastia@ on vax & sparc, by myself on
hppa/amd64/sparc64/sgi/i386/macppc.
looks ok to espie@

(a lot of kittens died during the preparation of this cvs import)

109 files changed, 13130 insertions, 1525 deletions

diff --git a/lib/libsqlite3/VERSION b/lib/libsqlite3/VERSION
index 305df923a39..9a4c4371ee7 100644
--- a/lib/libsqlite3/VERSION
+++ b/lib/libsqlite3/VERSION
@@ -1 +1 @@
-3.7.15.2
+3.7.17
diff --git a/lib/libsqlite3/ext/fts1/ft_hash.h b/lib/libsqlite3/ext/fts1/ft_hash.h
index 93b6dcfb48e..95871a4590c 100644
--- a/lib/libsqlite3/ext/fts1/ft_hash.h
+++ b/lib/libsqlite3/ext/fts1/ft_hash.h
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.  We've modified it slightly to serve as a standalone
 ** hash table implementation for the full-text indexing module.
 **
diff --git a/lib/libsqlite3/ext/fts1/fts1_hash.h b/lib/libsqlite3/ext/fts1/fts1_hash.h
index c31c430f7c0..9001152931c 100644
--- a/lib/libsqlite3/ext/fts1/fts1_hash.h
+++ b/lib/libsqlite3/ext/fts1/fts1_hash.h
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.  We've modified it slightly to serve as a standalone
 ** hash table implementation for the full-text indexing module.
 **
diff --git a/lib/libsqlite3/ext/fts2/fts2.c b/lib/libsqlite3/ext/fts2/fts2.c
index 93e03cd557d..f008ce6dc09 100644
--- a/lib/libsqlite3/ext/fts2/fts2.c
+++ b/lib/libsqlite3/ext/fts2/fts2.c
@@ -6779,7 +6779,7 @@ void sqlite3Fts2IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
 int sqlite3Fts2InitHashTable(sqlite3 *, fts2Hash *, const char *);
 
 /*
-** Initialise the fts2 extension. If this extension is built as part
+** Initialize the fts2 extension. If this extension is built as part
 ** of the sqlite library, then this function is called directly by
 ** SQLite. If fts2 is built as a dynamically loadable extension, this
 ** function is called by the sqlite3_extension_init() entry point.
@@ -6797,7 +6797,7 @@ int sqlite3Fts2Init(sqlite3 *db){
   sqlite3Fts2IcuTokenizerModule(&pIcu);
 #endif
 
-  /* Allocate and initialise the hash-table used to store tokenizers. */
+  /* Allocate and initialize the hash-table used to store tokenizers. */
   pHash = sqlite3_malloc(sizeof(fts2Hash));
   if( !pHash ){
     rc = SQLITE_NOMEM;
diff --git a/lib/libsqlite3/ext/fts2/fts2_hash.h b/lib/libsqlite3/ext/fts2/fts2_hash.h
index 571aa2c1c2a..02936f18bba 100644
--- a/lib/libsqlite3/ext/fts2/fts2_hash.h
+++ b/lib/libsqlite3/ext/fts2/fts2_hash.h
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.  We've modified it slightly to serve as a standalone
 ** hash table implementation for the full-text indexing module.
 **
diff --git a/lib/libsqlite3/ext/fts2/fts2_tokenizer.c b/lib/libsqlite3/ext/fts2/fts2_tokenizer.c
index f8b06633dac..a93790c8011 100644
--- a/lib/libsqlite3/ext/fts2/fts2_tokenizer.c
+++ b/lib/libsqlite3/ext/fts2/fts2_tokenizer.c
@@ -319,7 +319,7 @@ static void intTestFunc(
 /*
 ** Set up SQL objects in database db used to access the contents of
 ** the hash table pointed to by argument pHash. The hash table must
-** been initialised to use string keys, and to take a private copy 
+** been initialized to use string keys, and to take a private copy 
 ** of the key when a value is inserted. i.e. by a call similar to:
 **
 **    sqlite3Fts2HashInit(pHash, FTS2_HASH_STRING, 1);
diff --git a/lib/libsqlite3/ext/fts2/fts2_tokenizer.h b/lib/libsqlite3/ext/fts2/fts2_tokenizer.h
index 8c256b2bed3..8db2048d6bf 100644
--- a/lib/libsqlite3/ext/fts2/fts2_tokenizer.h
+++ b/lib/libsqlite3/ext/fts2/fts2_tokenizer.h
@@ -70,7 +70,7 @@ struct sqlite3_tokenizer_module {
   ** This method should return either SQLITE_OK (0), or an SQLite error 
   ** code. If SQLITE_OK is returned, then *ppTokenizer should be set
   ** to point at the newly created tokenizer structure. The generic
-  ** sqlite3_tokenizer.pModule variable should not be initialised by
+  ** sqlite3_tokenizer.pModule variable should not be initialized by
   ** this callback. The caller will do so.
   */
   int (*xCreate)(
diff --git a/lib/libsqlite3/ext/fts3/fts3.c b/lib/libsqlite3/ext/fts3/fts3.c
index 7a53ac37a34..c00a13f5a10 100644
--- a/lib/libsqlite3/ext/fts3/fts3.c
+++ b/lib/libsqlite3/ext/fts3/fts3.c
@@ -1571,7 +1571,7 @@ static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
       }else{
         rc = sqlite3_reset(pCsr->pStmt);
         if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
-          /* If no row was found and no error has occured, then the %_content
+          /* If no row was found and no error has occurred, then the %_content
           ** table is missing a row that is present in the full-text index.
           ** The data structures are corrupt.  */
           rc = FTS_CORRUPT_VTAB;
@@ -2811,7 +2811,7 @@ static void fts3SegReaderCursorFree(Fts3MultiSegReader *pSegcsr){
 }
 
 /*
-** This function retreives the doclist for the specified term (or term
+** This function retrieves the doclist for the specified term (or term
 ** prefix) from the database.
 */
 static int fts3TermSelect(
@@ -2975,14 +2975,12 @@ static int fts3FilterMethod(
     pCsr->iLangid = 0;
     if( nVal==2 ) pCsr->iLangid = sqlite3_value_int(apVal[1]);
 
+    assert( p->base.zErrMsg==0 );
     rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
-        p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr
+        p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr, 
+        &p->base.zErrMsg
     );
     if( rc!=SQLITE_OK ){
-      if( rc==SQLITE_ERROR ){
-        static const char *zErr = "malformed MATCH expression: [%s]";
-        p->base.zErrMsg = sqlite3_mprintf(zErr, zQuery);
-      }
       return rc;
     }
 
@@ -3562,7 +3560,7 @@ void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
 #endif
 
 /*
-** Initialise the fts3 extension. If this extension is built as part
+** Initialize the fts3 extension. If this extension is built as part
 ** of the sqlite library, then this function is called directly by
 ** SQLite. If fts3 is built as a dynamically loadable extension, this
 ** function is called by the sqlite3_extension_init() entry point.
@@ -3596,7 +3594,7 @@ int sqlite3Fts3Init(sqlite3 *db){
   sqlite3Fts3SimpleTokenizerModule(&pSimple);
   sqlite3Fts3PorterTokenizerModule(&pPorter);
 
-  /* Allocate and initialise the hash-table used to store tokenizers. */
+  /* Allocate and initialize the hash-table used to store tokenizers. */
   pHash = sqlite3_malloc(sizeof(Fts3Hash));
   if( !pHash ){
     rc = SQLITE_NOMEM;
@@ -3646,9 +3644,13 @@ int sqlite3Fts3Init(sqlite3 *db){
           db, "fts4", &fts3Module, (void *)pHash, 0
       );
     }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts3InitTok(db, (void *)pHash);
+    }
     return rc;
   }
 
+
   /* An error has occurred. Delete the hash table and return the error code. */
   assert( rc!=SQLITE_OK );
   if( pHash ){
@@ -5195,7 +5197,7 @@ int sqlite3Fts3EvalPhraseStats(
 ** of the current row. 
 **
 ** More specifically, the returned buffer contains 1 varint for each 
-** occurence of the phrase in the column, stored using the normal (delta+2) 
+** occurrence of the phrase in the column, stored using the normal (delta+2) 
 ** compression and is terminated by either an 0x01 or 0x00 byte. For example,
 ** if the requested column contains "a b X c d X X" and the position-list
 ** for 'X' is requested, the buffer returned may contain:
diff --git a/lib/libsqlite3/ext/fts3/fts3Int.h b/lib/libsqlite3/ext/fts3/fts3Int.h
index 77ca4704e80..b19064cd3ba 100644
--- a/lib/libsqlite3/ext/fts3/fts3Int.h
+++ b/lib/libsqlite3/ext/fts3/fts3Int.h
@@ -524,7 +524,7 @@ void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);
 
 /* fts3_expr.c */
 int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
-  char **, int, int, int, const char *, int, Fts3Expr **
+  char **, int, int, int, const char *, int, Fts3Expr **, char **
 );
 void sqlite3Fts3ExprFree(Fts3Expr *);
 #ifdef SQLITE_TEST
@@ -549,6 +549,9 @@ int sqlite3Fts3EvalPhrasePoslist(Fts3Cursor *, Fts3Expr *, int iCol, char **);
 int sqlite3Fts3MsrOvfl(Fts3Cursor *, Fts3MultiSegReader *, int *);
 int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr);
 
+/* fts3_tokenize_vtab.c */
+int sqlite3Fts3InitTok(sqlite3*, Fts3Hash *);
+
 /* fts3_unicode2.c (functions generated by parsing unicode text files) */
 #ifdef SQLITE_ENABLE_FTS4_UNICODE61
 int sqlite3FtsUnicodeFold(int, int);
diff --git a/lib/libsqlite3/ext/fts3/fts3_aux.c b/lib/libsqlite3/ext/fts3/fts3_aux.c
index a2bff2e1d35..9b582fcf8bf 100644
--- a/lib/libsqlite3/ext/fts3/fts3_aux.c
+++ b/lib/libsqlite3/ext/fts3/fts3_aux.c
@@ -70,17 +70,26 @@ static int fts3auxConnectMethod(
 
   UNUSED_PARAMETER(pUnused);
 
-  /* The user should specify a single argument - the name of an fts3 table. */
-  if( argc!=4 ){
-    *pzErr = sqlite3_mprintf(
-        "wrong number of arguments to fts4aux constructor"
-    );
-    return SQLITE_ERROR;
-  }
+  /* The user should invoke this in one of two forms:
+  **
+  **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table);
+  **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table-db, fts4-table);
+  */
+  if( argc!=4 && argc!=5 ) goto bad_args;
 
   zDb = argv[1]; 
   nDb = (int)strlen(zDb);
-  zFts3 = argv[3];
+  if( argc==5 ){
+    if( nDb==4 && 0==sqlite3_strnicmp("temp", zDb, 4) ){
+      zDb = argv[3]; 
+      nDb = (int)strlen(zDb);
+      zFts3 = argv[4];
+    }else{
+      goto bad_args;
+    }
+  }else{
+    zFts3 = argv[3];
+  }
   nFts3 = (int)strlen(zFts3);
 
   rc = sqlite3_declare_vtab(db, FTS3_TERMS_SCHEMA);
@@ -103,6 +112,10 @@ static int fts3auxConnectMethod(
 
   *ppVtab = (sqlite3_vtab *)p;
   return SQLITE_OK;
+
+ bad_args:
+  *pzErr = sqlite3_mprintf("invalid arguments to fts4aux constructor");
+  return SQLITE_ERROR;
 }
 
 /*
diff --git a/lib/libsqlite3/ext/fts3/fts3_expr.c b/lib/libsqlite3/ext/fts3/fts3_expr.c
index 7612789de58..c046d7d5ffc 100644
--- a/lib/libsqlite3/ext/fts3/fts3_expr.c
+++ b/lib/libsqlite3/ext/fts3/fts3_expr.c
@@ -106,7 +106,7 @@ struct ParseContext {
 ** This function is equivalent to the standard isspace() function. 
 **
 ** The standard isspace() can be awkward to use safely, because although it
-** is defined to accept an argument of type int, its behaviour when passed
+** is defined to accept an argument of type int, its behavior when passed
 ** an integer that falls outside of the range of the unsigned char type
 ** is undefined (and sometimes, "undefined" means segfault). This wrapper
 ** is defined to accept an argument of type char, and always returns 0 for
@@ -640,8 +640,10 @@ static int fts3ExprParse(
         }
         pNot->eType = FTSQUERY_NOT;
         pNot->pRight = p;
+        p->pParent = pNot;
         if( pNotBranch ){
           pNot->pLeft = pNotBranch;
+          pNotBranch->pParent = pNot;
         }
         pNotBranch = pNot;
         p = pPrev;
@@ -729,6 +731,7 @@ static int fts3ExprParse(
           pIter = pIter->pLeft;
         }
         pIter->pLeft = pRet;
+        pRet->pParent = pIter;
         pRet = pNotBranch;
       }
     }
@@ -746,30 +749,184 @@ exprparse_out:
 }
 
 /*
-** Parameters z and n contain a pointer to and length of a buffer containing
-** an fts3 query expression, respectively. This function attempts to parse the
-** query expression and create a tree of Fts3Expr structures representing the
-** parsed expression. If successful, *ppExpr is set to point to the head
-** of the parsed expression tree and SQLITE_OK is returned. If an error
-** occurs, either SQLITE_NOMEM (out-of-memory error) or SQLITE_ERROR (parse
-** error) is returned and *ppExpr is set to 0.
+** Return SQLITE_ERROR if the maximum depth of the expression tree passed 
+** as the only argument is more than nMaxDepth.
+*/
+static int fts3ExprCheckDepth(Fts3Expr *p, int nMaxDepth){
+  int rc = SQLITE_OK;
+  if( p ){
+    if( nMaxDepth<0 ){ 
+      rc = SQLITE_TOOBIG;
+    }else{
+      rc = fts3ExprCheckDepth(p->pLeft, nMaxDepth-1);
+      if( rc==SQLITE_OK ){
+        rc = fts3ExprCheckDepth(p->pRight, nMaxDepth-1);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** This function attempts to transform the expression tree at (*pp) to
+** an equivalent but more balanced form. The tree is modified in place.
+** If successful, SQLITE_OK is returned and (*pp) set to point to the 
+** new root expression node. 
 **
-** If parameter n is a negative number, then z is assumed to point to a
-** nul-terminated string and the length is determined using strlen().
+** nMaxDepth is the maximum allowable depth of the balanced sub-tree.
 **
-** The first parameter, pTokenizer, is passed the fts3 tokenizer module to
-** use to normalize query tokens while parsing the expression. The azCol[]
-** array, which is assumed to contain nCol entries, should contain the names
-** of each column in the target fts3 table, in order from left to right. 
-** Column names must be nul-terminated strings.
+** Otherwise, if an error occurs, an SQLite error code is returned and 
+** expression (*pp) freed.
+*/
+static int fts3ExprBalance(Fts3Expr **pp, int nMaxDepth){
+  int rc = SQLITE_OK;             /* Return code */
+  Fts3Expr *pRoot = *pp;          /* Initial root node */
+  Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */
+  int eType = pRoot->eType;       /* Type of node in this tree */
+
+  if( nMaxDepth==0 ){
+    rc = SQLITE_ERROR;
+  }
+
+  if( rc==SQLITE_OK && (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
+    Fts3Expr **apLeaf;
+    apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
+    if( 0==apLeaf ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
+    }
+
+    if( rc==SQLITE_OK ){
+      int i;
+      Fts3Expr *p;
+
+      /* Set $p to point to the left-most leaf in the tree of eType nodes. */
+      for(p=pRoot; p->eType==eType; p=p->pLeft){
+        assert( p->pParent==0 || p->pParent->pLeft==p );
+        assert( p->pLeft && p->pRight );
+      }
+
+      /* This loop runs once for each leaf in the tree of eType nodes. */
+      while( 1 ){
+        int iLvl;
+        Fts3Expr *pParent = p->pParent;     /* Current parent of p */
+
+        assert( pParent==0 || pParent->pLeft==p );
+        p->pParent = 0;
+        if( pParent ){
+          pParent->pLeft = 0;
+        }else{
+          pRoot = 0;
+        }
+        rc = fts3ExprBalance(&p, nMaxDepth-1);
+        if( rc!=SQLITE_OK ) break;
+
+        for(iLvl=0; p && iLvl<nMaxDepth; iLvl++){
+          if( apLeaf[iLvl]==0 ){
+            apLeaf[iLvl] = p;
+            p = 0;
+          }else{
+            assert( pFree );
+            pFree->pLeft = apLeaf[iLvl];
+            pFree->pRight = p;
+            pFree->pLeft->pParent = pFree;
+            pFree->pRight->pParent = pFree;
+
+            p = pFree;
+            pFree = pFree->pParent;
+            p->pParent = 0;
+            apLeaf[iLvl] = 0;
+          }
+        }
+        if( p ){
+          sqlite3Fts3ExprFree(p);
+          rc = SQLITE_TOOBIG;
+          break;
+        }
+
+        /* If that was the last leaf node, break out of the loop */
+        if( pParent==0 ) break;
+
+        /* Set $p to point to the next leaf in the tree of eType nodes */
+        for(p=pParent->pRight; p->eType==eType; p=p->pLeft);
+
+        /* Remove pParent from the original tree. */
+        assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );
+        pParent->pRight->pParent = pParent->pParent;
+        if( pParent->pParent ){
+          pParent->pParent->pLeft = pParent->pRight;
+        }else{
+          assert( pParent==pRoot );
+          pRoot = pParent->pRight;
+        }
+
+        /* Link pParent into the free node list. It will be used as an
+        ** internal node of the new tree.  */
+        pParent->pParent = pFree;
+        pFree = pParent;
+      }
+
+      if( rc==SQLITE_OK ){
+        p = 0;
+        for(i=0; i<nMaxDepth; i++){
+          if( apLeaf[i] ){
+            if( p==0 ){
+              p = apLeaf[i];
+              p->pParent = 0;
+            }else{
+              assert( pFree!=0 );
+              pFree->pRight = p;
+              pFree->pLeft = apLeaf[i];
+              pFree->pLeft->pParent = pFree;
+              pFree->pRight->pParent = pFree;
+
+              p = pFree;
+              pFree = pFree->pParent;
+              p->pParent = 0;
+            }
+          }
+        }
+        pRoot = p;
+      }else{
+        /* An error occurred. Delete the contents of the apLeaf[] array 
+        ** and pFree list. Everything else is cleaned up by the call to
+        ** sqlite3Fts3ExprFree(pRoot) below.  */
+        Fts3Expr *pDel;
+        for(i=0; i<nMaxDepth; i++){
+          sqlite3Fts3ExprFree(apLeaf[i]);
+        }
+        while( (pDel=pFree)!=0 ){
+          pFree = pDel->pParent;
+          sqlite3_free(pDel);
+        }
+      }
+
+      assert( pFree==0 );
+      sqlite3_free( apLeaf );
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3Fts3ExprFree(pRoot);
+    pRoot = 0;
+  }
+  *pp = pRoot;
+  return rc;
+}
+
+/*
+** This function is similar to sqlite3Fts3ExprParse(), with the following
+** differences:
 **
-** The iDefaultCol parameter should be passed the index of the table column
-** that appears on the left-hand-side of the MATCH operator (the default
-** column to match against for tokens for which a column name is not explicitly
-** specified as part of the query string), or -1 if tokens may by default
-** match any table column.
+**   1. It does not do expression rebalancing.
+**   2. It does not check that the expression does not exceed the 
+**      maximum allowable depth.
+**   3. Even if it fails, *ppExpr may still be set to point to an 
+**      expression tree. It should be deleted using sqlite3Fts3ExprFree()
+**      in this case.
 */
-int sqlite3Fts3ExprParse(
+static int fts3ExprParseUnbalanced(
   sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
   int iLangid,                        /* Language id for tokenizer */
   char **azCol,                       /* Array of column names for fts3 table */
@@ -798,28 +955,116 @@ int sqlite3Fts3ExprParse(
     n = (int)strlen(z);
   }
   rc = fts3ExprParse(&sParse, z, n, ppExpr, &nParsed);
+  assert( rc==SQLITE_OK || *ppExpr==0 );
 
   /* Check for mismatched parenthesis */
   if( rc==SQLITE_OK && sParse.nNest ){
     rc = SQLITE_ERROR;
+  }
+  
+  return rc;
+}
+
+/*
+** Parameters z and n contain a pointer to and length of a buffer containing
+** an fts3 query expression, respectively. This function attempts to parse the
+** query expression and create a tree of Fts3Expr structures representing the
+** parsed expression. If successful, *ppExpr is set to point to the head
+** of the parsed expression tree and SQLITE_OK is returned. If an error
+** occurs, either SQLITE_NOMEM (out-of-memory error) or SQLITE_ERROR (parse
+** error) is returned and *ppExpr is set to 0.
+**
+** If parameter n is a negative number, then z is assumed to point to a
+** nul-terminated string and the length is determined using strlen().
+**
+** The first parameter, pTokenizer, is passed the fts3 tokenizer module to
+** use to normalize query tokens while parsing the expression. The azCol[]
+** array, which is assumed to contain nCol entries, should contain the names
+** of each column in the target fts3 table, in order from left to right. 
+** Column names must be nul-terminated strings.
+**
+** The iDefaultCol parameter should be passed the index of the table column
+** that appears on the left-hand-side of the MATCH operator (the default
+** column to match against for tokens for which a column name is not explicitly
+** specified as part of the query string), or -1 if tokens may by default
+** match any table column.
+*/
+int sqlite3Fts3ExprParse(
+  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
+  int iLangid,                        /* Language id for tokenizer */
+  char **azCol,                       /* Array of column names for fts3 table */
+  int bFts4,                          /* True to allow FTS4-only syntax */
+  int nCol,                           /* Number of entries in azCol[] */
+  int iDefaultCol,                    /* Default column to query */
+  const char *z, int n,               /* Text of MATCH query */
+  Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */
+  char **pzErr                        /* OUT: Error message (sqlite3_malloc) */
+){
+  static const int MAX_EXPR_DEPTH = 12;
+  int rc = fts3ExprParseUnbalanced(
+      pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr
+  );
+  
+  /* Rebalance the expression. And check that its depth does not exceed
+  ** MAX_EXPR_DEPTH.  */
+  if( rc==SQLITE_OK && *ppExpr ){
+    rc = fts3ExprBalance(ppExpr, MAX_EXPR_DEPTH);
+    if( rc==SQLITE_OK ){
+      rc = fts3ExprCheckDepth(*ppExpr, MAX_EXPR_DEPTH);
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
     sqlite3Fts3ExprFree(*ppExpr);
     *ppExpr = 0;
+    if( rc==SQLITE_TOOBIG ){
+      *pzErr = sqlite3_mprintf(
+          "FTS expression tree is too large (maximum depth %d)", MAX_EXPR_DEPTH
+      );
+      rc = SQLITE_ERROR;
+    }else if( rc==SQLITE_ERROR ){
+      *pzErr = sqlite3_mprintf("malformed MATCH expression: [%s]", z);
+    }
   }
 
   return rc;
 }
 
 /*
+** Free a single node of an expression tree.
+*/
+static void fts3FreeExprNode(Fts3Expr *p){
+  assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );
+  sqlite3Fts3EvalPhraseCleanup(p->pPhrase);
+  sqlite3_free(p->aMI);
+  sqlite3_free(p);
+}
+
+/*
 ** Free a parsed fts3 query expression allocated by sqlite3Fts3ExprParse().
+**
+** This function would be simpler if it recursively called itself. But
+** that would mean passing a sufficiently large expression to ExprParse()
+** could cause a stack overflow.
 */
-void sqlite3Fts3ExprFree(Fts3Expr *p){
-  if( p ){
-    assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );
-    sqlite3Fts3ExprFree(p->pLeft);
-    sqlite3Fts3ExprFree(p->pRight);
-    sqlite3Fts3EvalPhraseCleanup(p->pPhrase);
-    sqlite3_free(p->aMI);
-    sqlite3_free(p);
+void sqlite3Fts3ExprFree(Fts3Expr *pDel){
+  Fts3Expr *p;
+  assert( pDel==0 || pDel->pParent==0 );
+  for(p=pDel; p && (p->pLeft||p->pRight); p=(p->pLeft ? p->pLeft : p->pRight)){
+    assert( p->pParent==0 || p==p->pParent->pRight || p==p->pParent->pLeft );
+  }
+  while( p ){
+    Fts3Expr *pParent = p->pParent;
+    fts3FreeExprNode(p);
+    if( pParent && p==pParent->pLeft && pParent->pRight ){
+      p = pParent->pRight;
+      while( p && (p->pLeft || p->pRight) ){
+        assert( p==p->pParent->pRight || p==p->pParent->pLeft );
+        p = (p->pLeft ? p->pLeft : p->pRight);
+      }
+    }else{
+      p = pParent;
+    }
   }
 }
 
@@ -871,6 +1116,9 @@ static int queryTestTokenizer(
 ** the returned expression text and then freed using sqlite3_free().
 */
 static char *exprToString(Fts3Expr *pExpr, char *zBuf){
+  if( pExpr==0 ){
+    return sqlite3_mprintf("");
+  }
   switch( pExpr->eType ){
     case FTSQUERY_PHRASE: {
       Fts3Phrase *pPhrase = pExpr->pPhrase;
@@ -978,10 +1226,21 @@ static void fts3ExprTest(
     azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);
   }
 
-  rc = sqlite3Fts3ExprParse(
-      pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
-  );
+  if( sqlite3_user_data(context) ){
+    char *zDummy = 0;
+    rc = sqlite3Fts3ExprParse(
+        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr, &zDummy
+    );
+    assert( rc==SQLITE_OK || pExpr==0 );
+    sqlite3_free(zDummy);
+  }else{
+    rc = fts3ExprParseUnbalanced(
+        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
+    );
+  }
+
   if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM ){
+    sqlite3Fts3ExprFree(pExpr);
     sqlite3_result_error(context, "Error parsing expression", -1);
   }else if( rc==SQLITE_NOMEM || !(zBuf = exprToString(pExpr, 0)) ){
     sqlite3_result_error_nomem(context);
@@ -1004,9 +1263,15 @@ exprtest_out:
 ** with database connection db. 
 */
 int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
-  return sqlite3_create_function(
+  int rc = sqlite3_create_function(
       db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
   );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "fts3_exprtest_rebalance", 
+        -1, SQLITE_UTF8, (void *)1, fts3ExprTest, 0, 0
+    );
+  }
+  return rc;
 }
 
 #endif
diff --git a/lib/libsqlite3/ext/fts3/fts3_hash.h b/lib/libsqlite3/ext/fts3/fts3_hash.h
index 399f51544ad..dc3fcf8334f 100644
--- a/lib/libsqlite3/ext/fts3/fts3_hash.h
+++ b/lib/libsqlite3/ext/fts3/fts3_hash.h
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.  We've modified it slightly to serve as a standalone
 ** hash table implementation for the full-text indexing module.
 **
diff --git a/lib/libsqlite3/ext/fts3/fts3_snippet.c b/lib/libsqlite3/ext/fts3/fts3_snippet.c
index 4bee014dcc4..d54a7875ea9 100644
--- a/lib/libsqlite3/ext/fts3/fts3_snippet.c
+++ b/lib/libsqlite3/ext/fts3/fts3_snippet.c
@@ -389,9 +389,9 @@ static int fts3SnippetFindPositions(Fts3Expr *pExpr, int iPhrase, void *ctx){
 ** is the snippet with the highest score, where scores are calculated
 ** by adding:
 **
-**   (a) +1 point for each occurence of a matchable phrase in the snippet.
+**   (a) +1 point for each occurrence of a matchable phrase in the snippet.
 **
-**   (b) +1000 points for the first occurence of each matchable phrase in 
+**   (b) +1000 points for the first occurrence of each matchable phrase in 
 **       the snippet for which the corresponding mCovered bit is not set.
 **
 ** The selected snippet parameters are stored in structure *pFragment before
diff --git a/lib/libsqlite3/ext/fts3/fts3_test.c b/lib/libsqlite3/ext/fts3/fts3_test.c
index 4da0b8f13d2..75ec6bd01d0 100644
--- a/lib/libsqlite3/ext/fts3/fts3_test.c
+++ b/lib/libsqlite3/ext/fts3/fts3_test.c
@@ -267,7 +267,7 @@ static int fts3_near_match_cmd(
 **
 ** Whether or not the arguments are present, this command returns a list of
 ** two integers - the initial chunksize and threshold when the command is
-** invoked. This can be used to restore the default behaviour after running
+** invoked. This can be used to restore the default behavior after running
 ** tests. For example:
 **
 **    # Override incr-load settings for testing:
diff --git a/lib/libsqlite3/ext/fts3/fts3_tokenize_vtab.c b/lib/libsqlite3/ext/fts3/fts3_tokenize_vtab.c
new file mode 100644
index 00000000000..364852ef82e
--- /dev/null
+++ b/lib/libsqlite3/ext/fts3/fts3_tokenize_vtab.c
@@ -0,0 +1,454 @@
+/*
+** 2013 Apr 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code for the "fts3tokenize" virtual table module.
+** An fts3tokenize virtual table is created as follows:
+**
+**   CREATE VIRTUAL TABLE <tbl> USING fts3tokenize(
+**       <tokenizer-name>, <arg-1>, ...
+**   );
+**
+** The table created has the following schema:
+**
+**   CREATE TABLE <tbl>(input, token, start, end, position)
+**
+** When queried, the query must include a WHERE clause of type:
+**
+**   input = <string>
+**
+** The virtual table module tokenizes this <string>, using the FTS3 
+** tokenizer specified by the arguments to the CREATE VIRTUAL TABLE 
+** statement and returns one row for each token in the result. With
+** fields set as follows:
+**
+**   input:   Always set to a copy of <string>
+**   token:   A token from the input.
+**   start:   Byte offset of the token within the input <string>.
+**   end:     Byte offset of the byte immediately following the end of the
+**            token within the input string.
+**   pos:     Token offset of token within input.
+**
+*/
+#include "fts3Int.h"
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+#include <string.h>
+#include <assert.h>
+
+typedef struct Fts3tokTable Fts3tokTable;
+typedef struct Fts3tokCursor Fts3tokCursor;
+
+/*
+** Virtual table structure.
+*/
+struct Fts3tokTable {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  const sqlite3_tokenizer_module *pMod;
+  sqlite3_tokenizer *pTok;
+};
+
+/*
+** Virtual table cursor structure.
+*/
+struct Fts3tokCursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  char *zInput;                   /* Input string */
+  sqlite3_tokenizer_cursor *pCsr; /* Cursor to iterate through zInput */
+  int iRowid;                     /* Current 'rowid' value */
+  const char *zToken;             /* Current 'token' value */
+  int nToken;                     /* Size of zToken in bytes */
+  int iStart;                     /* Current 'start' value */
+  int iEnd;                       /* Current 'end' value */
+  int iPos;                       /* Current 'pos' value */
+};
+
+/*
+** Query FTS for the tokenizer implementation named zName.
+*/
+static int fts3tokQueryTokenizer(
+  Fts3Hash *pHash,
+  const char *zName,
+  const sqlite3_tokenizer_module **pp,
+  char **pzErr
+){
+  sqlite3_tokenizer_module *p;
+  int nName = (int)strlen(zName);
+
+  p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
+  if( !p ){
+    *pzErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
+    return SQLITE_ERROR;
+  }
+
+  *pp = p;
+  return SQLITE_OK;
+}
+
+/*
+** The second argument, argv[], is an array of pointers to nul-terminated
+** strings. This function makes a copy of the array and strings into a 
+** single block of memory. It then dequotes any of the strings that appear
+** to be quoted.
+**
+** If successful, output parameter *pazDequote is set to point at the
+** array of dequoted strings and SQLITE_OK is returned. The caller is
+** responsible for eventually calling sqlite3_free() to free the array
+** in this case. Or, if an error occurs, an SQLite error code is returned.
+** The final value of *pazDequote is undefined in this case.
+*/
+static int fts3tokDequoteArray(
+  int argc,                       /* Number of elements in argv[] */
+  const char * const *argv,       /* Input array */
+  char ***pazDequote              /* Output array */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  if( argc==0 ){
+    *pazDequote = 0;
+  }else{
+    int i;
+    int nByte = 0;
+    char **azDequote;
+
+    for(i=0; i<argc; i++){
+      nByte += (int)(strlen(argv[i]) + 1);
+    }
+
+    *pazDequote = azDequote = sqlite3_malloc(sizeof(char *)*argc + nByte);
+    if( azDequote==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      char *pSpace = (char *)&azDequote[argc];
+      for(i=0; i<argc; i++){
+        int n = (int)strlen(argv[i]);
+        azDequote[i] = pSpace;
+        memcpy(pSpace, argv[i], n+1);
+        sqlite3Fts3Dequote(pSpace);
+        pSpace += (n+1);
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Schema of the tokenizer table.
+*/
+#define FTS3_TOK_SCHEMA "CREATE TABLE x(input, token, start, end, position)"
+
+/*
+** This function does all the work for both the xConnect and xCreate methods.
+** These tables have no persistent representation of their own, so xConnect
+** and xCreate are identical operations.
+**
+**   argv[0]: module name
+**   argv[1]: database name 
+**   argv[2]: table name
+**   argv[3]: first argument (tokenizer name)
+*/
+static int fts3tokConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pHash,                    /* Hash table of tokenizers */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  Fts3tokTable *pTab;
+  const sqlite3_tokenizer_module *pMod = 0;
+  sqlite3_tokenizer *pTok = 0;
+  int rc;
+  char **azDequote = 0;
+  int nDequote;
+
+  rc = sqlite3_declare_vtab(db, FTS3_TOK_SCHEMA);
+  if( rc!=SQLITE_OK ) return rc;
+
+  nDequote = argc-3;
+  rc = fts3tokDequoteArray(nDequote, &argv[3], &azDequote);
+
+  if( rc==SQLITE_OK ){
+    const char *zModule;
+    if( nDequote<1 ){
+      zModule = "simple";
+    }else{
+      zModule = azDequote[0];
+    }
+    rc = fts3tokQueryTokenizer((Fts3Hash*)pHash, zModule, &pMod, pzErr);
+  }
+
+  assert( (rc==SQLITE_OK)==(pMod!=0) );
+  if( rc==SQLITE_OK ){
+    const char * const *azArg = (const char * const *)&azDequote[1];
+    rc = pMod->xCreate((nDequote>1 ? nDequote-1 : 0), azArg, &pTok);
+  }
+
+  if( rc==SQLITE_OK ){
+    pTab = (Fts3tokTable *)sqlite3_malloc(sizeof(Fts3tokTable));
+    if( pTab==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    memset(pTab, 0, sizeof(Fts3tokTable));
+    pTab->pMod = pMod;
+    pTab->pTok = pTok;
+    *ppVtab = &pTab->base;
+  }else{
+    if( pTok ){
+      pMod->xDestroy(pTok);
+    }
+  }
+
+  sqlite3_free(azDequote);
+  return rc;
+}
+
+/*
+** This function does the work for both the xDisconnect and xDestroy methods.
+** These tables have no persistent representation of their own, so xDisconnect
+** and xDestroy are identical operations.
+*/
+static int fts3tokDisconnectMethod(sqlite3_vtab *pVtab){
+  Fts3tokTable *pTab = (Fts3tokTable *)pVtab;
+
+  pTab->pMod->xDestroy(pTab->pTok);
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/*
+** xBestIndex - Analyze a WHERE and ORDER BY clause.
+*/
+static int fts3tokBestIndexMethod(
+  sqlite3_vtab *pVTab, 
+  sqlite3_index_info *pInfo
+){
+  int i;
+  UNUSED_PARAMETER(pVTab);
+
+  for(i=0; i<pInfo->nConstraint; i++){
+    if( pInfo->aConstraint[i].usable 
+     && pInfo->aConstraint[i].iColumn==0 
+     && pInfo->aConstraint[i].op==SQLITE_INDEX_CONSTRAINT_EQ 
+    ){
+      pInfo->idxNum = 1;
+      pInfo->aConstraintUsage[i].argvIndex = 1;
+      pInfo->aConstraintUsage[i].omit = 1;
+      pInfo->estimatedCost = 1;
+      return SQLITE_OK;
+    }
+  }
+
+  pInfo->idxNum = 0;
+  assert( pInfo->estimatedCost>1000000.0 );
+
+  return SQLITE_OK;
+}
+
+/*
+** xOpen - Open a cursor.
+*/
+static int fts3tokOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  Fts3tokCursor *pCsr;
+  UNUSED_PARAMETER(pVTab);
+
+  pCsr = (Fts3tokCursor *)sqlite3_malloc(sizeof(Fts3tokCursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(Fts3tokCursor));
+
+  *ppCsr = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+/*
+** Reset the tokenizer cursor passed as the only argument. As if it had
+** just been returned by fts3tokOpenMethod().
+*/
+static void fts3tokResetCursor(Fts3tokCursor *pCsr){
+  if( pCsr->pCsr ){
+    Fts3tokTable *pTab = (Fts3tokTable *)(pCsr->base.pVtab);
+    pTab->pMod->xClose(pCsr->pCsr);
+    pCsr->pCsr = 0;
+  }
+  sqlite3_free(pCsr->zInput);
+  pCsr->zInput = 0;
+  pCsr->zToken = 0;
+  pCsr->nToken = 0;
+  pCsr->iStart = 0;
+  pCsr->iEnd = 0;
+  pCsr->iPos = 0;
+  pCsr->iRowid = 0;
+}
+
+/*
+** xClose - Close a cursor.
+*/
+static int fts3tokCloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+
+  fts3tokResetCursor(pCsr);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** xNext - Advance the cursor to the next row, if any.
+*/
+static int fts3tokNextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
+  int rc;                         /* Return code */
+
+  pCsr->iRowid++;
+  rc = pTab->pMod->xNext(pCsr->pCsr,
+      &pCsr->zToken, &pCsr->nToken,
+      &pCsr->iStart, &pCsr->iEnd, &pCsr->iPos
+  );
+
+  if( rc!=SQLITE_OK ){
+    fts3tokResetCursor(pCsr);
+    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  }
+
+  return rc;
+}
+
+/*
+** xFilter - Initialize a cursor to point at the start of its data.
+*/
+static int fts3tokFilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *idxStr,             /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  int rc = SQLITE_ERROR;
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
+  UNUSED_PARAMETER(idxStr);
+  UNUSED_PARAMETER(nVal);
+
+  fts3tokResetCursor(pCsr);
+  if( idxNum==1 ){
+    const char *zByte = (const char *)sqlite3_value_text(apVal[0]);
+    int nByte = sqlite3_value_bytes(apVal[0]);
+    pCsr->zInput = sqlite3_malloc(nByte+1);
+    if( pCsr->zInput==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memcpy(pCsr->zInput, zByte, nByte);
+      pCsr->zInput[nByte] = 0;
+      rc = pTab->pMod->xOpen(pTab->pTok, pCsr->zInput, nByte, &pCsr->pCsr);
+      if( rc==SQLITE_OK ){
+        pCsr->pCsr->pTokenizer = pTab->pTok;
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK ) return rc;
+  return fts3tokNextMethod(pCursor);
+}
+
+/*
+** xEof - Return true if the cursor is at EOF, or false otherwise.
+*/
+static int fts3tokEofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  return (pCsr->zToken==0);
+}
+
+/*
+** xColumn - Return a column value.
+*/
+static int fts3tokColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+
+  /* CREATE TABLE x(input, token, start, end, position) */
+  switch( iCol ){
+    case 0:
+      sqlite3_result_text(pCtx, pCsr->zInput, -1, SQLITE_TRANSIENT);
+      break;
+    case 1:
+      sqlite3_result_text(pCtx, pCsr->zToken, pCsr->nToken, SQLITE_TRANSIENT);
+      break;
+    case 2:
+      sqlite3_result_int(pCtx, pCsr->iStart);
+      break;
+    case 3:
+      sqlite3_result_int(pCtx, pCsr->iEnd);
+      break;
+    default:
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, pCsr->iPos);
+      break;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** xRowid - Return the current rowid for the cursor.
+*/
+static int fts3tokRowidMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite_int64 *pRowid            /* OUT: Rowid value */
+){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  *pRowid = (sqlite3_int64)pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** Register the fts3tok module with database connection db. Return SQLITE_OK
+** if successful or an error code if sqlite3_create_module() fails.
+*/
+int sqlite3Fts3InitTok(sqlite3 *db, Fts3Hash *pHash){
+  static const sqlite3_module fts3tok_module = {
+     0,                           /* iVersion      */
+     fts3tokConnectMethod,        /* xCreate       */
+     fts3tokConnectMethod,        /* xConnect      */
+     fts3tokBestIndexMethod,      /* xBestIndex    */
+     fts3tokDisconnectMethod,     /* xDisconnect   */
+     fts3tokDisconnectMethod,     /* xDestroy      */
+     fts3tokOpenMethod,           /* xOpen         */
+     fts3tokCloseMethod,          /* xClose        */
+     fts3tokFilterMethod,         /* xFilter       */
+     fts3tokNextMethod,           /* xNext         */
+     fts3tokEofMethod,            /* xEof          */
+     fts3tokColumnMethod,         /* xColumn       */
+     fts3tokRowidMethod,          /* xRowid        */
+     0,                           /* xUpdate       */
+     0,                           /* xBegin        */
+     0,                           /* xSync         */
+     0,                           /* xCommit       */
+     0,                           /* xRollback     */
+     0,                           /* xFindFunction */
+     0,                           /* xRename       */
+     0,                           /* xSavepoint    */
+     0,                           /* xRelease      */
+     0                            /* xRollbackTo   */
+  };
+  int rc;                         /* Return code */
+
+  rc = sqlite3_create_module(db, "fts3tokenize", &fts3tok_module, (void*)pHash);
+  return rc;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
diff --git a/lib/libsqlite3/ext/fts3/fts3_tokenizer.c b/lib/libsqlite3/ext/fts3/fts3_tokenizer.c
index 8241be81fc2..04f84460e87 100644
--- a/lib/libsqlite3/ext/fts3/fts3_tokenizer.c
+++ b/lib/libsqlite3/ext/fts3/fts3_tokenizer.c
@@ -428,7 +428,7 @@ static void intTestFunc(
 /*
 ** Set up SQL objects in database db used to access the contents of
 ** the hash table pointed to by argument pHash. The hash table must
-** been initialised to use string keys, and to take a private copy 
+** been initialized to use string keys, and to take a private copy 
 ** of the key when a value is inserted. i.e. by a call similar to:
 **
 **    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
diff --git a/lib/libsqlite3/ext/fts3/fts3_tokenizer.h b/lib/libsqlite3/ext/fts3/fts3_tokenizer.h
index c91c7ed7904..4a40b2b3850 100644
--- a/lib/libsqlite3/ext/fts3/fts3_tokenizer.h
+++ b/lib/libsqlite3/ext/fts3/fts3_tokenizer.h
@@ -70,7 +70,7 @@ struct sqlite3_tokenizer_module {
   ** This method should return either SQLITE_OK (0), or an SQLite error 
   ** code. If SQLITE_OK is returned, then *ppTokenizer should be set
   ** to point at the newly created tokenizer structure. The generic
-  ** sqlite3_tokenizer.pModule variable should not be initialised by
+  ** sqlite3_tokenizer.pModule variable should not be initialized by
   ** this callback. The caller will do so.
   */
   int (*xCreate)(
diff --git a/lib/libsqlite3/ext/fts3/fts3_unicode.c b/lib/libsqlite3/ext/fts3/fts3_unicode.c
index 79941edbb82..188358eade4 100644
--- a/lib/libsqlite3/ext/fts3/fts3_unicode.c
+++ b/lib/libsqlite3/ext/fts3/fts3_unicode.c
@@ -125,7 +125,7 @@ static int unicodeDestroy(sqlite3_tokenizer *pTokenizer){
 **
 ** If a standalone diacritic mark (one that sqlite3FtsUnicodeIsdiacritic()
 ** identifies as a diacritic) occurs in the zIn/nIn string it is ignored.
-** It is not possible to change the behaviour of the tokenizer with respect
+** It is not possible to change the behavior of the tokenizer with respect
 ** to these codepoints.
 */
 static int unicodeAddExceptions(
diff --git a/lib/libsqlite3/ext/fts3/fts3_write.c b/lib/libsqlite3/ext/fts3/fts3_write.c
index bda7fbbe1a9..269d1dd5993 100644
--- a/lib/libsqlite3/ext/fts3/fts3_write.c
+++ b/lib/libsqlite3/ext/fts3/fts3_write.c
@@ -1482,6 +1482,7 @@ static int fts3SegReaderNextDocid(
       *pnOffsetList = (int)(p - pReader->pOffsetList - 1);
     }
 
+    /* List may have been edited in place by fts3EvalNearTrim() */
     while( p<pEnd && *p==0 ) p++;
   
     /* If there are no more entries in the doclist, set pOffsetList to
@@ -2497,9 +2498,13 @@ static int fts3DeleteSegdir(
 **
 ** If there are no entries in the input position list for column iCol, then
 ** *pnList is set to zero before returning.
+**
+** If parameter bZero is non-zero, then any part of the input list following
+** the end of the output list is zeroed before returning.
 */
 static void fts3ColumnFilter(
   int iCol,                       /* Column to filter on */
+  int bZero,                      /* Zero out anything following *ppList */
   char **ppList,                  /* IN/OUT: Pointer to position list */
   int *pnList                     /* IN/OUT: Size of buffer *ppList in bytes */
 ){
@@ -2528,6 +2533,9 @@ static void fts3ColumnFilter(
     p += sqlite3Fts3GetVarint32(p, &iCurrent);
   }
 
+  if( bZero && &pList[nList]!=pEnd ){
+    memset(&pList[nList], 0, pEnd - &pList[nList]);
+  }
   *ppList = pList;
   *pnList = nList;
 }
@@ -2601,19 +2609,19 @@ int sqlite3Fts3MsrIncrNext(
       if( rc!=SQLITE_OK ) return rc;
       fts3SegReaderSort(pMsr->apSegment, nMerge, j, xCmp);
 
+      if( nList>0 && fts3SegReaderIsPending(apSegment[0]) ){
+        rc = fts3MsrBufferData(pMsr, pList, nList+1);
+        if( rc!=SQLITE_OK ) return rc;
+        assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 );
+        pList = pMsr->aBuffer;
+      }
+
       if( pMsr->iColFilter>=0 ){
-        fts3ColumnFilter(pMsr->iColFilter, &pList, &nList);
+        fts3ColumnFilter(pMsr->iColFilter, 1, &pList, &nList);
       }
 
       if( nList>0 ){
-        if( fts3SegReaderIsPending(apSegment[0]) ){
-          rc = fts3MsrBufferData(pMsr, pList, nList+1);
-          if( rc!=SQLITE_OK ) return rc;
-          *paPoslist = pMsr->aBuffer;
-          assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 );
-        }else{
-          *paPoslist = pList;
-        }
+        *paPoslist = pList;
         *piDocid = iDocid;
         *pnPoslist = nList;
         break;
@@ -2856,7 +2864,7 @@ int sqlite3Fts3SegReaderStep(
         }
 
         if( isColFilter ){
-          fts3ColumnFilter(pFilter->iCol, &pList, &nList);
+          fts3ColumnFilter(pFilter->iCol, 0, &pList, &nList);
         }
 
         if( !isIgnoreEmpty || nList>0 ){
diff --git a/lib/libsqlite3/ext/icu/README.txt b/lib/libsqlite3/ext/icu/README.txt
index c5cadb57d1f..d744f74981d 100644
--- a/lib/libsqlite3/ext/icu/README.txt
+++ b/lib/libsqlite3/ext/icu/README.txt
@@ -98,7 +98,7 @@ SQLite. Documentation follows.
         <string> REGEXP <re-pattern>
 
     This extension uses the ICU defaults for regular expression matching
-    behaviour. Specifically, this means that:
+    behavior. Specifically, this means that:
 
         * Matching is case-sensitive,
         * Regular expression comments are not allowed within patterns, and
diff --git a/lib/libsqlite3/ext/misc/amatch.c b/lib/libsqlite3/ext/misc/amatch.c
new file mode 100644
index 00000000000..b61308054ec
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/amatch.c
@@ -0,0 +1,1483 @@
+/*
+** 2013-03-14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code for a demonstration virtual table that finds
+** "approximate matches" - strings from a finite set that are nearly the
+** same as a single input string.  The virtual table is called "amatch".
+**
+** A amatch virtual table is created like this:
+**
+**     CREATE VIRTUAL TABLE f USING approximate_match(
+**        vocabulary_table=<tablename>,      -- V
+**        vocabulary_word=<columnname>,      -- W
+**        vocabulary_language=<columnname>,  -- L
+**        edit_distances=<edit-cost-table>
+**     );
+**
+** When it is created, the new amatch table must be supplied with the
+** the name of a table V and columns V.W and V.L such that 
+**
+**     SELECT W FROM V WHERE L=$language
+**
+** returns the allowed vocabulary for the match.  If the "vocabulary_language"
+** or L columnname is left unspecified or is an empty string, then no
+** filtering of the vocabulary by language is performed. 
+**
+** For efficiency, it is essential that the vocabulary table be indexed:
+**
+**     CREATE vocab_index ON V(W)
+**
+** A separate edit-cost-table provides scoring information that defines 
+** what it means for one string to be "close" to another.
+**
+** The edit-cost-table must contain exactly four columns (more precisely,
+** the statement "SELECT * FROM <edit-cost-table>" must return records
+** that consist of four columns). It does not matter what the columns are
+** named. 
+**
+** Each row in the edit-cost-table represents a single character
+** transformation going from user input to the vocabulary. The leftmost 
+** column of the row (column 0) contains an integer identifier of the
+** language to which the transformation rule belongs (see "MULTIPLE LANGUAGES"
+** below). The second column of the row (column 1) contains the input
+** character or characters - the characters of user input. The third 
+** column contains characters as they appear in the vocabulary table.
+** And the fourth column contains the integer cost of making the
+** transformation. For example:
+**
+**    CREATE TABLE f_data(iLang, cFrom, cTo, Cost);
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '', 'a', 100);
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, 'b', '', 87);
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, 'o', 'oe', 38);
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, 'oe', 'o', 40);
+**
+** The first row inserted into the edit-cost-table by the SQL script
+** above indicates that the cost of having an extra 'a' in the vocabulary
+** table that is missing in the user input 100.  (All costs are integers.
+** Overall cost must not exceed 16777216.)  The second INSERT statement 
+** creates a rule saying that the cost of having a single letter 'b' in
+** user input which is missing in the vocabulary table is 87.  The third
+** INSERT statement mean that the cost of matching an 'o' in user input 
+** against an 'oe' in the vocabulary table is 38.  And so forth.
+**
+** The following rules are special:
+**
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '?', '', 97);
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '', '?', 98);
+**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '?', '?', 99);
+**
+** The '?' to '' rule is the cost of having any single character in the input
+** that is not found in the vocabular.  The '' to '?' rule is the cost of
+** having a character in the vocabulary table that is missing from input.
+** And the '?' to '?' rule is the cost of doing an arbitrary character
+** substitution.  These three generic rules apply across all languages.
+** In other words, the iLang field is ignored for the generic substitution
+** rules.  If more than one cost is given for a generic substitution rule,
+** then the lowest cost is used.
+**
+** Once it has been created, the amatch virtual table can be queried
+** as follows:
+**
+**    SELECT word, distance FROM f
+**     WHERE word MATCH 'abcdefg'
+**       AND distance<200;
+**
+** This query outputs the strings contained in the T(F) field that
+** are close to "abcdefg" and in order of increasing distance.  No string
+** is output more than once.  If there are multiple ways to transform the
+** target string ("abcdefg") into a string in the vocabulary table then
+** the lowest cost transform is the one that is returned.  In this example,
+** the search is limited to strings with a total distance of less than 200.
+**
+** For efficiency, it is important to put tight bounds on the distance.
+** The time and memory space needed to perform this query is exponential
+** in the maximum distance.  A good rule of thumb is to limit the distance
+** to no more than 1.5 or 2 times the maximum cost of any rule in the
+** edit-cost-table.
+**
+** The amatch is a read-only table.  Any attempt to DELETE, INSERT, or
+** UPDATE on a amatch table will throw an error.
+**
+** It is important to put some kind of a limit on the amatch output.  This
+** can be either in the form of a LIMIT clause at the end of the query,
+** or better, a "distance<NNN" constraint where NNN is some number.  The
+** running time and memory requirement is exponential in the value of NNN 
+** so you want to make sure that NNN is not too big.  A value of NNN that
+** is about twice the average transformation cost seems to give good results.
+**
+** The amatch table can be useful for tasks such as spelling correction.
+** Suppose all allowed words are in table vocabulary(w).  Then one would create
+** an amatch virtual table like this:
+**
+**   CREATE VIRTUAL TABLE ex1 USING amatch(
+**       vocabtable=vocabulary,
+**       vocabcolumn=w,
+**       edit_distances=ec1
+**   );
+**
+** Then given an input word $word, look up close spellings this way:
+**
+**   SELECT word, distance FROM ex1
+**    WHERE word MATCH $word AND distance<200;
+**
+** MULTIPLE LANGUAGES
+**
+** Normally, the "iLang" value associated with all character transformations
+** in the edit-cost-table is zero. However, if required, the amatch 
+** virtual table allows multiple languages to be defined. Each query uses 
+** only a single iLang value.   This allows, for example, a single 
+** amatch table to support multiple languages.
+**
+** By default, only the rules with iLang=0 are used. To specify an 
+** alternative language, a "language = ?" expression must be added to the
+** WHERE clause of a SELECT, where ? is the integer identifier of the desired 
+** language. For example:
+**
+**   SELECT word, distance FROM ex1
+**    WHERE word MATCH $word
+**      AND distance<=200
+**      AND language=1 -- Specify use language 1 instead of 0
+**
+** If no "language = ?" constraint is specified in the WHERE clause, language
+** 0 is used.
+**
+** LIMITS
+**
+** The maximum language number is 2147483647.  The maximum length of either
+** of the strings in the second or third column of the amatch data table
+** is 50 bytes.  The maximum cost on a rule is 1000.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Forward declaration of objects used by this implementation
+*/
+typedef struct amatch_vtab amatch_vtab;
+typedef struct amatch_cursor amatch_cursor;
+typedef struct amatch_rule amatch_rule;
+typedef struct amatch_word amatch_word;
+typedef struct amatch_avl amatch_avl;
+
+
+/*****************************************************************************
+** AVL Tree implementation
+*/
+/*
+** Objects that want to be members of the AVL tree should embedded an
+** instance of this structure.
+*/
+struct amatch_avl {
+  amatch_word *pWord;   /* Points to the object being stored in the tree */
+  char *zKey;           /* Key.  zero-terminated string.  Must be unique */
+  amatch_avl *pBefore;  /* Other elements less than zKey */
+  amatch_avl *pAfter;   /* Other elements greater than zKey */
+  amatch_avl *pUp;      /* Parent element */
+  short int height;     /* Height of this node.  Leaf==1 */
+  short int imbalance;  /* Height difference between pBefore and pAfter */
+};
+
+/* Recompute the amatch_avl.height and amatch_avl.imbalance fields for p.
+** Assume that the children of p have correct heights.
+*/
+static void amatchAvlRecomputeHeight(amatch_avl *p){
+  short int hBefore = p->pBefore ? p->pBefore->height : 0;
+  short int hAfter = p->pAfter ? p->pAfter->height : 0;
+  p->imbalance = hBefore - hAfter;  /* -: pAfter higher.  +: pBefore higher */
+  p->height = (hBefore>hAfter ? hBefore : hAfter)+1;
+}
+
+/*
+**     P                B
+**    / \              / \
+**   B   Z    ==>     X   P
+**  / \                  / \
+** X   Y                Y   Z
+**
+*/
+static amatch_avl *amatchAvlRotateBefore(amatch_avl *pP){
+  amatch_avl *pB = pP->pBefore;
+  amatch_avl *pY = pB->pAfter;
+  pB->pUp = pP->pUp;
+  pB->pAfter = pP;
+  pP->pUp = pB;
+  pP->pBefore = pY;
+  if( pY ) pY->pUp = pP;
+  amatchAvlRecomputeHeight(pP);
+  amatchAvlRecomputeHeight(pB);
+  return pB;
+}
+
+/*
+**     P                A
+**    / \              / \
+**   X   A    ==>     P   Z
+**      / \          / \
+**     Y   Z        X   Y
+**
+*/
+static amatch_avl *amatchAvlRotateAfter(amatch_avl *pP){
+  amatch_avl *pA = pP->pAfter;
+  amatch_avl *pY = pA->pBefore;
+  pA->pUp = pP->pUp;
+  pA->pBefore = pP;
+  pP->pUp = pA;
+  pP->pAfter = pY;
+  if( pY ) pY->pUp = pP;
+  amatchAvlRecomputeHeight(pP);
+  amatchAvlRecomputeHeight(pA);
+  return pA;
+}
+
+/*
+** Return a pointer to the pBefore or pAfter pointer in the parent
+** of p that points to p.  Or if p is the root node, return pp.
+*/
+static amatch_avl **amatchAvlFromPtr(amatch_avl *p, amatch_avl **pp){
+  amatch_avl *pUp = p->pUp;
+  if( pUp==0 ) return pp;
+  if( pUp->pAfter==p ) return &pUp->pAfter;
+  return &pUp->pBefore;
+}
+
+/*
+** Rebalance all nodes starting with p and working up to the root.
+** Return the new root.
+*/
+static amatch_avl *amatchAvlBalance(amatch_avl *p){
+  amatch_avl *pTop = p;
+  amatch_avl **pp;
+  while( p ){
+    amatchAvlRecomputeHeight(p);
+    if( p->imbalance>=2 ){
+      amatch_avl *pB = p->pBefore;
+      if( pB->imbalance<0 ) p->pBefore = amatchAvlRotateAfter(pB);
+      pp = amatchAvlFromPtr(p,&p);
+      p = *pp = amatchAvlRotateBefore(p);
+    }else if( p->imbalance<=(-2) ){
+      amatch_avl *pA = p->pAfter;
+      if( pA->imbalance>0 ) p->pAfter = amatchAvlRotateBefore(pA);
+      pp = amatchAvlFromPtr(p,&p);
+      p = *pp = amatchAvlRotateAfter(p);
+    }
+    pTop = p;
+    p = p->pUp;
+  }
+  return pTop;
+}
+
+/* Search the tree rooted at p for an entry with zKey.  Return a pointer
+** to the entry or return NULL.
+*/
+static amatch_avl *amatchAvlSearch(amatch_avl *p, const char *zKey){
+  int c;
+  while( p && (c = strcmp(zKey, p->zKey))!=0 ){
+    p = (c<0) ? p->pBefore : p->pAfter;
+  }
+  return p;
+}
+
+/* Find the first node (the one with the smallest key).
+*/
+static amatch_avl *amatchAvlFirst(amatch_avl *p){
+  if( p ) while( p->pBefore ) p = p->pBefore;
+  return p;
+}
+
+#if 0 /* NOT USED */
+/* Return the node with the next larger key after p.
+*/
+static amatch_avl *amatchAvlNext(amatch_avl *p){
+  amatch_avl *pPrev = 0;
+  while( p && p->pAfter==pPrev ){
+    pPrev = p;
+    p = p->pUp;
+  }
+  if( p && pPrev==0 ){
+    p = amatchAvlFirst(p->pAfter);
+  }
+  return p;
+}
+#endif
+
+#if 0 /* NOT USED */
+/* Verify AVL tree integrity
+*/
+static int amatchAvlIntegrity(amatch_avl *pHead){
+  amatch_avl *p;
+  if( pHead==0 ) return 1;
+  if( (p = pHead->pBefore)!=0 ){
+    assert( p->pUp==pHead );
+    assert( amatchAvlIntegrity(p) );
+    assert( strcmp(p->zKey, pHead->zKey)<0 );
+    while( p->pAfter ) p = p->pAfter;
+    assert( strcmp(p->zKey, pHead->zKey)<0 );
+  }
+  if( (p = pHead->pAfter)!=0 ){
+    assert( p->pUp==pHead );
+    assert( amatchAvlIntegrity(p) );
+    assert( strcmp(p->zKey, pHead->zKey)>0 );
+    p = amatchAvlFirst(p);
+    assert( strcmp(p->zKey, pHead->zKey)>0 );
+  }
+  return 1;
+}
+static int amatchAvlIntegrity2(amatch_avl *pHead){
+  amatch_avl *p, *pNext;
+  for(p=amatchAvlFirst(pHead); p; p=pNext){
+    pNext = amatchAvlNext(p);
+    if( pNext==0 ) break;
+    assert( strcmp(p->zKey, pNext->zKey)<0 );
+  }
+  return 1;
+}
+#endif
+
+/* Insert a new node pNew.  Return NULL on success.  If the key is not
+** unique, then do not perform the insert but instead leave pNew unchanged
+** and return a pointer to an existing node with the same key.
+*/
+static amatch_avl *amatchAvlInsert(amatch_avl **ppHead, amatch_avl *pNew){
+  int c;
+  amatch_avl *p = *ppHead;
+  if( p==0 ){
+    p = pNew;
+    pNew->pUp = 0;
+  }else{
+    while( p ){
+      c = strcmp(pNew->zKey, p->zKey);
+      if( c<0 ){
+        if( p->pBefore ){
+          p = p->pBefore;
+        }else{
+          p->pBefore = pNew;
+          pNew->pUp = p;
+          break;
+        }
+      }else if( c>0 ){
+        if( p->pAfter ){
+          p = p->pAfter;
+        }else{
+          p->pAfter = pNew;
+          pNew->pUp = p;
+          break;
+        }
+      }else{
+        return p;
+      }
+    }
+  }
+  pNew->pBefore = 0;
+  pNew->pAfter = 0;
+  pNew->height = 1;
+  pNew->imbalance = 0;
+  *ppHead = amatchAvlBalance(p);
+  /* assert( amatchAvlIntegrity(*ppHead) ); */
+  /* assert( amatchAvlIntegrity2(*ppHead) ); */
+  return 0;
+}
+
+/* Remove node pOld from the tree.  pOld must be an element of the tree or
+** the AVL tree will become corrupt.
+*/
+static void amatchAvlRemove(amatch_avl **ppHead, amatch_avl *pOld){
+  amatch_avl **ppParent;
+  amatch_avl *pBalance;
+  /* assert( amatchAvlSearch(*ppHead, pOld->zKey)==pOld ); */
+  ppParent = amatchAvlFromPtr(pOld, ppHead);
+  if( pOld->pBefore==0 && pOld->pAfter==0 ){
+    *ppParent = 0;
+    pBalance = pOld->pUp;
+  }else if( pOld->pBefore && pOld->pAfter ){
+    amatch_avl *pX, *pY;
+    pX = amatchAvlFirst(pOld->pAfter);
+    *amatchAvlFromPtr(pX, 0) = pX->pAfter;
+    if( pX->pAfter ) pX->pAfter->pUp = pX->pUp;
+    pBalance = pX->pUp;
+    pX->pAfter = pOld->pAfter;
+    if( pX->pAfter ){
+      pX->pAfter->pUp = pX;
+    }else{
+      assert( pBalance==pOld );
+      pBalance = pX;
+    }
+    pX->pBefore = pY = pOld->pBefore;
+    if( pY ) pY->pUp = pX;
+    pX->pUp = pOld->pUp;
+    *ppParent = pX;
+  }else if( pOld->pBefore==0 ){
+    *ppParent = pBalance = pOld->pAfter;
+    pBalance->pUp = pOld->pUp;
+  }else if( pOld->pAfter==0 ){
+    *ppParent = pBalance = pOld->pBefore;
+    pBalance->pUp = pOld->pUp;
+  }
+  *ppHead = amatchAvlBalance(pBalance);
+  pOld->pUp = 0;
+  pOld->pBefore = 0;
+  pOld->pAfter = 0;
+  /* assert( amatchAvlIntegrity(*ppHead) ); */
+  /* assert( amatchAvlIntegrity2(*ppHead) ); */
+}
+/*
+** End of the AVL Tree implementation
+******************************************************************************/
+
+
+/*
+** Various types.
+**
+** amatch_cost is the "cost" of an edit operation.
+**
+** amatch_len is the length of a matching string.  
+**
+** amatch_langid is an ruleset identifier.
+*/
+typedef int amatch_cost;
+typedef signed char amatch_len;
+typedef int amatch_langid;
+
+/*
+** Limits
+*/
+#define AMATCH_MX_LENGTH          50  /* Maximum length of a rule string */
+#define AMATCH_MX_LANGID  2147483647  /* Maximum rule ID */
+#define AMATCH_MX_COST          1000  /* Maximum single-rule cost */
+
+/*
+** A match or partial match
+*/
+struct amatch_word {
+  amatch_word *pNext;   /* Next on a list of all amatch_words */
+  amatch_avl sCost;     /* Linkage of this node into the cost tree */
+  amatch_avl sWord;     /* Linkage of this node into the word tree */
+  amatch_cost rCost;    /* Cost of the match so far */
+  int iSeq;             /* Sequence number */
+  char zCost[10];       /* Cost key (text rendering of rCost) */
+  short int nMatch;     /* Input characters matched */
+  char zWord[4];        /* Text of the word.  Extra space appended as needed */
+};
+
+/*
+** Each transformation rule is stored as an instance of this object.
+** All rules are kept on a linked list sorted by rCost.
+*/
+struct amatch_rule {
+  amatch_rule *pNext;      /* Next rule in order of increasing rCost */
+  char *zFrom;             /* Transform from (a string from user input) */
+  amatch_cost rCost;       /* Cost of this transformation */
+  amatch_langid iLang;     /* The langauge to which this rule belongs */
+  amatch_len nFrom, nTo;   /* Length of the zFrom and zTo strings */
+  char zTo[4];             /* Tranform to V.W value (extra space appended) */
+};
+
+/* 
+** A amatch virtual-table object 
+*/
+struct amatch_vtab {
+  sqlite3_vtab base;         /* Base class - must be first */
+  char *zClassName;          /* Name of this class.  Default: "amatch" */
+  char *zDb;                 /* Name of database.  (ex: "main") */
+  char *zSelf;               /* Name of this virtual table */
+  char *zCostTab;            /* Name of edit-cost-table */
+  char *zVocabTab;           /* Name of vocabulary table */
+  char *zVocabWord;          /* Name of vocabulary table word column */
+  char *zVocabLang;          /* Name of vocabulary table language column */
+  amatch_rule *pRule;        /* All active rules in this amatch */
+  amatch_cost rIns;          /* Generic insertion cost  '' -> ? */
+  amatch_cost rDel;          /* Generic deletion cost  ? -> '' */
+  amatch_cost rSub;          /* Generic substitution cost ? -> ? */
+  sqlite3 *db;               /* The database connection */
+  sqlite3_stmt *pVCheck;     /* Query to check zVocabTab */
+  int nCursor;               /* Number of active cursors */
+};
+
+/* A amatch cursor object */
+struct amatch_cursor {
+  sqlite3_vtab_cursor base;  /* Base class - must be first */
+  sqlite3_int64 iRowid;      /* The rowid of the current word */
+  amatch_langid iLang;       /* Use this language ID */
+  amatch_cost rLimit;        /* Maximum cost of any term */
+  int nBuf;                  /* Space allocated for zBuf */
+  int oomErr;                /* True following an OOM error */
+  int nWord;                 /* Number of amatch_word objects */
+  char *zBuf;                /* Temp-use buffer space */
+  char *zInput;              /* Input word to match against */
+  amatch_vtab *pVtab;        /* The virtual table this cursor belongs to */
+  amatch_word *pAllWords;    /* List of all amatch_word objects */
+  amatch_word *pCurrent;     /* Most recent solution */
+  amatch_avl *pCost;         /* amatch_word objects keyed by iCost */
+  amatch_avl *pWord;         /* amatch_word objects keyed by zWord */
+};
+
+/*
+** The two input rule lists are both sorted in order of increasing
+** cost.  Merge them together into a single list, sorted by cost, and
+** return a pointer to the head of that list.
+*/
+static amatch_rule *amatchMergeRules(amatch_rule *pA, amatch_rule *pB){
+  amatch_rule head;
+  amatch_rule *pTail;
+
+  pTail =  &head;
+  while( pA && pB ){
+    if( pA->rCost<=pB->rCost ){
+      pTail->pNext = pA;
+      pTail = pA;
+      pA = pA->pNext;
+    }else{
+      pTail->pNext = pB;
+      pTail = pB;
+      pB = pB->pNext;
+    }
+  }
+  if( pA==0 ){
+    pTail->pNext = pB;
+  }else{
+    pTail->pNext = pA;
+  }
+  return head.pNext;
+}
+
+/*
+** Statement pStmt currently points to a row in the amatch data table. This
+** function allocates and populates a amatch_rule structure according to
+** the content of the row.
+**
+** If successful, *ppRule is set to point to the new object and SQLITE_OK
+** is returned. Otherwise, *ppRule is zeroed, *pzErr may be set to point
+** to an error message and an SQLite error code returned.
+*/
+static int amatchLoadOneRule(
+  amatch_vtab *p,                 /* Fuzzer virtual table handle */
+  sqlite3_stmt *pStmt,            /* Base rule on statements current row */
+  amatch_rule **ppRule,           /* OUT: New rule object */
+  char **pzErr                    /* OUT: Error message */
+){
+  sqlite3_int64 iLang = sqlite3_column_int64(pStmt, 0);
+  const char *zFrom = (const char *)sqlite3_column_text(pStmt, 1);
+  const char *zTo = (const char *)sqlite3_column_text(pStmt, 2);
+  amatch_cost rCost = sqlite3_column_int(pStmt, 3);
+
+  int rc = SQLITE_OK;             /* Return code */
+  int nFrom;                      /* Size of string zFrom, in bytes */
+  int nTo;                        /* Size of string zTo, in bytes */
+  amatch_rule *pRule = 0;         /* New rule object to return */
+
+  if( zFrom==0 ) zFrom = "";
+  if( zTo==0 ) zTo = "";
+  nFrom = (int)strlen(zFrom);
+  nTo = (int)strlen(zTo);
+
+  /* Silently ignore null transformations */
+  if( strcmp(zFrom, zTo)==0 ){
+    if( zFrom[0]=='?' && zFrom[1]==0 ){
+      if( p->rSub==0 || p->rSub>rCost ) p->rSub = rCost;
+    }
+    *ppRule = 0;
+    return SQLITE_OK;
+  }
+
+  if( rCost<=0 || rCost>AMATCH_MX_COST ){
+    *pzErr = sqlite3_mprintf("%s: cost must be between 1 and %d", 
+        p->zClassName, AMATCH_MX_COST
+    );
+    rc = SQLITE_ERROR;
+  }else
+  if( nFrom>AMATCH_MX_LENGTH || nTo>AMATCH_MX_LENGTH ){
+    *pzErr = sqlite3_mprintf("%s: maximum string length is %d", 
+        p->zClassName, AMATCH_MX_LENGTH
+    );
+    rc = SQLITE_ERROR;    
+  }else
+  if( iLang<0 || iLang>AMATCH_MX_LANGID ){
+    *pzErr = sqlite3_mprintf("%s: iLang must be between 0 and %d", 
+        p->zClassName, AMATCH_MX_LANGID
+    );
+    rc = SQLITE_ERROR;    
+  }else
+  if( strcmp(zFrom,"")==0 && strcmp(zTo,"?")==0 ){
+    if( p->rIns==0 || p->rIns>rCost ) p->rIns = rCost;
+  }else
+  if( strcmp(zFrom,"?")==0 && strcmp(zTo,"")==0 ){
+    if( p->rDel==0 || p->rDel>rCost ) p->rDel = rCost;
+  }else
+  {
+    pRule = sqlite3_malloc( sizeof(*pRule) + nFrom + nTo );
+    if( pRule==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pRule, 0, sizeof(*pRule));
+      pRule->zFrom = &pRule->zTo[nTo+1];
+      pRule->nFrom = nFrom;
+      memcpy(pRule->zFrom, zFrom, nFrom+1);
+      memcpy(pRule->zTo, zTo, nTo+1);
+      pRule->nTo = nTo;
+      pRule->rCost = rCost;
+      pRule->iLang = (int)iLang;
+    }
+  }
+
+  *ppRule = pRule;
+  return rc;
+}
+
+/*
+** Free all the content in the edit-cost-table
+*/
+static void amatchFreeRules(amatch_vtab *p){
+  while( p->pRule ){
+    amatch_rule *pRule = p->pRule;
+    p->pRule = pRule->pNext;
+    sqlite3_free(pRule);
+  }
+  p->pRule = 0;
+}
+
+/*
+** Load the content of the amatch data table into memory.
+*/
+static int amatchLoadRules(
+  sqlite3 *db,                    /* Database handle */
+  amatch_vtab *p,                 /* Virtual amatch table to configure */
+  char **pzErr                    /* OUT: Error message */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  char *zSql;                     /* SELECT used to read from rules table */
+  amatch_rule *pHead = 0;
+
+  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", p->zDb, p->zCostTab);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    int rc2;                      /* finalize() return code */
+    sqlite3_stmt *pStmt = 0;
+    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3_mprintf("%s: %s", p->zClassName, sqlite3_errmsg(db));
+    }else if( sqlite3_column_count(pStmt)!=4 ){
+      *pzErr = sqlite3_mprintf("%s: %s has %d columns, expected 4",
+          p->zClassName, p->zCostTab, sqlite3_column_count(pStmt)
+      );
+      rc = SQLITE_ERROR;
+    }else{
+      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+        amatch_rule *pRule = 0;
+        rc = amatchLoadOneRule(p, pStmt, &pRule, pzErr);
+        if( pRule ){
+          pRule->pNext = pHead;
+          pHead = pRule;
+        }
+      }
+    }
+    rc2 = sqlite3_finalize(pStmt);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+  sqlite3_free(zSql);
+
+  /* All rules are now in a singly linked list starting at pHead. This
+  ** block sorts them by cost and then sets amatch_vtab.pRule to point to 
+  ** point to the head of the sorted list.
+  */
+  if( rc==SQLITE_OK ){
+    unsigned int i;
+    amatch_rule *pX;
+    amatch_rule *a[15];
+    for(i=0; i<sizeof(a)/sizeof(a[0]); i++) a[i] = 0;
+    while( (pX = pHead)!=0 ){
+      pHead = pX->pNext;
+      pX->pNext = 0;
+      for(i=0; a[i] && i<sizeof(a)/sizeof(a[0])-1; i++){
+        pX = amatchMergeRules(a[i], pX);
+        a[i] = 0;
+      }
+      a[i] = amatchMergeRules(a[i], pX);
+    }
+    for(pX=a[0], i=1; i<sizeof(a)/sizeof(a[0]); i++){
+      pX = amatchMergeRules(a[i], pX);
+    }
+    p->pRule = amatchMergeRules(p->pRule, pX);
+  }else{
+    /* An error has occurred. Setting p->pRule to point to the head of the
+    ** allocated list ensures that the list will be cleaned up in this case.
+    */
+    assert( p->pRule==0 );
+    p->pRule = pHead;
+  }
+
+  return rc;
+}
+
+/*
+** This function converts an SQL quoted string into an unquoted string
+** and returns a pointer to a buffer allocated using sqlite3_malloc() 
+** containing the result. The caller should eventually free this buffer
+** using sqlite3_free.
+**
+** Examples:
+**
+**     "abc"   becomes   abc
+**     'xyz'   becomes   xyz
+**     [pqr]   becomes   pqr
+**     `mno`   becomes   mno
+*/
+static char *amatchDequote(const char *zIn){
+  int nIn;                        /* Size of input string, in bytes */
+  char *zOut;                     /* Output (dequoted) string */
+
+  nIn = (int)strlen(zIn);
+  zOut = sqlite3_malloc(nIn+1);
+  if( zOut ){
+    char q = zIn[0];              /* Quote character (if any ) */
+
+    if( q!='[' && q!= '\'' && q!='"' && q!='`' ){
+      memcpy(zOut, zIn, nIn+1);
+    }else{
+      int iOut = 0;               /* Index of next byte to write to output */
+      int iIn;                    /* Index of next byte to read from input */
+
+      if( q=='[' ) q = ']';
+      for(iIn=1; iIn<nIn; iIn++){
+        if( zIn[iIn]==q ) iIn++;
+        zOut[iOut++] = zIn[iIn];
+      }
+    }
+    assert( (int)strlen(zOut)<=nIn );
+  }
+  return zOut;
+}
+
+/*
+** Deallocate the pVCheck prepared statement.
+*/
+static void amatchVCheckClear(amatch_vtab *p){
+  if( p->pVCheck ){
+    sqlite3_finalize(p->pVCheck);
+    p->pVCheck = 0;
+  }
+}
+
+/*
+** Deallocate an amatch_vtab object
+*/
+static void amatchFree(amatch_vtab *p){
+  if( p ){
+    amatchFreeRules(p);
+    amatchVCheckClear(p);
+    sqlite3_free(p->zClassName);
+    sqlite3_free(p->zDb);
+    sqlite3_free(p->zCostTab);
+    sqlite3_free(p->zVocabTab);
+    sqlite3_free(p->zVocabWord);
+    sqlite3_free(p->zVocabLang);
+    memset(p, 0, sizeof(*p));
+    sqlite3_free(p);
+  }
+}
+
+/*
+** xDisconnect/xDestroy method for the amatch module.
+*/
+static int amatchDisconnect(sqlite3_vtab *pVtab){
+  amatch_vtab *p = (amatch_vtab*)pVtab;
+  assert( p->nCursor==0 );
+  amatchFree(p);
+  return SQLITE_OK;
+}
+
+/*
+** Check to see if the argument is of the form:
+**
+**       KEY = VALUE
+**
+** If it is, return a pointer to the first character of VALUE.
+** If not, return NULL.  Spaces around the = are ignored.
+*/
+static const char *amatchValueOfKey(const char *zKey, const char *zStr){
+  int nKey = (int)strlen(zKey);
+  int nStr = (int)strlen(zStr);
+  int i;
+  if( nStr<nKey+1 ) return 0;
+  if( memcmp(zStr, zKey, nKey)!=0 ) return 0;
+  for(i=nKey; isspace(zStr[i]); i++){}
+  if( zStr[i]!='=' ) return 0;
+  i++;
+  while( isspace(zStr[i]) ){ i++; }
+  return zStr+i;
+}
+
+/*
+** xConnect/xCreate method for the amatch module. Arguments are:
+**
+**   argv[0]    -> module name  ("approximate_match")
+**   argv[1]    -> database name
+**   argv[2]    -> table name
+**   argv[3...] -> arguments
+*/
+static int amatchConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc = SQLITE_OK;             /* Return code */
+  amatch_vtab *pNew = 0;          /* New virtual table */
+  const char *zModule = argv[0];
+  const char *zDb = argv[1];
+  const char *zVal;
+  int i;
+
+  (void)pAux;
+  *ppVtab = 0;
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  if( pNew==0 ) return SQLITE_NOMEM;
+  rc = SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  pNew->db = db;
+  pNew->zClassName = sqlite3_mprintf("%s", zModule);
+  if( pNew->zClassName==0 ) goto amatchConnectError;
+  pNew->zDb = sqlite3_mprintf("%s", zDb);
+  if( pNew->zDb==0 ) goto amatchConnectError;
+  pNew->zSelf = sqlite3_mprintf("%s", argv[2]);
+  if( pNew->zSelf==0 ) goto amatchConnectError;
+  for(i=3; i<argc; i++){
+    zVal = amatchValueOfKey("vocabulary_table", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zVocabTab);
+      pNew->zVocabTab = amatchDequote(zVal);
+      if( pNew->zVocabTab==0 ) goto amatchConnectError;
+      continue;
+    }
+    zVal = amatchValueOfKey("vocabulary_word", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zVocabWord);
+      pNew->zVocabWord = amatchDequote(zVal);
+      if( pNew->zVocabWord==0 ) goto amatchConnectError;
+      continue;
+    }
+    zVal = amatchValueOfKey("vocabulary_language", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zVocabLang);
+      pNew->zVocabLang = amatchDequote(zVal);
+      if( pNew->zVocabLang==0 ) goto amatchConnectError;
+      continue;
+    }
+    zVal = amatchValueOfKey("edit_distances", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zCostTab);
+      pNew->zCostTab = amatchDequote(zVal);
+      if( pNew->zCostTab==0 ) goto amatchConnectError;
+      continue;
+    }
+    *pzErr = sqlite3_mprintf("unrecognized argument: [%s]\n", argv[i]);
+    amatchFree(pNew);
+    *ppVtab = 0;
+    return SQLITE_ERROR;
+  }
+  rc = SQLITE_OK;
+  if( pNew->zCostTab==0 ){
+    *pzErr = sqlite3_mprintf("no edit_distances table specified");
+    rc = SQLITE_ERROR;
+  }else{
+    rc = amatchLoadRules(db, pNew, pzErr);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_declare_vtab(db,
+           "CREATE TABLE x(word,distance,language,"
+           "command HIDDEN,nword HIDDEN)"
+         );
+#define AMATCH_COL_WORD       0
+#define AMATCH_COL_DISTANCE   1
+#define AMATCH_COL_LANGUAGE   2
+#define AMATCH_COL_COMMAND    3
+#define AMATCH_COL_NWORD      4
+  }
+  if( rc!=SQLITE_OK ){
+    amatchFree(pNew);
+  }
+  *ppVtab = &pNew->base;
+  return rc;
+
+amatchConnectError:
+  amatchFree(pNew);
+  return rc;
+}
+
+/*
+** Open a new amatch cursor.
+*/
+static int amatchOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  amatch_vtab *p = (amatch_vtab*)pVTab;
+  amatch_cursor *pCur;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  pCur->pVtab = p;
+  *ppCursor = &pCur->base;
+  p->nCursor++;
+  return SQLITE_OK;
+}
+
+/*
+** Free up all the memory allocated by a cursor.  Set it rLimit to 0
+** to indicate that it is at EOF.
+*/
+static void amatchClearCursor(amatch_cursor *pCur){
+  amatch_word *pWord, *pNextWord;
+  for(pWord=pCur->pAllWords; pWord; pWord=pNextWord){
+    pNextWord = pWord->pNext;
+    sqlite3_free(pWord);
+  }
+  pCur->pAllWords = 0;
+  sqlite3_free(pCur->zInput);
+  pCur->zInput = 0;
+  pCur->pCost = 0;
+  pCur->pWord = 0;
+  pCur->pCurrent = 0;
+  pCur->rLimit = 1000000;
+  pCur->iLang = 0;
+  pCur->nWord = 0;
+}
+
+/*
+** Close a amatch cursor.
+*/
+static int amatchClose(sqlite3_vtab_cursor *cur){
+  amatch_cursor *pCur = (amatch_cursor *)cur;
+  amatchClearCursor(pCur);
+  pCur->pVtab->nCursor--;
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Render a 24-bit unsigned integer as a 4-byte base-64 number.
+*/
+static void amatchEncodeInt(int x, char *z){
+  static const char a[] = 
+    "0123456789"
+    "ABCDEFGHIJ"
+    "KLMNOPQRST"
+    "UVWXYZ^abc"
+    "defghijklm"
+    "nopqrstuvw"
+    "xyz~";
+  z[0] = a[(x>>18)&0x3f];
+  z[1] = a[(x>>12)&0x3f];
+  z[2] = a[(x>>6)&0x3f];
+  z[3] = a[x&0x3f];
+}
+
+/*
+** Write the zCost[] field for a amatch_word object
+*/
+static void amatchWriteCost(amatch_word *pWord){
+  amatchEncodeInt(pWord->rCost, pWord->zCost);
+  amatchEncodeInt(pWord->iSeq, pWord->zCost+4);
+  pWord->zCost[8] = 0;
+}
+
+/*
+** Add a new amatch_word object to the queue.
+**
+** If a prior amatch_word object with the same zWord, and nMatch
+** already exists, update its rCost (if the new rCost is less) but
+** otherwise leave it unchanged.  Do not add a duplicate.
+**
+** Do nothing if the cost exceeds threshold.
+*/
+static void amatchAddWord(
+  amatch_cursor *pCur,
+  amatch_cost rCost,
+  int nMatch,
+  const char *zWordBase,
+  const char *zWordTail
+){
+  amatch_word *pWord;
+  amatch_avl *pNode;
+  amatch_avl *pOther;
+  int nBase, nTail;
+  char zBuf[4];
+  
+  if( rCost>pCur->rLimit ){
+    return;
+  }
+  nBase = (int)strlen(zWordBase);
+  nTail = (int)strlen(zWordTail);
+  if( nBase+nTail+3>pCur->nBuf ){
+    pCur->nBuf = nBase+nTail+100;
+    pCur->zBuf = sqlite3_realloc(pCur->zBuf, pCur->nBuf);
+    if( pCur->zBuf==0 ){
+      pCur->nBuf = 0;
+      return;
+    }
+  }
+  amatchEncodeInt(nMatch, zBuf);
+  memcpy(pCur->zBuf, zBuf+2, 2);
+  memcpy(pCur->zBuf+2, zWordBase, nBase);
+  memcpy(pCur->zBuf+2+nBase, zWordTail, nTail+1);
+  pNode = amatchAvlSearch(pCur->pWord, pCur->zBuf);
+  if( pNode ){
+    pWord = pNode->pWord;
+    if( pWord->rCost>rCost ){
+#ifdef AMATCH_TRACE_1
+      printf("UPDATE [%s][%.*s^%s] %d (\"%s\" \"%s\")\n",
+             pWord->zWord+2, pWord->nMatch, pCur->zInput, pCur->zInput,
+             pWord->rCost, pWord->zWord, pWord->zCost);
+#endif
+      amatchAvlRemove(&pCur->pCost, &pWord->sCost);
+      pWord->rCost = rCost;
+      amatchWriteCost(pWord);
+#ifdef AMATCH_TRACE_1
+      printf("  ---> %d (\"%s\" \"%s\")\n",
+             pWord->rCost, pWord->zWord, pWord->zCost);
+#endif
+      pOther = amatchAvlInsert(&pCur->pCost, &pWord->sCost);
+      assert( pOther==0 ); (void)pOther;
+    }
+    return;
+  }
+  pWord = sqlite3_malloc( sizeof(*pWord) + nBase + nTail - 1 );
+  if( pWord==0 ) return;
+  memset(pWord, 0, sizeof(*pWord));
+  pWord->rCost = rCost;
+  pWord->iSeq = pCur->nWord++;
+  amatchWriteCost(pWord);
+  pWord->nMatch = nMatch;
+  pWord->pNext = pCur->pAllWords;
+  pCur->pAllWords = pWord;
+  pWord->sCost.zKey = pWord->zCost;
+  pWord->sCost.pWord = pWord;
+  pOther = amatchAvlInsert(&pCur->pCost, &pWord->sCost);
+  assert( pOther==0 ); (void)pOther;
+  pWord->sWord.zKey = pWord->zWord;
+  pWord->sWord.pWord = pWord;
+  strcpy(pWord->zWord, pCur->zBuf);
+  pOther = amatchAvlInsert(&pCur->pWord, &pWord->sWord);
+  assert( pOther==0 ); (void)pOther;
+#ifdef AMATCH_TRACE_1
+  printf("INSERT [%s][%.*s^%s] %d (\"%s\" \"%s\")\n", pWord->zWord+2,
+       pWord->nMatch, pCur->zInput, pCur->zInput+pWord->nMatch, rCost,
+       pWord->zWord, pWord->zCost);
+#endif
+}
+
+/*
+** Advance a cursor to its next row of output
+*/
+static int amatchNext(sqlite3_vtab_cursor *cur){
+  amatch_cursor *pCur = (amatch_cursor*)cur;
+  amatch_word *pWord = 0;
+  amatch_avl *pNode;
+  int isMatch = 0;
+  amatch_vtab *p = pCur->pVtab;
+  int nWord;
+  int rc;
+  int i;
+  const char *zW;
+  amatch_rule *pRule;
+  char *zBuf = 0;
+  char nBuf = 0;
+  char zNext[8];
+  char zNextIn[8];
+  int nNextIn;
+
+  if( p->pVCheck==0 ){
+    char *zSql;
+    if( p->zVocabLang && p->zVocabLang[0] ){
+      zSql = sqlite3_mprintf(
+          "SELECT \"%s\" FROM \"%s\"",
+          " WHERE \"%w\">=?1 AND \"%w\"=?2"
+          " ORDER BY 1",
+          p->zVocabWord, p->zVocabTab,
+          p->zVocabWord, p->zVocabLang
+      );
+    }else{
+      zSql = sqlite3_mprintf(
+          "SELECT \"%s\" FROM \"%s\""
+          " WHERE \"%w\">=?1"
+          " ORDER BY 1",
+          p->zVocabWord, p->zVocabTab,
+          p->zVocabWord
+      );
+    }
+    rc = sqlite3_prepare_v2(p->db, zSql, -1, &p->pVCheck, 0);
+    sqlite3_free(zSql);
+    if( rc ) return rc;
+  }
+  sqlite3_bind_int(p->pVCheck, 2, pCur->iLang);
+
+  do{
+    pNode = amatchAvlFirst(pCur->pCost);
+    if( pNode==0 ){
+      pWord = 0;
+      break;
+    }
+    pWord = pNode->pWord;
+    amatchAvlRemove(&pCur->pCost, &pWord->sCost);
+
+#ifdef AMATCH_TRACE_1
+    printf("PROCESS [%s][%.*s^%s] %d (\"%s\" \"%s\")\n",
+       pWord->zWord+2, pWord->nMatch, pCur->zInput, pCur->zInput+pWord->nMatch,
+       pWord->rCost, pWord->zWord, pWord->zCost);
+#endif
+    nWord = (int)strlen(pWord->zWord+2);
+    if( nWord+20>nBuf ){
+      nBuf = nWord+100;
+      zBuf = sqlite3_realloc(zBuf, nBuf);
+      if( zBuf==0 ) return SQLITE_NOMEM;
+    }
+    strcpy(zBuf, pWord->zWord+2);
+    zNext[0] = 0;
+    zNextIn[0] = pCur->zInput[pWord->nMatch];
+    if( zNextIn[0] ){
+      for(i=1; i<=4 && (pCur->zInput[pWord->nMatch+i]&0xc0)==0x80; i++){
+        zNextIn[i] = pCur->zInput[pWord->nMatch+i];
+      }
+      zNextIn[i] = 0;
+      nNextIn = i;
+    }else{
+      nNextIn = 0;
+    }
+
+    if( zNextIn[0] && zNextIn[0]!='*' ){
+      sqlite3_reset(p->pVCheck);
+      strcat(zBuf, zNextIn);
+      sqlite3_bind_text(p->pVCheck, 1, zBuf, nWord+nNextIn, SQLITE_STATIC);
+      rc = sqlite3_step(p->pVCheck);
+      if( rc==SQLITE_ROW ){
+        zW = (const char*)sqlite3_column_text(p->pVCheck, 0);
+        if( strncmp(zBuf, zW, nWord+nNextIn)==0 ){
+          amatchAddWord(pCur, pWord->rCost, pWord->nMatch+nNextIn, zBuf, "");
+        }
+      }
+      zBuf[nWord] = 0;
+    }
+
+    while( 1 ){
+      strcpy(zBuf+nWord, zNext);
+      sqlite3_reset(p->pVCheck);
+      sqlite3_bind_text(p->pVCheck, 1, zBuf, -1, SQLITE_TRANSIENT);
+      rc = sqlite3_step(p->pVCheck);
+      if( rc!=SQLITE_ROW ) break;
+      zW = (const char*)sqlite3_column_text(p->pVCheck, 0);
+      strcpy(zBuf+nWord, zNext);
+      if( strncmp(zW, zBuf, nWord)!=0 ) break;
+      if( (zNextIn[0]=='*' && zNextIn[1]==0)
+       || (zNextIn[0]==0 && zW[nWord]==0)
+      ){
+        isMatch = 1;
+        zNextIn[0] = 0;
+        nNextIn = 0;
+        break;
+      }
+      zNext[0] = zW[nWord];
+      for(i=1; i<=4 && (zW[nWord+i]&0xc0)==0x80; i++){
+        zNext[i] = zW[nWord+i];
+      }
+      zNext[i] = 0;
+      zBuf[nWord] = 0;
+      if( p->rIns>0 ){
+        amatchAddWord(pCur, pWord->rCost+p->rIns, pWord->nMatch, 
+                      zBuf, zNext);
+      }
+      if( p->rSub>0 ){
+        amatchAddWord(pCur, pWord->rCost+p->rSub, pWord->nMatch+nNextIn, 
+                      zBuf, zNext);
+      }
+      if( p->rIns<0 && p->rSub<0 ) break;
+      zNext[i-1]++;  /* FIX ME */
+    }
+    sqlite3_reset(p->pVCheck);
+
+    if( p->rDel>0 ){
+      zBuf[nWord] = 0;
+      amatchAddWord(pCur, pWord->rCost+p->rDel, pWord->nMatch+nNextIn,
+                    zBuf, "");
+    }
+
+    for(pRule=p->pRule; pRule; pRule=pRule->pNext){
+      if( pRule->iLang!=pCur->iLang ) continue;
+      if( strncmp(pRule->zFrom, pCur->zInput+pWord->nMatch, pRule->nFrom)==0 ){
+        amatchAddWord(pCur, pWord->rCost+pRule->rCost,
+                      pWord->nMatch+pRule->nFrom, pWord->zWord+2, pRule->zTo);
+      }
+    }
+  }while( !isMatch );
+  pCur->pCurrent = pWord;
+  sqlite3_free(zBuf);
+  return SQLITE_OK;
+}
+
+/*
+** Called to "rewind" a cursor back to the beginning so that
+** it starts its output over again.  Always called at least once
+** prior to any amatchColumn, amatchRowid, or amatchEof call.
+*/
+static int amatchFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  amatch_cursor *pCur = (amatch_cursor *)pVtabCursor;
+  const char *zWord = "*";
+  int idx;
+
+  amatchClearCursor(pCur);
+  idx = 0;
+  if( idxNum & 1 ){
+    zWord = (const char*)sqlite3_value_text(argv[0]);
+    idx++;
+  }
+  if( idxNum & 2 ){
+    pCur->rLimit = (amatch_cost)sqlite3_value_int(argv[idx]);
+    idx++;
+  }
+  if( idxNum & 4 ){
+    pCur->iLang = (amatch_cost)sqlite3_value_int(argv[idx]);
+    idx++;
+  }
+  pCur->zInput = sqlite3_mprintf("%s", zWord);
+  if( pCur->zInput==0 ) return SQLITE_NOMEM;
+  amatchAddWord(pCur, 0, 0, "", "");
+  amatchNext(pVtabCursor);
+
+  return SQLITE_OK;
+}
+
+/*
+** Only the word and distance columns have values.  All other columns
+** return NULL
+*/
+static int amatchColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  amatch_cursor *pCur = (amatch_cursor*)cur;
+  switch( i ){
+    case AMATCH_COL_WORD: {
+      sqlite3_result_text(ctx, pCur->pCurrent->zWord+2, -1, SQLITE_STATIC);
+      break;
+    }
+    case AMATCH_COL_DISTANCE: {
+      sqlite3_result_int(ctx, pCur->pCurrent->rCost);
+      break;
+    }
+    case AMATCH_COL_LANGUAGE: {
+      sqlite3_result_int(ctx, pCur->iLang);
+      break;
+    }
+    case AMATCH_COL_NWORD: {
+      sqlite3_result_int(ctx, pCur->nWord);
+      break;
+    }
+    default: {
+      sqlite3_result_null(ctx);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The rowid.
+*/
+static int amatchRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  amatch_cursor *pCur = (amatch_cursor*)cur;
+  *pRowid = pCur->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** EOF indicator
+*/
+static int amatchEof(sqlite3_vtab_cursor *cur){
+  amatch_cursor *pCur = (amatch_cursor*)cur;
+  return pCur->pCurrent==0;
+}
+
+/*
+** Search for terms of these forms:
+**
+**   (A)    word MATCH $str
+**   (B1)   distance < $value
+**   (B2)   distance <= $value
+**   (C)    language == $language
+**
+** The distance< and distance<= are both treated as distance<=.
+** The query plan number is a bit vector:
+**
+**   bit 1:   Term of the form (A) found
+**   bit 2:   Term like (B1) or (B2) found
+**   bit 3:   Term like (C) found
+**
+** If bit-1 is set, $str is always in filter.argv[0].  If bit-2 is set
+** then $value is in filter.argv[0] if bit-1 is clear and is in 
+** filter.argv[1] if bit-1 is set.  If bit-3 is set, then $ruleid is
+** in filter.argv[0] if bit-1 and bit-2 are both zero, is in
+** filter.argv[1] if exactly one of bit-1 and bit-2 are set, and is in
+** filter.argv[2] if both bit-1 and bit-2 are set.
+*/
+static int amatchBestIndex(
+  sqlite3_vtab *tab,
+  sqlite3_index_info *pIdxInfo
+){
+  int iPlan = 0;
+  int iDistTerm = -1;
+  int iLangTerm = -1;
+  int i;
+  const struct sqlite3_index_constraint *pConstraint;
+
+  (void)tab;
+  pConstraint = pIdxInfo->aConstraint;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( (iPlan & 1)==0 
+     && pConstraint->iColumn==0
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH
+    ){
+      iPlan |= 1;
+      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+    if( (iPlan & 2)==0
+     && pConstraint->iColumn==1
+     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
+           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
+    ){
+      iPlan |= 2;
+      iDistTerm = i;
+    }
+    if( (iPlan & 4)==0
+     && pConstraint->iColumn==2
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 4;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+      iLangTerm = i;
+    }
+  }
+  if( iPlan & 2 ){
+    pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = 1+((iPlan&1)!=0);
+  }
+  if( iPlan & 4 ){
+    int idx = 1;
+    if( iPlan & 1 ) idx++;
+    if( iPlan & 2 ) idx++;
+    pIdxInfo->aConstraintUsage[iLangTerm].argvIndex = idx;
+  }
+  pIdxInfo->idxNum = iPlan;
+  if( pIdxInfo->nOrderBy==1
+   && pIdxInfo->aOrderBy[0].iColumn==1
+   && pIdxInfo->aOrderBy[0].desc==0
+  ){
+    pIdxInfo->orderByConsumed = 1;
+  }
+  pIdxInfo->estimatedCost = (double)10000;
+   
+  return SQLITE_OK;
+}
+
+/*
+** The xUpdate() method.  
+**
+** This implementation disallows DELETE and UPDATE.  The only thing
+** allowed is INSERT into the "command" column.
+*/
+static int amatchUpdate(
+  sqlite3_vtab *pVTab,
+  int argc,
+  sqlite3_value **argv,
+  sqlite_int64 *pRowid
+){
+  amatch_vtab *p = (amatch_vtab*)pVTab;
+  const unsigned char *zCmd;
+  (void)pRowid;
+  if( argc==1 ){
+    pVTab->zErrMsg = sqlite3_mprintf("DELETE from %s is not allowed", 
+                                      p->zSelf);
+    return SQLITE_ERROR;
+  }
+  if( sqlite3_value_type(argv[0])!=SQLITE_NULL ){
+    pVTab->zErrMsg = sqlite3_mprintf("UPDATE of %s is not allowed", 
+                                      p->zSelf);
+    return SQLITE_ERROR;
+  }
+  if( sqlite3_value_type(argv[2+AMATCH_COL_WORD])!=SQLITE_NULL
+   || sqlite3_value_type(argv[2+AMATCH_COL_DISTANCE])!=SQLITE_NULL
+   || sqlite3_value_type(argv[2+AMATCH_COL_LANGUAGE])!=SQLITE_NULL
+  ){
+    pVTab->zErrMsg = sqlite3_mprintf(
+            "INSERT INTO %s allowed for column [command] only", p->zSelf);
+    return SQLITE_ERROR;
+  }
+  zCmd = sqlite3_value_text(argv[2+AMATCH_COL_COMMAND]);
+  if( zCmd==0 ) return SQLITE_OK;
+  
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that implements the "approximate_match".
+*/
+static sqlite3_module amatchModule = {
+  0,                      /* iVersion */
+  amatchConnect,          /* xCreate */
+  amatchConnect,          /* xConnect */
+  amatchBestIndex,        /* xBestIndex */
+  amatchDisconnect,       /* xDisconnect */
+  amatchDisconnect,       /* xDestroy */
+  amatchOpen,             /* xOpen - open a cursor */
+  amatchClose,            /* xClose - close a cursor */
+  amatchFilter,           /* xFilter - configure scan constraints */
+  amatchNext,             /* xNext - advance a cursor */
+  amatchEof,              /* xEof - check for end of scan */
+  amatchColumn,           /* xColumn - read data */
+  amatchRowid,            /* xRowid - read data */
+  amatchUpdate,           /* xUpdate */
+  0,                      /* xBegin */
+  0,                      /* xSync */
+  0,                      /* xCommit */
+  0,                      /* xRollback */
+  0,                      /* xFindMethod */
+  0,                      /* xRename */
+  0,                      /* xSavepoint */
+  0,                      /* xRelease */
+  0                       /* xRollbackTo */
+};
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Register the amatch virtual table
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_amatch_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Not used */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  rc = sqlite3_create_module(db, "approximate_match", &amatchModule, 0);
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/closure.c b/lib/libsqlite3/ext/misc/closure.c
new file mode 100644
index 00000000000..213b7633e68
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/closure.c
@@ -0,0 +1,948 @@
+/*
+** 2013-04-16
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code for a virtual table that finds the transitive
+** closure of a parent/child relationship in a real table.  The virtual 
+** table is called "transitive_closure".
+**
+** A transitive_closure virtual table is created like this:
+**
+**     CREATE VIRTUAL TABLE x USING transitive_closure(
+**        tablename=<tablename>,      -- T
+**        idcolumn=<columnname>,      -- X
+**        parentcolumn=<columnname>   -- P
+**     );
+**
+** When it is created, the new transitive_closure table may be supplied 
+** with default values for the name of a table T and columns T.X and T.P.
+** The T.X and T.P columns must contain integers.  The ideal case is for 
+** T.X to be the INTEGER PRIMARY KEY.  The T.P column should reference
+** the T.X column. The row referenced by T.P is the parent of the current row.
+**
+** The tablename, idcolumn, and parentcolumn supplied by the CREATE VIRTUAL
+** TABLE statement may be overridden in individual queries by including
+** terms like tablename='newtable', idcolumn='id2', or 
+** parentcolumn='parent3' in the WHERE clause of the query.
+**
+** For efficiency, it is essential that there be an index on the P column:
+**
+**    CREATE Tidx1 ON T(P)
+**
+** Suppose a specific instance of the closure table is as follows:
+**
+**    CREATE VIRTUAL TABLE ct1 USING transitive_closure(
+**       tablename='group',
+**       idcolumn='groupId',
+**       parentcolumn='parentId'
+**    );
+**
+** Such an instance of the transitive_closure virtual table would be
+** appropriate for walking a tree defined using a table like this, for example:
+**
+**    CREATE TABLE group(
+**      groupId INTEGER PRIMARY KEY,
+**      parentId INTEGER REFERENCES group
+**    );
+**    CREATE INDEX group_idx1 ON group(parentId);
+**
+** The group table above would presumably have other application-specific
+** fields.  The key point here is that rows of the group table form a
+** tree.  The purpose of the ct1 virtual table is to easily extract
+** branches of that tree.
+**
+** Once it has been created, the ct1 virtual table can be queried
+** as follows:
+**
+**    SELECT * FROM element
+**     WHERE element.groupId IN (SELECT id FROM ct1 WHERE root=?1);
+**
+** The above query will return all elements that are part of group ?1
+** or children of group ?1 or grand-children of ?1 and so forth for all
+** descendents of group ?1.  The same query can be formulated as a join:
+**
+**    SELECT element.* FROM element, ct1
+**     WHERE element.groupid=ct1.id
+**       AND ct1.root=?1;
+**
+** The depth of the transitive_closure (the number of generations of
+** parent/child relations to follow) can be limited by setting "depth"
+** column in the WHERE clause.  So, for example, the following query
+** finds only children and grandchildren but no further descendents:
+**
+**    SELECT element.* FROM element, ct1
+**     WHERE element.groupid=ct1.id
+**       AND ct1.root=?1
+**       AND ct1.depth<=2;
+**
+** The "ct1.depth<=2" term could be a strict equality "ct1.depth=2" in
+** order to find only the grandchildren of ?1, not ?1 itself or the
+** children of ?1.
+** 
+** The root=?1 term must be supplied in WHERE clause or else the query
+** of the ct1 virtual table will return an empty set.  The tablename,
+** idcolumn, and parentcolumn attributes can be overridden in the WHERE
+** clause if desired.  So, for example, the ct1 table could be repurposed
+** to find ancestors rather than descendents by inverting the roles of
+** the idcolumn and parentcolumn:
+**
+**    SELECT element.* FROM element, ct1
+**     WHERE element.groupid=ct1.id
+**       AND ct1.root=?1
+**       AND ct1.idcolumn='parentId'
+**       AND ct1.parentcolumn='groupId';
+**
+** Multiple calls to ct1 could be combined.  For example, the following
+** query finds all elements that "cousins" of groupId ?1.  That is to say
+** elements where the groupId is a grandchild of the grandparent of ?1.
+** (This definition of "cousins" also includes siblings and self.)
+**
+**    SELECT element.* FROM element, ct1
+**     WHERE element.groupId=ct1.id
+**       AND ct1.depth=2
+**       AND ct1.root IN (SELECT id FROM ct1
+**                         WHERE root=?1
+**                           AND depth=2
+**                           AND idcolumn='parentId'
+**                           AND parentcolumn='groupId');
+**
+** In our example, the group.groupId column is unique and thus the
+** subquery will return exactly one row.  For that reason, the IN
+** operator could be replaced by "=" to get the same result.  But
+** in the general case where the idcolumn is not unique, an IN operator
+** would be required for this kind of query.
+**
+** Note that because the tablename, idcolumn, and parentcolumn can
+** all be specified in the query, it is possible for an application
+** to define a single transitive_closure virtual table for use on lots
+** of different hierarchy tables.  One might say:
+**
+**     CREATE VIRTUAL TABLE temp.closure USING transitive_closure;
+**
+** As each database connection is being opened.  Then the application
+** would always have a "closure" virtual table handy to use for querying.
+**
+**    SELECT element.* FROM element, closure
+**     WHERE element.groupid=ct1.id
+**       AND closure.root=?1
+**       AND closure.tablename='group'
+**       AND closure.idname='groupId'
+**       AND closure.parentname='parentId';
+**
+** See the documentation at http://www.sqlite.org/loadext.html for information
+** on how to compile and use loadable extensions such as this one.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Forward declaration of objects used by this implementation
+*/
+typedef struct closure_vtab closure_vtab;
+typedef struct closure_cursor closure_cursor;
+typedef struct closure_queue closure_queue;
+typedef struct closure_avl closure_avl;
+
+/*****************************************************************************
+** AVL Tree implementation
+*/
+/*
+** Objects that want to be members of the AVL tree should embedded an
+** instance of this structure.
+*/
+struct closure_avl {
+  sqlite3_int64 id;     /* Id of this entry in the table */
+  int iGeneration;      /* Which generation is this entry part of */
+  closure_avl *pList;   /* A linked list of nodes */
+  closure_avl *pBefore; /* Other elements less than id */
+  closure_avl *pAfter;  /* Other elements greater than id */
+  closure_avl *pUp;     /* Parent element */
+  short int height;     /* Height of this node.  Leaf==1 */
+  short int imbalance;  /* Height difference between pBefore and pAfter */
+};
+
+/* Recompute the closure_avl.height and closure_avl.imbalance fields for p.
+** Assume that the children of p have correct heights.
+*/
+static void closureAvlRecomputeHeight(closure_avl *p){
+  short int hBefore = p->pBefore ? p->pBefore->height : 0;
+  short int hAfter = p->pAfter ? p->pAfter->height : 0;
+  p->imbalance = hBefore - hAfter;  /* -: pAfter higher.  +: pBefore higher */
+  p->height = (hBefore>hAfter ? hBefore : hAfter)+1;
+}
+
+/*
+**     P                B
+**    / \              / \
+**   B   Z    ==>     X   P
+**  / \                  / \
+** X   Y                Y   Z
+**
+*/
+static closure_avl *closureAvlRotateBefore(closure_avl *pP){
+  closure_avl *pB = pP->pBefore;
+  closure_avl *pY = pB->pAfter;
+  pB->pUp = pP->pUp;
+  pB->pAfter = pP;
+  pP->pUp = pB;
+  pP->pBefore = pY;
+  if( pY ) pY->pUp = pP;
+  closureAvlRecomputeHeight(pP);
+  closureAvlRecomputeHeight(pB);
+  return pB;
+}
+
+/*
+**     P                A
+**    / \              / \
+**   X   A    ==>     P   Z
+**      / \          / \
+**     Y   Z        X   Y
+**
+*/
+static closure_avl *closureAvlRotateAfter(closure_avl *pP){
+  closure_avl *pA = pP->pAfter;
+  closure_avl *pY = pA->pBefore;
+  pA->pUp = pP->pUp;
+  pA->pBefore = pP;
+  pP->pUp = pA;
+  pP->pAfter = pY;
+  if( pY ) pY->pUp = pP;
+  closureAvlRecomputeHeight(pP);
+  closureAvlRecomputeHeight(pA);
+  return pA;
+}
+
+/*
+** Return a pointer to the pBefore or pAfter pointer in the parent
+** of p that points to p.  Or if p is the root node, return pp.
+*/
+static closure_avl **closureAvlFromPtr(closure_avl *p, closure_avl **pp){
+  closure_avl *pUp = p->pUp;
+  if( pUp==0 ) return pp;
+  if( pUp->pAfter==p ) return &pUp->pAfter;
+  return &pUp->pBefore;
+}
+
+/*
+** Rebalance all nodes starting with p and working up to the root.
+** Return the new root.
+*/
+static closure_avl *closureAvlBalance(closure_avl *p){
+  closure_avl *pTop = p;
+  closure_avl **pp;
+  while( p ){
+    closureAvlRecomputeHeight(p);
+    if( p->imbalance>=2 ){
+      closure_avl *pB = p->pBefore;
+      if( pB->imbalance<0 ) p->pBefore = closureAvlRotateAfter(pB);
+      pp = closureAvlFromPtr(p,&p);
+      p = *pp = closureAvlRotateBefore(p);
+    }else if( p->imbalance<=(-2) ){
+      closure_avl *pA = p->pAfter;
+      if( pA->imbalance>0 ) p->pAfter = closureAvlRotateBefore(pA);
+      pp = closureAvlFromPtr(p,&p);
+      p = *pp = closureAvlRotateAfter(p);
+    }
+    pTop = p;
+    p = p->pUp;
+  }
+  return pTop;
+}
+
+/* Search the tree rooted at p for an entry with id.  Return a pointer
+** to the entry or return NULL.
+*/
+static closure_avl *closureAvlSearch(closure_avl *p, sqlite3_int64 id){
+  while( p && id!=p->id ){
+    p = (id<p->id) ? p->pBefore : p->pAfter;
+  }
+  return p;
+}
+
+/* Find the first node (the one with the smallest key).
+*/
+static closure_avl *closureAvlFirst(closure_avl *p){
+  if( p ) while( p->pBefore ) p = p->pBefore;
+  return p;
+}
+
+/* Return the node with the next larger key after p.
+*/
+closure_avl *closureAvlNext(closure_avl *p){
+  closure_avl *pPrev = 0;
+  while( p && p->pAfter==pPrev ){
+    pPrev = p;
+    p = p->pUp;
+  }
+  if( p && pPrev==0 ){
+    p = closureAvlFirst(p->pAfter);
+  }
+  return p;
+}
+
+/* Insert a new node pNew.  Return NULL on success.  If the key is not
+** unique, then do not perform the insert but instead leave pNew unchanged
+** and return a pointer to an existing node with the same key.
+*/
+static closure_avl *closureAvlInsert(
+  closure_avl **ppHead,  /* Head of the tree */
+  closure_avl *pNew      /* New node to be inserted */
+){
+  closure_avl *p = *ppHead;
+  if( p==0 ){
+    p = pNew;
+    pNew->pUp = 0;
+  }else{
+    while( p ){
+      if( pNew->id<p->id ){
+        if( p->pBefore ){
+          p = p->pBefore;
+        }else{
+          p->pBefore = pNew;
+          pNew->pUp = p;
+          break;
+        }
+      }else if( pNew->id>p->id ){
+        if( p->pAfter ){
+          p = p->pAfter;
+        }else{
+          p->pAfter = pNew;
+          pNew->pUp = p;
+          break;
+        }
+      }else{
+        return p;
+      }
+    }
+  }
+  pNew->pBefore = 0;
+  pNew->pAfter = 0;
+  pNew->height = 1;
+  pNew->imbalance = 0;
+  *ppHead = closureAvlBalance(p);
+  return 0;
+}
+
+/* Walk the tree can call xDestroy on each node
+*/
+static void closureAvlDestroy(closure_avl *p, void (*xDestroy)(closure_avl*)){
+  if( p ){
+    closureAvlDestroy(p->pBefore, xDestroy);
+    closureAvlDestroy(p->pAfter, xDestroy);
+    xDestroy(p);
+  }
+}
+/*
+** End of the AVL Tree implementation
+******************************************************************************/
+
+/* 
+** A closure virtual-table object 
+*/
+struct closure_vtab {
+  sqlite3_vtab base;         /* Base class - must be first */
+  char *zDb;                 /* Name of database.  (ex: "main") */
+  char *zSelf;               /* Name of this virtual table */
+  char *zTableName;          /* Name of table holding parent/child relation */
+  char *zIdColumn;           /* Name of ID column of zTableName */
+  char *zParentColumn;       /* Name of PARENT column in zTableName */
+  sqlite3 *db;               /* The database connection */
+  int nCursor;               /* Number of pending cursors */
+};
+
+/* A closure cursor object */
+struct closure_cursor {
+  sqlite3_vtab_cursor base;  /* Base class - must be first */
+  closure_vtab *pVtab;       /* The virtual table this cursor belongs to */
+  char *zTableName;          /* Name of table holding parent/child relation */
+  char *zIdColumn;           /* Name of ID column of zTableName */
+  char *zParentColumn;       /* Name of PARENT column in zTableName */
+  closure_avl *pCurrent;     /* Current element of output */
+  closure_avl *pClosure;     /* The complete closure tree */
+};
+
+/* A queue of AVL nodes */
+struct closure_queue {
+  closure_avl *pFirst;       /* Oldest node on the queue */
+  closure_avl *pLast;        /* Youngest node on the queue */
+};
+
+/*
+** Add a node to the end of the queue
+*/
+static void queuePush(closure_queue *pQueue, closure_avl *pNode){
+  pNode->pList = 0;
+  if( pQueue->pLast ){
+    pQueue->pLast->pList = pNode;
+  }else{
+    pQueue->pFirst = pNode;
+  }
+  pQueue->pLast = pNode;
+}
+
+/*
+** Extract the oldest element (the front element) from the queue.
+*/
+static closure_avl *queuePull(closure_queue *pQueue){
+  closure_avl *p = pQueue->pFirst;
+  if( p ){
+    pQueue->pFirst = p->pList;
+    if( pQueue->pFirst==0 ) pQueue->pLast = 0;
+  }
+  return p;
+}
+
+/*
+** This function converts an SQL quoted string into an unquoted string
+** and returns a pointer to a buffer allocated using sqlite3_malloc() 
+** containing the result. The caller should eventually free this buffer
+** using sqlite3_free.
+**
+** Examples:
+**
+**     "abc"   becomes   abc
+**     'xyz'   becomes   xyz
+**     [pqr]   becomes   pqr
+**     `mno`   becomes   mno
+*/
+static char *closureDequote(const char *zIn){
+  int nIn;                        /* Size of input string, in bytes */
+  char *zOut;                     /* Output (dequoted) string */
+
+  nIn = (int)strlen(zIn);
+  zOut = sqlite3_malloc(nIn+1);
+  if( zOut ){
+    char q = zIn[0];              /* Quote character (if any ) */
+
+    if( q!='[' && q!= '\'' && q!='"' && q!='`' ){
+      memcpy(zOut, zIn, nIn+1);
+    }else{
+      int iOut = 0;               /* Index of next byte to write to output */
+      int iIn;                    /* Index of next byte to read from input */
+
+      if( q=='[' ) q = ']';
+      for(iIn=1; iIn<nIn; iIn++){
+        if( zIn[iIn]==q ) iIn++;
+        zOut[iOut++] = zIn[iIn];
+      }
+    }
+    assert( (int)strlen(zOut)<=nIn );
+  }
+  return zOut;
+}
+
+/*
+** Deallocate an closure_vtab object
+*/
+static void closureFree(closure_vtab *p){
+  if( p ){
+    sqlite3_free(p->zDb);
+    sqlite3_free(p->zSelf);
+    sqlite3_free(p->zTableName);
+    sqlite3_free(p->zIdColumn);
+    sqlite3_free(p->zParentColumn);
+    memset(p, 0, sizeof(*p));
+    sqlite3_free(p);
+  }
+}
+
+/*
+** xDisconnect/xDestroy method for the closure module.
+*/
+static int closureDisconnect(sqlite3_vtab *pVtab){
+  closure_vtab *p = (closure_vtab*)pVtab;
+  assert( p->nCursor==0 );
+  closureFree(p);
+  return SQLITE_OK;
+}
+
+/*
+** Check to see if the argument is of the form:
+**
+**       KEY = VALUE
+**
+** If it is, return a pointer to the first character of VALUE.
+** If not, return NULL.  Spaces around the = are ignored.
+*/
+static const char *closureValueOfKey(const char *zKey, const char *zStr){
+  int nKey = (int)strlen(zKey);
+  int nStr = (int)strlen(zStr);
+  int i;
+  if( nStr<nKey+1 ) return 0;
+  if( memcmp(zStr, zKey, nKey)!=0 ) return 0;
+  for(i=nKey; isspace(zStr[i]); i++){}
+  if( zStr[i]!='=' ) return 0;
+  i++;
+  while( isspace(zStr[i]) ){ i++; }
+  return zStr+i;
+}
+
+/*
+** xConnect/xCreate method for the closure module. Arguments are:
+**
+**   argv[0]    -> module name  ("approximate_match")
+**   argv[1]    -> database name
+**   argv[2]    -> table name
+**   argv[3...] -> arguments
+*/
+static int closureConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc = SQLITE_OK;              /* Return code */
+  closure_vtab *pNew = 0;          /* New virtual table */
+  const char *zDb = argv[1];
+  const char *zVal;
+  int i;
+
+  (void)pAux;
+  *ppVtab = 0;
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  if( pNew==0 ) return SQLITE_NOMEM;
+  rc = SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  pNew->db = db;
+  pNew->zDb = sqlite3_mprintf("%s", zDb);
+  if( pNew->zDb==0 ) goto closureConnectError;
+  pNew->zSelf = sqlite3_mprintf("%s", argv[2]);
+  if( pNew->zSelf==0 ) goto closureConnectError;
+  for(i=3; i<argc; i++){
+    zVal = closureValueOfKey("tablename", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zTableName);
+      pNew->zTableName = closureDequote(zVal);
+      if( pNew->zTableName==0 ) goto closureConnectError;
+      continue;
+    }
+    zVal = closureValueOfKey("idcolumn", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zIdColumn);
+      pNew->zIdColumn = closureDequote(zVal);
+      if( pNew->zIdColumn==0 ) goto closureConnectError;
+      continue;
+    }
+    zVal = closureValueOfKey("parentcolumn", argv[i]);
+    if( zVal ){
+      sqlite3_free(pNew->zParentColumn);
+      pNew->zParentColumn = closureDequote(zVal);
+      if( pNew->zParentColumn==0 ) goto closureConnectError;
+      continue;
+    }
+    *pzErr = sqlite3_mprintf("unrecognized argument: [%s]\n", argv[i]);
+    closureFree(pNew);
+    *ppVtab = 0;
+    return SQLITE_ERROR;
+  }
+  rc = sqlite3_declare_vtab(db,
+         "CREATE TABLE x(id,depth,root HIDDEN,tablename HIDDEN,"
+                        "idcolumn HIDDEN,parentcolumn HIDDEN)"
+       );
+#define CLOSURE_COL_ID              0
+#define CLOSURE_COL_DEPTH           1
+#define CLOSURE_COL_ROOT            2
+#define CLOSURE_COL_TABLENAME       3
+#define CLOSURE_COL_IDCOLUMN        4
+#define CLOSURE_COL_PARENTCOLUMN    5
+  if( rc!=SQLITE_OK ){
+    closureFree(pNew);
+  }
+  *ppVtab = &pNew->base;
+  return rc;
+
+closureConnectError:
+  closureFree(pNew);
+  return rc;
+}
+
+/*
+** Open a new closure cursor.
+*/
+static int closureOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  closure_vtab *p = (closure_vtab*)pVTab;
+  closure_cursor *pCur;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  pCur->pVtab = p;
+  *ppCursor = &pCur->base;
+  p->nCursor++;
+  return SQLITE_OK;
+}
+
+/*
+** Free up all the memory allocated by a cursor.  Set it rLimit to 0
+** to indicate that it is at EOF.
+*/
+static void closureClearCursor(closure_cursor *pCur){
+  closureAvlDestroy(pCur->pClosure, (void(*)(closure_avl*))sqlite3_free);
+  sqlite3_free(pCur->zTableName);
+  sqlite3_free(pCur->zIdColumn);
+  sqlite3_free(pCur->zParentColumn);
+  pCur->zTableName = 0;
+  pCur->zIdColumn = 0;
+  pCur->zParentColumn = 0;
+  pCur->pCurrent = 0;
+  pCur->pClosure = 0;
+}
+
+/*
+** Close a closure cursor.
+*/
+static int closureClose(sqlite3_vtab_cursor *cur){
+  closure_cursor *pCur = (closure_cursor *)cur;
+  closureClearCursor(pCur);
+  pCur->pVtab->nCursor--;
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Advance a cursor to its next row of output
+*/
+static int closureNext(sqlite3_vtab_cursor *cur){
+  closure_cursor *pCur = (closure_cursor*)cur;
+  pCur->pCurrent = closureAvlNext(pCur->pCurrent);
+  return SQLITE_OK;
+}
+
+/*
+** Allocate and insert a node
+*/
+static int closureInsertNode(
+  closure_queue *pQueue,  /* Add new node to this queue */
+  closure_cursor *pCur,   /* The cursor into which to add the node */
+  sqlite3_int64 id,       /* The node ID */
+  int iGeneration         /* The generation number for this node */
+){
+  closure_avl *pNew = sqlite3_malloc( sizeof(*pNew) );
+  if( pNew==0 ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  pNew->id = id;
+  pNew->iGeneration = iGeneration;
+  closureAvlInsert(&pCur->pClosure, pNew);
+  queuePush(pQueue, pNew);
+  return SQLITE_OK;
+}
+
+/*
+** Called to "rewind" a cursor back to the beginning so that
+** it starts its output over again.  Always called at least once
+** prior to any closureColumn, closureRowid, or closureEof call.
+**
+** This routine actually computes the closure.
+**
+** See the comment at the beginning of closureBestIndex() for a 
+** description of the meaning of idxNum.  The idxStr parameter is
+** not used.
+*/
+static int closureFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  closure_cursor *pCur = (closure_cursor *)pVtabCursor;
+  closure_vtab *pVtab = pCur->pVtab;
+  sqlite3_int64 iRoot;
+  int mxGen = 999999999;
+  char *zSql;
+  sqlite3_stmt *pStmt;
+  closure_avl *pAvl;
+  int rc = SQLITE_OK;
+  const char *zTableName = pVtab->zTableName;
+  const char *zIdColumn = pVtab->zIdColumn;
+  const char *zParentColumn = pVtab->zParentColumn;
+  closure_queue sQueue;
+
+  (void)idxStr;  /* Unused parameter */
+  (void)argc;    /* Unused parameter */
+  closureClearCursor(pCur);
+  memset(&sQueue, 0, sizeof(sQueue));
+  if( (idxNum & 1)==0 ){
+    /* No root=$root in the WHERE clause.  Return an empty set */
+    return SQLITE_OK;
+  }
+  iRoot = sqlite3_value_int64(argv[0]);
+  if( (idxNum & 0x000f0)!=0 ){
+    mxGen = sqlite3_value_int(argv[(idxNum>>4)&0x0f]);
+    if( (idxNum & 0x00002)!=0 ) mxGen--;
+  }
+  if( (idxNum & 0x00f00)!=0 ){
+    zTableName = (const char*)sqlite3_value_text(argv[(idxNum>>8)&0x0f]);
+    pCur->zTableName = sqlite3_mprintf("%s", zTableName);
+  }
+  if( (idxNum & 0x0f000)!=0 ){
+    zIdColumn = (const char*)sqlite3_value_text(argv[(idxNum>>12)&0x0f]);
+    pCur->zIdColumn = sqlite3_mprintf("%s", zIdColumn);
+  }
+  if( (idxNum & 0x0f0000)!=0 ){
+    zParentColumn = (const char*)sqlite3_value_text(argv[(idxNum>>16)&0x0f]);
+    pCur->zParentColumn = sqlite3_mprintf("%s", zParentColumn);
+  }
+
+  zSql = sqlite3_mprintf(
+       "SELECT \"%w\".\"%w\" FROM \"%w\" WHERE \"%w\".\"%w\"=?1",
+       zTableName, zIdColumn, zTableName, zTableName, zParentColumn);
+  if( zSql==0 ){
+    return SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_prepare_v2(pVtab->db, zSql, -1, &pStmt, 0);
+    sqlite3_free(zSql);
+    if( rc ){
+      sqlite3_free(pVtab->base.zErrMsg);
+      pVtab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pVtab->db));
+      return rc;
+    }
+  }
+  if( rc==SQLITE_OK ){
+    rc = closureInsertNode(&sQueue, pCur, iRoot, 0);
+  }
+  while( (pAvl = queuePull(&sQueue))!=0 ){
+    if( pAvl->iGeneration>=mxGen ) continue;
+    sqlite3_bind_int64(pStmt, 1, pAvl->id);
+    while( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
+      if( sqlite3_column_type(pStmt,0)==SQLITE_INTEGER ){
+        sqlite3_int64 iNew = sqlite3_column_int64(pStmt, 0);
+        if( closureAvlSearch(pCur->pClosure, iNew)==0 ){
+          rc = closureInsertNode(&sQueue, pCur, iNew, pAvl->iGeneration+1);
+        }
+      }
+    }
+    sqlite3_reset(pStmt);
+  }
+  sqlite3_finalize(pStmt);
+  if( rc==SQLITE_OK ){
+    pCur->pCurrent = closureAvlFirst(pCur->pClosure);
+  }
+
+  return rc;
+}
+
+/*
+** Only the word and distance columns have values.  All other columns
+** return NULL
+*/
+static int closureColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  closure_cursor *pCur = (closure_cursor*)cur;
+  switch( i ){
+    case CLOSURE_COL_ID: {
+      sqlite3_result_int64(ctx, pCur->pCurrent->id);
+      break;
+    }
+    case CLOSURE_COL_DEPTH: {
+      sqlite3_result_int(ctx, pCur->pCurrent->iGeneration);
+      break;
+    }
+    case CLOSURE_COL_ROOT: {
+      sqlite3_result_null(ctx);
+      break;
+    }
+    case CLOSURE_COL_TABLENAME: {
+      sqlite3_result_text(ctx,
+         pCur->zTableName ? pCur->zTableName : pCur->pVtab->zTableName,
+         -1, SQLITE_TRANSIENT);
+      break;
+    }
+    case CLOSURE_COL_IDCOLUMN: {
+      sqlite3_result_text(ctx,
+         pCur->zIdColumn ? pCur->zIdColumn : pCur->pVtab->zIdColumn,
+         -1, SQLITE_TRANSIENT);
+      break;
+    }
+    case CLOSURE_COL_PARENTCOLUMN: {
+      sqlite3_result_text(ctx,
+         pCur->zParentColumn ? pCur->zParentColumn : pCur->pVtab->zParentColumn,
+         -1, SQLITE_TRANSIENT);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The rowid.  For the closure table, this is the same as the "id" column.
+*/
+static int closureRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  closure_cursor *pCur = (closure_cursor*)cur;
+  *pRowid = pCur->pCurrent->id;
+  return SQLITE_OK;
+}
+
+/*
+** EOF indicator
+*/
+static int closureEof(sqlite3_vtab_cursor *cur){
+  closure_cursor *pCur = (closure_cursor*)cur;
+  return pCur->pCurrent==0;
+}
+
+/*
+** Search for terms of these forms:
+**
+**   (A)    root = $root
+**   (B1)   depth < $depth
+**   (B2)   depth <= $depth
+**   (B3)   depth = $depth
+**   (C)    tablename = $tablename
+**   (D)    idcolumn = $idcolumn
+**   (E)    parentcolumn = $parentcolumn
+**
+** 
+**
+**   idxNum       meaning
+**   ----------   ------------------------------------------------------
+**   0x00000001   Term of the form (A) found
+**   0x00000002   The term of bit-2 is like (B1)
+**   0x000000f0   Index in filter.argv[] of $depth.  0 if not used.
+**   0x00000f00   Index in filter.argv[] of $tablename.  0 if not used.
+**   0x0000f000   Index in filter.argv[] of $idcolumn.  0 if not used
+**   0x000f0000   Index in filter.argv[] of $parentcolumn.  0 if not used.
+**
+** There must be a term of type (A).  If there is not, then the index type
+** is 0 and the query will return an empty set.
+*/
+static int closureBestIndex(
+  sqlite3_vtab *pTab,             /* The virtual table */
+  sqlite3_index_info *pIdxInfo    /* Information about the query */
+){
+  int iPlan = 0;
+  int i;
+  int idx = 1;
+  const struct sqlite3_index_constraint *pConstraint;
+  closure_vtab *pVtab = (closure_vtab*)pTab;
+
+  pConstraint = pIdxInfo->aConstraint;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( (iPlan & 1)==0 
+     && pConstraint->iColumn==CLOSURE_COL_ROOT
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 1;
+      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+    if( (iPlan & 0x0000f0)==0
+     && pConstraint->iColumn==CLOSURE_COL_DEPTH
+     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
+           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE
+           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ)
+    ){
+      iPlan |= idx<<4;
+      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
+      if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ) iPlan |= 0x000002;
+    }
+    if( (iPlan & 0x000f00)==0
+     && pConstraint->iColumn==CLOSURE_COL_TABLENAME
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= idx<<8;
+      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+    if( (iPlan & 0x00f000)==0
+     && pConstraint->iColumn==CLOSURE_COL_IDCOLUMN
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= idx<<12;
+      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+    if( (iPlan & 0x0f0000)==0
+     && pConstraint->iColumn==CLOSURE_COL_PARENTCOLUMN
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= idx<<16;
+      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+  }
+  if( (pVtab->zTableName==0    && (iPlan & 0x000f00)==0)
+   || (pVtab->zIdColumn==0     && (iPlan & 0x00f000)==0)
+   || (pVtab->zParentColumn==0 && (iPlan & 0x0f0000)==0)
+  ){
+    /* All of tablename, idcolumn, and parentcolumn must be specified
+    ** in either the CREATE VIRTUAL TABLE or in the WHERE clause constraints
+    ** or else the result is an empty set. */
+    iPlan = 0;
+  }
+  pIdxInfo->idxNum = iPlan;
+  if( pIdxInfo->nOrderBy==1
+   && pIdxInfo->aOrderBy[0].iColumn==CLOSURE_COL_ID
+   && pIdxInfo->aOrderBy[0].desc==0
+  ){
+    pIdxInfo->orderByConsumed = 1;
+  }
+  pIdxInfo->estimatedCost = (double)10000;
+   
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that implements the "approximate_match".
+*/
+static sqlite3_module closureModule = {
+  0,                      /* iVersion */
+  closureConnect,         /* xCreate */
+  closureConnect,         /* xConnect */
+  closureBestIndex,       /* xBestIndex */
+  closureDisconnect,      /* xDisconnect */
+  closureDisconnect,      /* xDestroy */
+  closureOpen,            /* xOpen - open a cursor */
+  closureClose,           /* xClose - close a cursor */
+  closureFilter,          /* xFilter - configure scan constraints */
+  closureNext,            /* xNext - advance a cursor */
+  closureEof,             /* xEof - check for end of scan */
+  closureColumn,          /* xColumn - read data */
+  closureRowid,           /* xRowid - read data */
+  0,                      /* xUpdate */
+  0,                      /* xBegin */
+  0,                      /* xSync */
+  0,                      /* xCommit */
+  0,                      /* xRollback */
+  0,                      /* xFindMethod */
+  0,                      /* xRename */
+  0,                      /* xSavepoint */
+  0,                      /* xRelease */
+  0                       /* xRollbackTo */
+};
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Register the closure virtual table
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_closure_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  rc = sqlite3_create_module(db, "transitive_closure", &closureModule, 0);
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/fuzzer.c b/lib/libsqlite3/ext/misc/fuzzer.c
new file mode 100644
index 00000000000..642b8f9e92d
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/fuzzer.c
@@ -0,0 +1,1173 @@
+/*
+** 2011 March 24
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** Code for a demonstration virtual table that generates variations
+** on an input word at increasing edit distances from the original.
+**
+** A fuzzer virtual table is created like this:
+**
+**     CREATE VIRTUAL TABLE f USING fuzzer(<fuzzer-data-table>);
+**
+** When it is created, the new fuzzer table must be supplied with the
+** name of a "fuzzer data table", which must reside in the same database
+** file as the new fuzzer table. The fuzzer data table contains the various
+** transformations and their costs that the fuzzer logic uses to generate
+** variations.
+**
+** The fuzzer data table must contain exactly four columns (more precisely,
+** the statement "SELECT * FROM <fuzzer_data_table>" must return records
+** that consist of four columns). It does not matter what the columns are
+** named. 
+**
+** Each row in the fuzzer data table represents a single character
+** transformation. The left most column of the row (column 0) contains an
+** integer value - the identifier of the ruleset to which the transformation
+** rule belongs (see "MULTIPLE RULE SETS" below). The second column of the
+** row (column 0) contains the input character or characters. The third 
+** column contains the output character or characters. And the fourth column
+** contains the integer cost of making the transformation. For example:
+**
+**    CREATE TABLE f_data(ruleset, cFrom, cTo, Cost);
+**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, '', 'a', 100);
+**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, 'b', '', 87);
+**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, 'o', 'oe', 38);
+**    INSERT INTO f_data(ruleset, cFrom, cTo, Cost) VALUES(0, 'oe', 'o', 40);
+**
+** The first row inserted into the fuzzer data table by the SQL script
+** above indicates that the cost of inserting a letter 'a' is 100.  (All 
+** costs are integers.  We recommend that costs be scaled so that the 
+** average cost is around 100.) The second INSERT statement creates a rule
+** saying that the cost of deleting a single letter 'b' is 87.  The third
+** and fourth INSERT statements mean that the cost of transforming a
+** single letter "o" into the two-letter sequence "oe" is 38 and that the
+** cost of transforming "oe" back into "o" is 40.
+**
+** The contents of the fuzzer data table are loaded into main memory when
+** a fuzzer table is first created, and may be internally reloaded by the
+** system at any subsequent time. Therefore, the fuzzer data table should be 
+** populated before the fuzzer table is created and not modified thereafter.
+** If you do need to modify the contents of the fuzzer data table, it is
+** recommended that the associated fuzzer table be dropped, the fuzzer data
+** table edited, and the fuzzer table recreated within a single transaction.
+** Alternatively, the fuzzer data table can be edited then the database
+** connection can be closed and reopened.
+**
+** Once it has been created, the fuzzer table can be queried as follows:
+**
+**    SELECT word, distance FROM f
+**     WHERE word MATCH 'abcdefg'
+**       AND distance<200;
+**
+** This first query outputs the string "abcdefg" and all strings that
+** can be derived from that string by appling the specified transformations.
+** The strings are output together with their total transformation cost
+** (called "distance") and appear in order of increasing cost.  No string
+** is output more than once.  If there are multiple ways to transform the
+** target string into the output string then the lowest cost transform is
+** the one that is returned.  In the example, the search is limited to 
+** strings with a total distance of less than 200.
+**
+** The fuzzer is a read-only table.  Any attempt to DELETE, INSERT, or
+** UPDATE on a fuzzer table will throw an error.
+**
+** It is important to put some kind of a limit on the fuzzer output.  This
+** can be either in the form of a LIMIT clause at the end of the query,
+** or better, a "distance<NNN" constraint where NNN is some number.  The
+** running time and memory requirement is exponential in the value of NNN 
+** so you want to make sure that NNN is not too big.  A value of NNN that
+** is about twice the average transformation cost seems to give good results.
+**
+** The fuzzer table can be useful for tasks such as spelling correction.
+** Suppose there is a second table vocabulary(w) where the w column contains
+** all correctly spelled words.   Let $word be a word you want to look up.
+**
+**   SELECT vocabulary.w FROM f, vocabulary
+**    WHERE f.word MATCH $word
+**      AND f.distance<=200
+**      AND f.word=vocabulary.w
+**    LIMIT 20
+**
+** The query above gives the 20 closest words to the $word being tested.
+** (Note that for good performance, the vocubulary.w column should be
+** indexed.)
+**
+** A similar query can be used to find all words in the dictionary that
+** begin with some prefix $prefix:
+**
+**   SELECT vocabulary.w FROM f, vocabulary
+**    WHERE f.word MATCH $prefix
+**      AND f.distance<=200
+**      AND vocabulary.w BETWEEN f.word AND (f.word || x'F7BFBFBF')
+**    LIMIT 50
+**
+** This last query will show up to 50 words out of the vocabulary that
+** match or nearly match the $prefix.
+**
+** MULTIPLE RULE SETS
+**
+** Normally, the "ruleset" value associated with all character transformations
+** in the fuzzer data table is zero. However, if required, the fuzzer table
+** allows multiple rulesets to be defined. Each query uses only a single
+** ruleset. This allows, for example, a single fuzzer table to support 
+** multiple languages.
+**
+** By default, only the rules from ruleset 0 are used. To specify an 
+** alternative ruleset, a "ruleset = ?" expression must be added to the
+** WHERE clause of a SELECT, where ? is the identifier of the desired 
+** ruleset. For example:
+**
+**   SELECT vocabulary.w FROM f, vocabulary
+**    WHERE f.word MATCH $word
+**      AND f.distance<=200
+**      AND f.word=vocabulary.w
+**      AND f.ruleset=1  -- Specify the ruleset to use here
+**    LIMIT 20
+**
+** If no "ruleset = ?" constraint is specified in the WHERE clause, ruleset 
+** 0 is used.
+**
+** LIMITS
+**
+** The maximum ruleset number is 2147483647.  The maximum length of either
+** of the strings in the second or third column of the fuzzer data table
+** is 50 bytes.  The maximum cost on a rule is 1000.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+
+/* If SQLITE_DEBUG is not defined, disable assert statements. */
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
+# define NDEBUG
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Forward declaration of objects used by this implementation
+*/
+typedef struct fuzzer_vtab fuzzer_vtab;
+typedef struct fuzzer_cursor fuzzer_cursor;
+typedef struct fuzzer_rule fuzzer_rule;
+typedef struct fuzzer_seen fuzzer_seen;
+typedef struct fuzzer_stem fuzzer_stem;
+
+/*
+** Various types.
+**
+** fuzzer_cost is the "cost" of an edit operation.
+**
+** fuzzer_len is the length of a matching string.  
+**
+** fuzzer_ruleid is an ruleset identifier.
+*/
+typedef int fuzzer_cost;
+typedef signed char fuzzer_len;
+typedef int fuzzer_ruleid;
+
+/*
+** Limits
+*/
+#define FUZZER_MX_LENGTH           50   /* Maximum length of a rule string */
+#define FUZZER_MX_RULEID   2147483647   /* Maximum rule ID */
+#define FUZZER_MX_COST           1000   /* Maximum single-rule cost */
+#define FUZZER_MX_OUTPUT_LENGTH   100   /* Maximum length of an output string */
+
+
+/*
+** Each transformation rule is stored as an instance of this object.
+** All rules are kept on a linked list sorted by rCost.
+*/
+struct fuzzer_rule {
+  fuzzer_rule *pNext;         /* Next rule in order of increasing rCost */
+  char *zFrom;                /* Transform from */
+  fuzzer_cost rCost;          /* Cost of this transformation */
+  fuzzer_len nFrom, nTo;      /* Length of the zFrom and zTo strings */
+  fuzzer_ruleid iRuleset;     /* The rule set to which this rule belongs */
+  char zTo[4];                /* Transform to (extra space appended) */
+};
+
+/*
+** A stem object is used to generate variants.  It is also used to record
+** previously generated outputs.
+**
+** Every stem is added to a hash table as it is output.  Generation of
+** duplicate stems is suppressed.
+**
+** Active stems (those that might generate new outputs) are kepts on a linked
+** list sorted by increasing cost.  The cost is the sum of rBaseCost and
+** pRule->rCost.
+*/
+struct fuzzer_stem {
+  char *zBasis;              /* Word being fuzzed */
+  const fuzzer_rule *pRule;  /* Current rule to apply */
+  fuzzer_stem *pNext;        /* Next stem in rCost order */
+  fuzzer_stem *pHash;        /* Next stem with same hash on zBasis */
+  fuzzer_cost rBaseCost;     /* Base cost of getting to zBasis */
+  fuzzer_cost rCostX;        /* Precomputed rBaseCost + pRule->rCost */
+  fuzzer_len nBasis;         /* Length of the zBasis string */
+  fuzzer_len n;              /* Apply pRule at this character offset */
+};
+
+/* 
+** A fuzzer virtual-table object 
+*/
+struct fuzzer_vtab {
+  sqlite3_vtab base;         /* Base class - must be first */
+  char *zClassName;          /* Name of this class.  Default: "fuzzer" */
+  fuzzer_rule *pRule;        /* All active rules in this fuzzer */
+  int nCursor;               /* Number of active cursors */
+};
+
+#define FUZZER_HASH  4001    /* Hash table size */
+#define FUZZER_NQUEUE  20    /* Number of slots on the stem queue */
+
+/* A fuzzer cursor object */
+struct fuzzer_cursor {
+  sqlite3_vtab_cursor base;  /* Base class - must be first */
+  sqlite3_int64 iRowid;      /* The rowid of the current word */
+  fuzzer_vtab *pVtab;        /* The virtual table this cursor belongs to */
+  fuzzer_cost rLimit;        /* Maximum cost of any term */
+  fuzzer_stem *pStem;        /* Stem with smallest rCostX */
+  fuzzer_stem *pDone;        /* Stems already processed to completion */
+  fuzzer_stem *aQueue[FUZZER_NQUEUE];  /* Queue of stems with higher rCostX */
+  int mxQueue;               /* Largest used index in aQueue[] */
+  char *zBuf;                /* Temporary use buffer */
+  int nBuf;                  /* Bytes allocated for zBuf */
+  int nStem;                 /* Number of stems allocated */
+  int iRuleset;              /* Only process rules from this ruleset */
+  fuzzer_rule nullRule;      /* Null rule used first */
+  fuzzer_stem *apHash[FUZZER_HASH]; /* Hash of previously generated terms */
+};
+
+/*
+** The two input rule lists are both sorted in order of increasing
+** cost.  Merge them together into a single list, sorted by cost, and
+** return a pointer to the head of that list.
+*/
+static fuzzer_rule *fuzzerMergeRules(fuzzer_rule *pA, fuzzer_rule *pB){
+  fuzzer_rule head;
+  fuzzer_rule *pTail;
+
+  pTail =  &head;
+  while( pA && pB ){
+    if( pA->rCost<=pB->rCost ){
+      pTail->pNext = pA;
+      pTail = pA;
+      pA = pA->pNext;
+    }else{
+      pTail->pNext = pB;
+      pTail = pB;
+      pB = pB->pNext;
+    }
+  }
+  if( pA==0 ){
+    pTail->pNext = pB;
+  }else{
+    pTail->pNext = pA;
+  }
+  return head.pNext;
+}
+
+/*
+** Statement pStmt currently points to a row in the fuzzer data table. This
+** function allocates and populates a fuzzer_rule structure according to
+** the content of the row.
+**
+** If successful, *ppRule is set to point to the new object and SQLITE_OK
+** is returned. Otherwise, *ppRule is zeroed, *pzErr may be set to point
+** to an error message and an SQLite error code returned.
+*/
+static int fuzzerLoadOneRule(
+  fuzzer_vtab *p,                 /* Fuzzer virtual table handle */
+  sqlite3_stmt *pStmt,            /* Base rule on statements current row */
+  fuzzer_rule **ppRule,           /* OUT: New rule object */
+  char **pzErr                    /* OUT: Error message */
+){
+  sqlite3_int64 iRuleset = sqlite3_column_int64(pStmt, 0);
+  const char *zFrom = (const char *)sqlite3_column_text(pStmt, 1);
+  const char *zTo = (const char *)sqlite3_column_text(pStmt, 2);
+  int nCost = sqlite3_column_int(pStmt, 3);
+
+  int rc = SQLITE_OK;             /* Return code */
+  int nFrom;                      /* Size of string zFrom, in bytes */
+  int nTo;                        /* Size of string zTo, in bytes */
+  fuzzer_rule *pRule = 0;         /* New rule object to return */
+
+  if( zFrom==0 ) zFrom = "";
+  if( zTo==0 ) zTo = "";
+  nFrom = (int)strlen(zFrom);
+  nTo = (int)strlen(zTo);
+
+  /* Silently ignore null transformations */
+  if( strcmp(zFrom, zTo)==0 ){
+    *ppRule = 0;
+    return SQLITE_OK;
+  }
+
+  if( nCost<=0 || nCost>FUZZER_MX_COST ){
+    *pzErr = sqlite3_mprintf("%s: cost must be between 1 and %d", 
+        p->zClassName, FUZZER_MX_COST
+    );
+    rc = SQLITE_ERROR;
+  }else
+  if( nFrom>FUZZER_MX_LENGTH || nTo>FUZZER_MX_LENGTH ){
+    *pzErr = sqlite3_mprintf("%s: maximum string length is %d", 
+        p->zClassName, FUZZER_MX_LENGTH
+    );
+    rc = SQLITE_ERROR;    
+  }else
+  if( iRuleset<0 || iRuleset>FUZZER_MX_RULEID ){
+    *pzErr = sqlite3_mprintf("%s: ruleset must be between 0 and %d", 
+        p->zClassName, FUZZER_MX_RULEID
+    );
+    rc = SQLITE_ERROR;    
+  }else{
+
+    pRule = sqlite3_malloc( sizeof(*pRule) + nFrom + nTo );
+    if( pRule==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pRule, 0, sizeof(*pRule));
+      pRule->zFrom = &pRule->zTo[nTo+1];
+      pRule->nFrom = nFrom;
+      memcpy(pRule->zFrom, zFrom, nFrom+1);
+      memcpy(pRule->zTo, zTo, nTo+1);
+      pRule->nTo = nTo;
+      pRule->rCost = nCost;
+      pRule->iRuleset = (int)iRuleset;
+    }
+  }
+
+  *ppRule = pRule;
+  return rc;
+}
+
+/*
+** Load the content of the fuzzer data table into memory.
+*/
+static int fuzzerLoadRules(
+  sqlite3 *db,                    /* Database handle */
+  fuzzer_vtab *p,                 /* Virtual fuzzer table to configure */
+  const char *zDb,                /* Database containing rules data */
+  const char *zData,              /* Table containing rules data */
+  char **pzErr                    /* OUT: Error message */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  char *zSql;                     /* SELECT used to read from rules table */
+  fuzzer_rule *pHead = 0;
+
+  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", zDb, zData);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    int rc2;                      /* finalize() return code */
+    sqlite3_stmt *pStmt = 0;
+    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3_mprintf("%s: %s", p->zClassName, sqlite3_errmsg(db));
+    }else if( sqlite3_column_count(pStmt)!=4 ){
+      *pzErr = sqlite3_mprintf("%s: %s has %d columns, expected 4",
+          p->zClassName, zData, sqlite3_column_count(pStmt)
+      );
+      rc = SQLITE_ERROR;
+    }else{
+      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+        fuzzer_rule *pRule = 0;
+        rc = fuzzerLoadOneRule(p, pStmt, &pRule, pzErr);
+        if( pRule ){
+          pRule->pNext = pHead;
+          pHead = pRule;
+        }
+      }
+    }
+    rc2 = sqlite3_finalize(pStmt);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+  sqlite3_free(zSql);
+
+  /* All rules are now in a singly linked list starting at pHead. This
+  ** block sorts them by cost and then sets fuzzer_vtab.pRule to point to 
+  ** point to the head of the sorted list.
+  */
+  if( rc==SQLITE_OK ){
+    unsigned int i;
+    fuzzer_rule *pX;
+    fuzzer_rule *a[15];
+    for(i=0; i<sizeof(a)/sizeof(a[0]); i++) a[i] = 0;
+    while( (pX = pHead)!=0 ){
+      pHead = pX->pNext;
+      pX->pNext = 0;
+      for(i=0; a[i] && i<sizeof(a)/sizeof(a[0])-1; i++){
+        pX = fuzzerMergeRules(a[i], pX);
+        a[i] = 0;
+      }
+      a[i] = fuzzerMergeRules(a[i], pX);
+    }
+    for(pX=a[0], i=1; i<sizeof(a)/sizeof(a[0]); i++){
+      pX = fuzzerMergeRules(a[i], pX);
+    }
+    p->pRule = fuzzerMergeRules(p->pRule, pX);
+  }else{
+    /* An error has occurred. Setting p->pRule to point to the head of the
+    ** allocated list ensures that the list will be cleaned up in this case.
+    */
+    assert( p->pRule==0 );
+    p->pRule = pHead;
+  }
+
+  return rc;
+}
+
+/*
+** This function converts an SQL quoted string into an unquoted string
+** and returns a pointer to a buffer allocated using sqlite3_malloc() 
+** containing the result. The caller should eventually free this buffer
+** using sqlite3_free.
+**
+** Examples:
+**
+**     "abc"   becomes   abc
+**     'xyz'   becomes   xyz
+**     [pqr]   becomes   pqr
+**     `mno`   becomes   mno
+*/
+static char *fuzzerDequote(const char *zIn){
+  int nIn;                        /* Size of input string, in bytes */
+  char *zOut;                     /* Output (dequoted) string */
+
+  nIn = (int)strlen(zIn);
+  zOut = sqlite3_malloc(nIn+1);
+  if( zOut ){
+    char q = zIn[0];              /* Quote character (if any ) */
+
+    if( q!='[' && q!= '\'' && q!='"' && q!='`' ){
+      memcpy(zOut, zIn, nIn+1);
+    }else{
+      int iOut = 0;               /* Index of next byte to write to output */
+      int iIn;                    /* Index of next byte to read from input */
+
+      if( q=='[' ) q = ']';
+      for(iIn=1; iIn<nIn; iIn++){
+        if( zIn[iIn]==q ) iIn++;
+        zOut[iOut++] = zIn[iIn];
+      }
+    }
+    assert( (int)strlen(zOut)<=nIn );
+  }
+  return zOut;
+}
+
+/*
+** xDisconnect/xDestroy method for the fuzzer module.
+*/
+static int fuzzerDisconnect(sqlite3_vtab *pVtab){
+  fuzzer_vtab *p = (fuzzer_vtab*)pVtab;
+  assert( p->nCursor==0 );
+  while( p->pRule ){
+    fuzzer_rule *pRule = p->pRule;
+    p->pRule = pRule->pNext;
+    sqlite3_free(pRule);
+  }
+  sqlite3_free(p);
+  return SQLITE_OK;
+}
+
+/*
+** xConnect/xCreate method for the fuzzer module. Arguments are:
+**
+**   argv[0]   -> module name  ("fuzzer")
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**   argv[3]   -> fuzzer rule table name
+*/
+static int fuzzerConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc = SQLITE_OK;             /* Return code */
+  fuzzer_vtab *pNew = 0;          /* New virtual table */
+  const char *zModule = argv[0];
+  const char *zDb = argv[1];
+
+  if( argc!=4 ){
+    *pzErr = sqlite3_mprintf(
+        "%s: wrong number of CREATE VIRTUAL TABLE arguments", zModule
+    );
+    rc = SQLITE_ERROR;
+  }else{
+    int nModule;                  /* Length of zModule, in bytes */
+
+    nModule = (int)strlen(zModule);
+    pNew = sqlite3_malloc( sizeof(*pNew) + nModule + 1);
+    if( pNew==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      char *zTab;                 /* Dequoted name of fuzzer data table */
+
+      memset(pNew, 0, sizeof(*pNew));
+      pNew->zClassName = (char*)&pNew[1];
+      memcpy(pNew->zClassName, zModule, nModule+1);
+
+      zTab = fuzzerDequote(argv[3]);
+      if( zTab==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        rc = fuzzerLoadRules(db, pNew, zDb, zTab, pzErr);
+        sqlite3_free(zTab);
+      }
+
+      if( rc==SQLITE_OK ){
+        rc = sqlite3_declare_vtab(db, "CREATE TABLE x(word,distance,ruleset)");
+      }
+      if( rc!=SQLITE_OK ){
+        fuzzerDisconnect((sqlite3_vtab *)pNew);
+        pNew = 0;
+      }
+    }
+  }
+
+  *ppVtab = (sqlite3_vtab *)pNew;
+  return rc;
+}
+
+/*
+** Open a new fuzzer cursor.
+*/
+static int fuzzerOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  fuzzer_vtab *p = (fuzzer_vtab*)pVTab;
+  fuzzer_cursor *pCur;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  pCur->pVtab = p;
+  *ppCursor = &pCur->base;
+  p->nCursor++;
+  return SQLITE_OK;
+}
+
+/*
+** Free all stems in a list.
+*/
+static void fuzzerClearStemList(fuzzer_stem *pStem){
+  while( pStem ){
+    fuzzer_stem *pNext = pStem->pNext;
+    sqlite3_free(pStem);
+    pStem = pNext;
+  }
+}
+
+/*
+** Free up all the memory allocated by a cursor.  Set it rLimit to 0
+** to indicate that it is at EOF.
+*/
+static void fuzzerClearCursor(fuzzer_cursor *pCur, int clearHash){
+  int i;
+  fuzzerClearStemList(pCur->pStem);
+  fuzzerClearStemList(pCur->pDone);
+  for(i=0; i<FUZZER_NQUEUE; i++) fuzzerClearStemList(pCur->aQueue[i]);
+  pCur->rLimit = (fuzzer_cost)0;
+  if( clearHash && pCur->nStem ){
+    pCur->mxQueue = 0;
+    pCur->pStem = 0;
+    pCur->pDone = 0;
+    memset(pCur->aQueue, 0, sizeof(pCur->aQueue));
+    memset(pCur->apHash, 0, sizeof(pCur->apHash));
+  }
+  pCur->nStem = 0;
+}
+
+/*
+** Close a fuzzer cursor.
+*/
+static int fuzzerClose(sqlite3_vtab_cursor *cur){
+  fuzzer_cursor *pCur = (fuzzer_cursor *)cur;
+  fuzzerClearCursor(pCur, 0);
+  sqlite3_free(pCur->zBuf);
+  pCur->pVtab->nCursor--;
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Compute the current output term for a fuzzer_stem.
+*/
+static int fuzzerRender(
+  fuzzer_stem *pStem,   /* The stem to be rendered */
+  char **pzBuf,         /* Write results into this buffer.  realloc if needed */
+  int *pnBuf            /* Size of the buffer */
+){
+  const fuzzer_rule *pRule = pStem->pRule;
+  int n;                          /* Size of output term without nul-term */
+  char *z;                        /* Buffer to assemble output term in */
+
+  n = pStem->nBasis + pRule->nTo - pRule->nFrom;
+  if( (*pnBuf)<n+1 ){
+    (*pzBuf) = sqlite3_realloc((*pzBuf), n+100);
+    if( (*pzBuf)==0 ) return SQLITE_NOMEM;
+    (*pnBuf) = n+100;
+  }
+  n = pStem->n;
+  z = *pzBuf;
+  if( n<0 ){
+    memcpy(z, pStem->zBasis, pStem->nBasis+1);
+  }else{
+    memcpy(z, pStem->zBasis, n);
+    memcpy(&z[n], pRule->zTo, pRule->nTo);
+    memcpy(&z[n+pRule->nTo], &pStem->zBasis[n+pRule->nFrom], 
+           pStem->nBasis-n-pRule->nFrom+1);
+  }
+
+  assert( z[pStem->nBasis + pRule->nTo - pRule->nFrom]==0 );
+  return SQLITE_OK;
+}
+
+/*
+** Compute a hash on zBasis.
+*/
+static unsigned int fuzzerHash(const char *z){
+  unsigned int h = 0;
+  while( *z ){ h = (h<<3) ^ (h>>29) ^ *(z++); }
+  return h % FUZZER_HASH;
+}
+
+/*
+** Current cost of a stem
+*/
+static fuzzer_cost fuzzerCost(fuzzer_stem *pStem){
+  return pStem->rCostX = pStem->rBaseCost + pStem->pRule->rCost;
+}
+
+#if 0
+/*
+** Print a description of a fuzzer_stem on stderr.
+*/
+static void fuzzerStemPrint(
+  const char *zPrefix,
+  fuzzer_stem *pStem,
+  const char *zSuffix
+){
+  if( pStem->n<0 ){
+    fprintf(stderr, "%s[%s](%d)-->self%s",
+       zPrefix,
+       pStem->zBasis, pStem->rBaseCost,
+       zSuffix
+    );
+  }else{
+    char *zBuf = 0;
+    int nBuf = 0;
+    if( fuzzerRender(pStem, &zBuf, &nBuf)!=SQLITE_OK ) return;
+    fprintf(stderr, "%s[%s](%d)-->{%s}(%d)%s",
+      zPrefix,
+      pStem->zBasis, pStem->rBaseCost, zBuf, pStem->,
+      zSuffix
+    );
+    sqlite3_free(zBuf);
+  }
+}
+#endif
+
+/*
+** Return 1 if the string to which the cursor is point has already
+** been emitted.  Return 0 if not.  Return -1 on a memory allocation
+** failures.
+*/
+static int fuzzerSeen(fuzzer_cursor *pCur, fuzzer_stem *pStem){
+  unsigned int h;
+  fuzzer_stem *pLookup;
+
+  if( fuzzerRender(pStem, &pCur->zBuf, &pCur->nBuf)==SQLITE_NOMEM ){
+    return -1;
+  }
+  h = fuzzerHash(pCur->zBuf);
+  pLookup = pCur->apHash[h];
+  while( pLookup && strcmp(pLookup->zBasis, pCur->zBuf)!=0 ){
+    pLookup = pLookup->pHash;
+  }
+  return pLookup!=0;
+}
+
+/*
+** If argument pRule is NULL, this function returns false.
+**
+** Otherwise, it returns true if rule pRule should be skipped. A rule 
+** should be skipped if it does not belong to rule-set iRuleset, or if
+** applying it to stem pStem would create a string longer than 
+** FUZZER_MX_OUTPUT_LENGTH bytes.
+*/
+static int fuzzerSkipRule(
+  const fuzzer_rule *pRule,       /* Determine whether or not to skip this */
+  fuzzer_stem *pStem,             /* Stem rule may be applied to */
+  int iRuleset                    /* Rule-set used by the current query */
+){
+  return pRule && (
+      (pRule->iRuleset!=iRuleset)
+   || (pStem->nBasis + pRule->nTo - pRule->nFrom)>FUZZER_MX_OUTPUT_LENGTH
+  );
+}
+
+/*
+** Advance a fuzzer_stem to its next value.   Return 0 if there are
+** no more values that can be generated by this fuzzer_stem.  Return
+** -1 on a memory allocation failure.
+*/
+static int fuzzerAdvance(fuzzer_cursor *pCur, fuzzer_stem *pStem){
+  const fuzzer_rule *pRule;
+  while( (pRule = pStem->pRule)!=0 ){
+    assert( pRule==&pCur->nullRule || pRule->iRuleset==pCur->iRuleset );
+    while( pStem->n < pStem->nBasis - pRule->nFrom ){
+      pStem->n++;
+      if( pRule->nFrom==0
+       || memcmp(&pStem->zBasis[pStem->n], pRule->zFrom, pRule->nFrom)==0
+      ){
+        /* Found a rewrite case.  Make sure it is not a duplicate */
+        int rc = fuzzerSeen(pCur, pStem);
+        if( rc<0 ) return -1;
+        if( rc==0 ){
+          fuzzerCost(pStem);
+          return 1;
+        }
+      }
+    }
+    pStem->n = -1;
+    do{
+      pRule = pRule->pNext;
+    }while( fuzzerSkipRule(pRule, pStem, pCur->iRuleset) );
+    pStem->pRule = pRule;
+    if( pRule && fuzzerCost(pStem)>pCur->rLimit ) pStem->pRule = 0;
+  }
+  return 0;
+}
+
+/*
+** The two input stem lists are both sorted in order of increasing
+** rCostX.  Merge them together into a single list, sorted by rCostX, and
+** return a pointer to the head of that new list.
+*/
+static fuzzer_stem *fuzzerMergeStems(fuzzer_stem *pA, fuzzer_stem *pB){
+  fuzzer_stem head;
+  fuzzer_stem *pTail;
+
+  pTail =  &head;
+  while( pA && pB ){
+    if( pA->rCostX<=pB->rCostX ){
+      pTail->pNext = pA;
+      pTail = pA;
+      pA = pA->pNext;
+    }else{
+      pTail->pNext = pB;
+      pTail = pB;
+      pB = pB->pNext;
+    }
+  }
+  if( pA==0 ){
+    pTail->pNext = pB;
+  }else{
+    pTail->pNext = pA;
+  }
+  return head.pNext;
+}
+
+/*
+** Load pCur->pStem with the lowest-cost stem.  Return a pointer
+** to the lowest-cost stem.
+*/
+static fuzzer_stem *fuzzerLowestCostStem(fuzzer_cursor *pCur){
+  fuzzer_stem *pBest, *pX;
+  int iBest;
+  int i;
+
+  if( pCur->pStem==0 ){
+    iBest = -1;
+    pBest = 0;
+    for(i=0; i<=pCur->mxQueue; i++){
+      pX = pCur->aQueue[i];
+      if( pX==0 ) continue;
+      if( pBest==0 || pBest->rCostX>pX->rCostX ){
+        pBest = pX;
+        iBest = i;
+      }
+    } 
+    if( pBest ){
+      pCur->aQueue[iBest] = pBest->pNext;
+      pBest->pNext = 0;
+      pCur->pStem = pBest;
+    }
+  }
+  return pCur->pStem;
+}
+
+/*
+** Insert pNew into queue of pending stems.  Then find the stem
+** with the lowest rCostX and move it into pCur->pStem.
+** list.  The insert is done such the pNew is in the correct order
+** according to fuzzer_stem.zBaseCost+fuzzer_stem.pRule->rCost.
+*/
+static fuzzer_stem *fuzzerInsert(fuzzer_cursor *pCur, fuzzer_stem *pNew){
+  fuzzer_stem *pX;
+  int i;
+
+  /* If pCur->pStem exists and is greater than pNew, then make pNew
+  ** the new pCur->pStem and insert the old pCur->pStem instead.
+  */
+  if( (pX = pCur->pStem)!=0 && pX->rCostX>pNew->rCostX ){
+    pNew->pNext = 0;
+    pCur->pStem = pNew;
+    pNew = pX;
+  }
+
+  /* Insert the new value */
+  pNew->pNext = 0;
+  pX = pNew;
+  for(i=0; i<=pCur->mxQueue; i++){
+    if( pCur->aQueue[i] ){
+      pX = fuzzerMergeStems(pX, pCur->aQueue[i]);
+      pCur->aQueue[i] = 0;
+    }else{
+      pCur->aQueue[i] = pX;
+      break;
+    }
+  }
+  if( i>pCur->mxQueue ){
+    if( i<FUZZER_NQUEUE ){
+      pCur->mxQueue = i;
+      pCur->aQueue[i] = pX;
+    }else{
+      assert( pCur->mxQueue==FUZZER_NQUEUE-1 );
+      pX = fuzzerMergeStems(pX, pCur->aQueue[FUZZER_NQUEUE-1]);
+      pCur->aQueue[FUZZER_NQUEUE-1] = pX;
+    }
+  }
+
+  return fuzzerLowestCostStem(pCur);
+}
+
+/*
+** Allocate a new fuzzer_stem.  Add it to the hash table but do not
+** link it into either the pCur->pStem or pCur->pDone lists.
+*/
+static fuzzer_stem *fuzzerNewStem(
+  fuzzer_cursor *pCur,
+  const char *zWord,
+  fuzzer_cost rBaseCost
+){
+  fuzzer_stem *pNew;
+  fuzzer_rule *pRule;
+  unsigned int h;
+
+  pNew = sqlite3_malloc( sizeof(*pNew) + (int)strlen(zWord) + 1 );
+  if( pNew==0 ) return 0;
+  memset(pNew, 0, sizeof(*pNew));
+  pNew->zBasis = (char*)&pNew[1];
+  pNew->nBasis = (int)strlen(zWord);
+  memcpy(pNew->zBasis, zWord, pNew->nBasis+1);
+  pRule = pCur->pVtab->pRule;
+  while( fuzzerSkipRule(pRule, pNew, pCur->iRuleset) ){
+    pRule = pRule->pNext;
+  }
+  pNew->pRule = pRule;
+  pNew->n = -1;
+  pNew->rBaseCost = pNew->rCostX = rBaseCost;
+  h = fuzzerHash(pNew->zBasis);
+  pNew->pHash = pCur->apHash[h];
+  pCur->apHash[h] = pNew;
+  pCur->nStem++;
+  return pNew;
+}
+
+
+/*
+** Advance a cursor to its next row of output
+*/
+static int fuzzerNext(sqlite3_vtab_cursor *cur){
+  fuzzer_cursor *pCur = (fuzzer_cursor*)cur;
+  int rc;
+  fuzzer_stem *pStem, *pNew;
+
+  pCur->iRowid++;
+
+  /* Use the element the cursor is currently point to to create
+  ** a new stem and insert the new stem into the priority queue.
+  */
+  pStem = pCur->pStem;
+  if( pStem->rCostX>0 ){
+    rc = fuzzerRender(pStem, &pCur->zBuf, &pCur->nBuf);
+    if( rc==SQLITE_NOMEM ) return SQLITE_NOMEM;
+    pNew = fuzzerNewStem(pCur, pCur->zBuf, pStem->rCostX);
+    if( pNew ){
+      if( fuzzerAdvance(pCur, pNew)==0 ){
+        pNew->pNext = pCur->pDone;
+        pCur->pDone = pNew;
+      }else{
+        if( fuzzerInsert(pCur, pNew)==pNew ){
+          return SQLITE_OK;
+        }
+      }
+    }else{
+      return SQLITE_NOMEM;
+    }
+  }
+
+  /* Adjust the priority queue so that the first element of the
+  ** stem list is the next lowest cost word.
+  */
+  while( (pStem = pCur->pStem)!=0 ){
+    int res = fuzzerAdvance(pCur, pStem);
+    if( res<0 ){
+      return SQLITE_NOMEM;
+    }else if( res>0 ){
+      pCur->pStem = 0;
+      pStem = fuzzerInsert(pCur, pStem);
+      if( (rc = fuzzerSeen(pCur, pStem))!=0 ){
+        if( rc<0 ) return SQLITE_NOMEM;
+        continue;
+      }
+      return SQLITE_OK;  /* New word found */
+    }
+    pCur->pStem = 0;
+    pStem->pNext = pCur->pDone;
+    pCur->pDone = pStem;
+    if( fuzzerLowestCostStem(pCur) ){
+      rc = fuzzerSeen(pCur, pCur->pStem);
+      if( rc<0 ) return SQLITE_NOMEM;
+      if( rc==0 ){
+        return SQLITE_OK;
+      }
+    }
+  }
+
+  /* Reach this point only if queue has been exhausted and there is
+  ** nothing left to be output. */
+  pCur->rLimit = (fuzzer_cost)0;
+  return SQLITE_OK;
+}
+
+/*
+** Called to "rewind" a cursor back to the beginning so that
+** it starts its output over again.  Always called at least once
+** prior to any fuzzerColumn, fuzzerRowid, or fuzzerEof call.
+*/
+static int fuzzerFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  fuzzer_cursor *pCur = (fuzzer_cursor *)pVtabCursor;
+  const char *zWord = "";
+  fuzzer_stem *pStem;
+  int idx;
+
+  fuzzerClearCursor(pCur, 1);
+  pCur->rLimit = 2147483647;
+  idx = 0;
+  if( idxNum & 1 ){
+    zWord = (const char*)sqlite3_value_text(argv[0]);
+    idx++;
+  }
+  if( idxNum & 2 ){
+    pCur->rLimit = (fuzzer_cost)sqlite3_value_int(argv[idx]);
+    idx++;
+  }
+  if( idxNum & 4 ){
+    pCur->iRuleset = (fuzzer_cost)sqlite3_value_int(argv[idx]);
+    idx++;
+  }
+  pCur->nullRule.pNext = pCur->pVtab->pRule;
+  pCur->nullRule.rCost = 0;
+  pCur->nullRule.nFrom = 0;
+  pCur->nullRule.nTo = 0;
+  pCur->nullRule.zFrom = "";
+  pCur->iRowid = 1;
+  assert( pCur->pStem==0 );
+
+  /* If the query term is longer than FUZZER_MX_OUTPUT_LENGTH bytes, this
+  ** query will return zero rows.  */
+  if( (int)strlen(zWord)<FUZZER_MX_OUTPUT_LENGTH ){
+    pCur->pStem = pStem = fuzzerNewStem(pCur, zWord, (fuzzer_cost)0);
+    if( pStem==0 ) return SQLITE_NOMEM;
+    pStem->pRule = &pCur->nullRule;
+    pStem->n = pStem->nBasis;
+  }else{
+    pCur->rLimit = 0;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Only the word and distance columns have values.  All other columns
+** return NULL
+*/
+static int fuzzerColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  fuzzer_cursor *pCur = (fuzzer_cursor*)cur;
+  if( i==0 ){
+    /* the "word" column */
+    if( fuzzerRender(pCur->pStem, &pCur->zBuf, &pCur->nBuf)==SQLITE_NOMEM ){
+      return SQLITE_NOMEM;
+    }
+    sqlite3_result_text(ctx, pCur->zBuf, -1, SQLITE_TRANSIENT);
+  }else if( i==1 ){
+    /* the "distance" column */
+    sqlite3_result_int(ctx, pCur->pStem->rCostX);
+  }else{
+    /* All other columns are NULL */
+    sqlite3_result_null(ctx);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The rowid.
+*/
+static int fuzzerRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  fuzzer_cursor *pCur = (fuzzer_cursor*)cur;
+  *pRowid = pCur->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** When the fuzzer_cursor.rLimit value is 0 or less, that is a signal
+** that the cursor has nothing more to output.
+*/
+static int fuzzerEof(sqlite3_vtab_cursor *cur){
+  fuzzer_cursor *pCur = (fuzzer_cursor*)cur;
+  return pCur->rLimit<=(fuzzer_cost)0;
+}
+
+/*
+** Search for terms of these forms:
+**
+**   (A)    word MATCH $str
+**   (B1)   distance < $value
+**   (B2)   distance <= $value
+**   (C)    ruleid == $ruleid
+**
+** The distance< and distance<= are both treated as distance<=.
+** The query plan number is a bit vector:
+**
+**   bit 1:   Term of the form (A) found
+**   bit 2:   Term like (B1) or (B2) found
+**   bit 3:   Term like (C) found
+**
+** If bit-1 is set, $str is always in filter.argv[0].  If bit-2 is set
+** then $value is in filter.argv[0] if bit-1 is clear and is in 
+** filter.argv[1] if bit-1 is set.  If bit-3 is set, then $ruleid is
+** in filter.argv[0] if bit-1 and bit-2 are both zero, is in
+** filter.argv[1] if exactly one of bit-1 and bit-2 are set, and is in
+** filter.argv[2] if both bit-1 and bit-2 are set.
+*/
+static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int iPlan = 0;
+  int iDistTerm = -1;
+  int iRulesetTerm = -1;
+  int i;
+  const struct sqlite3_index_constraint *pConstraint;
+  pConstraint = pIdxInfo->aConstraint;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( (iPlan & 1)==0 
+     && pConstraint->iColumn==0
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH
+    ){
+      iPlan |= 1;
+      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+    if( (iPlan & 2)==0
+     && pConstraint->iColumn==1
+     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
+           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
+    ){
+      iPlan |= 2;
+      iDistTerm = i;
+    }
+    if( (iPlan & 4)==0
+     && pConstraint->iColumn==2
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 4;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+      iRulesetTerm = i;
+    }
+  }
+  if( iPlan & 2 ){
+    pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = 1+((iPlan&1)!=0);
+  }
+  if( iPlan & 4 ){
+    int idx = 1;
+    if( iPlan & 1 ) idx++;
+    if( iPlan & 2 ) idx++;
+    pIdxInfo->aConstraintUsage[iRulesetTerm].argvIndex = idx;
+  }
+  pIdxInfo->idxNum = iPlan;
+  if( pIdxInfo->nOrderBy==1
+   && pIdxInfo->aOrderBy[0].iColumn==1
+   && pIdxInfo->aOrderBy[0].desc==0
+  ){
+    pIdxInfo->orderByConsumed = 1;
+  }
+  pIdxInfo->estimatedCost = (double)10000;
+   
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that implements the "fuzzer".
+*/
+static sqlite3_module fuzzerModule = {
+  0,                           /* iVersion */
+  fuzzerConnect,
+  fuzzerConnect,
+  fuzzerBestIndex,
+  fuzzerDisconnect, 
+  fuzzerDisconnect,
+  fuzzerOpen,                  /* xOpen - open a cursor */
+  fuzzerClose,                 /* xClose - close a cursor */
+  fuzzerFilter,                /* xFilter - configure scan constraints */
+  fuzzerNext,                  /* xNext - advance a cursor */
+  fuzzerEof,                   /* xEof - check for end of scan */
+  fuzzerColumn,                /* xColumn - read data */
+  fuzzerRowid,                 /* xRowid - read data */
+  0,                           /* xUpdate */
+  0,                           /* xBegin */
+  0,                           /* xSync */
+  0,                           /* xCommit */
+  0,                           /* xRollback */
+  0,                           /* xFindMethod */
+  0,                           /* xRename */
+};
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fuzzer_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  rc = sqlite3_create_module(db, "fuzzer", &fuzzerModule, 0);
+#endif
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/ieee754.c b/lib/libsqlite3/ext/misc/ieee754.c
new file mode 100644
index 00000000000..436b11e0c53
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/ieee754.c
@@ -0,0 +1,131 @@
+/*
+** 2013-04-17
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements functions for the exact display
+** and input of IEEE754 Binary64 floating-point numbers.
+**
+**   ieee754(X)
+**   ieee754(Y,Z)
+**
+** In the first form, the value X should be a floating-point number.
+** The function will return a string of the form 'ieee754(Y,Z)' where
+** Y and Z are integers such that X==Y*pow(w.0,Z).
+**
+** In the second form, Y and Z are integers which are the mantissa and
+** base-2 exponent of a new floating point number.  The function returns
+** a floating-point value equal to Y*pow(2.0,Z).
+**
+** Examples:
+**
+**     ieee754(2.0)       ->     'ieee754(2,0)'
+**     ieee754(45.25)     ->     'ieee754(181,-2)'
+**     ieee754(2, 0)      ->     2.0
+**     ieee754(181, -2)   ->     45.25
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+/*
+** Implementation of the ieee754() function
+*/
+static void ieee754func(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  if( argc==1 ){
+    sqlite3_int64 m, a;
+    double r;
+    int e;
+    int isNeg;
+    char zResult[100];
+    assert( sizeof(m)==sizeof(r) );
+    if( sqlite3_value_type(argv[0])!=SQLITE_FLOAT ) return;
+    r = sqlite3_value_double(argv[0]);
+    if( r<0.0 ){
+      isNeg = 1;
+      r = -r;
+    }else{
+      isNeg = 0;
+    }
+    memcpy(&a,&r,sizeof(a));
+    if( a==0 ){
+      e = 0;
+      m = 0;
+    }else{
+      e = a>>52;
+      m = a & ((((sqlite3_int64)1)<<52)-1);
+      m |= ((sqlite3_int64)1)<<52;
+      while( e<1075 && m>0 && (m&1)==0 ){
+        m >>= 1;
+        e++;
+      }
+      if( isNeg ) m = -m;
+    }
+    sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
+                     m, e-1075);
+    sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
+  }else if( argc==2 ){
+    sqlite3_int64 m, e, a;
+    double r;
+    int isNeg = 0;
+    m = sqlite3_value_int64(argv[0]);
+    e = sqlite3_value_int64(argv[1]);
+    if( m<0 ){
+      isNeg = 1;
+      m = -m;
+      if( m<0 ) return;
+    }else if( m==0 && e>1000 && e<1000 ){
+      sqlite3_result_double(context, 0.0);
+      return;
+    }
+    while( (m>>32)&0xffe00000 ){
+      m >>= 1;
+      e++;
+    }
+    while( ((m>>32)&0xfff00000)==0 ){
+      m <<= 1;
+      e--;
+    }
+    e += 1075;
+    if( e<0 ) e = m = 0;
+    if( e>0x7ff ) m = 0;
+    a = m & ((((sqlite3_int64)1)<<52)-1);
+    a |= e<<52;
+    if( isNeg ) a |= ((sqlite3_int64)1)<<63;
+    memcpy(&r, &a, sizeof(r));
+    sqlite3_result_double(context, r);
+  }
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_ieee_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "ieee754", 1, SQLITE_UTF8, 0,
+                               ieee754func, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "ieee754", 2, SQLITE_UTF8, 0,
+                                 ieee754func, 0, 0);
+  }
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/nextchar.c b/lib/libsqlite3/ext/misc/nextchar.c
new file mode 100644
index 00000000000..e063043e04a
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/nextchar.c
@@ -0,0 +1,265 @@
+/*
+** 2013-02-28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code to implement the next_char(A,T,F,W) SQL function.
+**
+** The next_char(A,T,F,H) function finds all valid "next" characters for
+** string A given the vocabulary in T.F.  The T.F field should be indexed.
+** If the W value exists and is a non-empty string, then it is an SQL
+** expression that limits the entries in T.F that will be considered.
+**
+** For example, suppose an application has a dictionary like this:
+**
+**   CREATE TABLE dictionary(word TEXT UNIQUE);
+**
+** Further suppose that for user keypad entry, it is desired to disable
+** (gray out) keys that are not valid as the next character.  If the
+** the user has previously entered (say) 'cha' then to find all allowed
+** next characters (and thereby determine when keys should not be grayed
+** out) run the following query:
+**
+**   SELECT next_char('cha','dictionary','word');
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <string.h>
+
+/*
+** A structure to hold context of the next_char() computation across
+** nested function calls.
+*/
+typedef struct nextCharContext nextCharContext;
+struct nextCharContext {
+  sqlite3 *db;                      /* Database connection */
+  sqlite3_stmt *pStmt;              /* Prepared statement used to query */
+  const unsigned char *zPrefix;     /* Prefix to scan */
+  int nPrefix;                      /* Size of zPrefix in bytes */
+  int nAlloc;                       /* Space allocated to aResult */
+  int nUsed;                        /* Space used in aResult */
+  unsigned int *aResult;            /* Array of next characters */
+  int mallocFailed;                 /* True if malloc fails */
+  int otherError;                   /* True for any other failure */
+};
+
+/*
+** Append a result character if the character is not already in the
+** result.
+*/
+static void nextCharAppend(nextCharContext *p, unsigned c){
+  int i;
+  for(i=0; i<p->nUsed; i++){
+    if( p->aResult[i]==c ) return;
+  }
+  if( p->nUsed+1 > p->nAlloc ){
+    unsigned int *aNew;
+    int n = p->nAlloc*2 + 30;
+    aNew = sqlite3_realloc(p->aResult, n*sizeof(unsigned int));
+    if( aNew==0 ){
+      p->mallocFailed = 1;
+      return;
+    }else{
+      p->aResult = aNew;
+      p->nAlloc = n;
+    }
+  }
+  p->aResult[p->nUsed++] = c;
+}
+
+/*
+** Write a character into z[] as UTF8.  Return the number of bytes needed
+** to hold the character
+*/
+static int writeUtf8(unsigned char *z, unsigned c){
+  if( c<0x00080 ){
+    z[0] = (unsigned char)(c&0xff);
+    return 1;
+  }
+  if( c<0x00800 ){
+    z[0] = 0xC0 + (unsigned char)((c>>6)&0x1F);
+    z[1] = 0x80 + (unsigned char)(c & 0x3F);
+    return 2;
+  }
+  if( c<0x10000 ){
+    z[0] = 0xE0 + (unsigned char)((c>>12)&0x0F);
+    z[1] = 0x80 + (unsigned char)((c>>6) & 0x3F);
+    z[2] = 0x80 + (unsigned char)(c & 0x3F);
+    return 3;
+  }
+  z[0] = 0xF0 + (unsigned char)((c>>18) & 0x07);
+  z[1] = 0x80 + (unsigned char)((c>>12) & 0x3F);
+  z[2] = 0x80 + (unsigned char)((c>>6) & 0x3F);
+  z[3] = 0x80 + (unsigned char)(c & 0x3F);
+  return 4;
+}
+
+/*
+** Read a UTF8 character out of z[] and write it into *pOut.  Return
+** the number of bytes in z[] that were used to construct the character.
+*/
+static int readUtf8(const unsigned char *z, unsigned *pOut){
+  static const unsigned char validBits[] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+  };
+  unsigned c = z[0];
+  if( c<0xc0 ){
+    *pOut = c;
+    return 1;
+  }else{
+    int n = 1;
+    c = validBits[c-0xc0];
+    while( (z[n] & 0xc0)==0x80 ){
+      c = (c<<6) + (0x3f & z[n++]);
+    }
+    if( c<0x80 || (c&0xFFFFF800)==0xD800 || (c&0xFFFFFFFE)==0xFFFE ){
+      c = 0xFFFD;
+    }
+    *pOut = c;
+    return n;
+  }
+}
+
+/*
+** The nextCharContext structure has been set up.  Add all "next" characters
+** to the result set.
+*/
+static void findNextChars(nextCharContext *p){
+  unsigned cPrev = 0;
+  unsigned char zPrev[8];
+  int n, rc;
+  
+  for(;;){
+    sqlite3_bind_text(p->pStmt, 1, (char*)p->zPrefix, p->nPrefix,
+                      SQLITE_STATIC);
+    n = writeUtf8(zPrev, cPrev+1);
+    sqlite3_bind_text(p->pStmt, 2, (char*)zPrev, n, SQLITE_STATIC);
+    rc = sqlite3_step(p->pStmt);
+    if( rc==SQLITE_DONE ){
+      sqlite3_reset(p->pStmt);
+      return;
+    }else if( rc!=SQLITE_ROW ){
+      p->otherError = rc;
+      return;
+    }else{
+      const unsigned char *zOut = sqlite3_column_text(p->pStmt, 0);
+      unsigned cNext;
+      n = readUtf8(zOut+p->nPrefix, &cNext);
+      sqlite3_reset(p->pStmt);
+      nextCharAppend(p, cNext);
+      cPrev = cNext;
+      if( p->mallocFailed ) return;
+    }
+  }
+}
+
+
+/*
+** next_character(A,T,F,W)
+**
+** Return a string composted of all next possible characters after
+** A for elements of T.F.  If W is supplied, then it is an SQL expression
+** that limits the elements in T.F that are considered.
+*/
+static void nextCharFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  nextCharContext c;
+  const unsigned char *zTable = sqlite3_value_text(argv[1]);
+  const unsigned char *zField = sqlite3_value_text(argv[2]);
+  const unsigned char *zWhere;
+  char *zSql;
+  int rc;
+
+  memset(&c, 0, sizeof(c));
+  c.db = sqlite3_context_db_handle(context);
+  c.zPrefix = sqlite3_value_text(argv[0]);
+  c.nPrefix = sqlite3_value_bytes(argv[0]);
+  if( zTable==0 || zField==0 || c.zPrefix==0 ) return;
+  if( argc<4
+   || (zWhere = sqlite3_value_text(argv[3]))==0
+   || zWhere[0]==0
+  ){
+    zSql = sqlite3_mprintf(
+        "SELECT \"%w\" FROM \"%w\""
+        " WHERE \"%w\">=(?1 || ?2)"
+        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
+        " ORDER BY 1 ASC LIMIT 1",
+        zField, zTable, zField, zField);
+  }else{
+    zSql = sqlite3_mprintf(
+        "SELECT \"%w\" FROM \"%w\""
+        " WHERE \"%w\">=(?1 || ?2)"
+        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
+        "   AND (%s)"
+        " ORDER BY 1 ASC LIMIT 1",
+        zField, zTable, zField, zField, zWhere);
+  }
+  if( zSql==0 ){
+    sqlite3_result_error_nomem(context);
+    return;
+  }
+
+  rc = sqlite3_prepare_v2(c.db, zSql, -1, &c.pStmt, 0);
+  sqlite3_free(zSql);
+  if( rc ){
+    sqlite3_result_error(context, sqlite3_errmsg(c.db), -1);
+    return;
+  }
+  findNextChars(&c);
+  if( c.mallocFailed ){
+    sqlite3_result_error_nomem(context);
+  }else{
+    unsigned char *pRes;
+    pRes = sqlite3_malloc( c.nUsed*4 + 1 );
+    if( pRes==0 ){
+      sqlite3_result_error_nomem(context);
+    }else{
+      int i;
+      int n = 0;
+      for(i=0; i<c.nUsed; i++){
+        n += writeUtf8(pRes+n, c.aResult[i]);
+      }
+      pRes[n] = 0;
+      sqlite3_result_text(context, (const char*)pRes, n, sqlite3_free);
+    }
+  }
+  sqlite3_finalize(c.pStmt);
+  sqlite3_free(c.aResult);
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_nextchar_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "next_char", 3, SQLITE_UTF8, 0,
+                               nextCharFunc, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "next_char", 4, SQLITE_UTF8, 0,
+                                 nextCharFunc, 0, 0);
+  }
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/regexp.c b/lib/libsqlite3/ext/misc/regexp.c
new file mode 100644
index 00000000000..16fa7d0b968
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/regexp.c
@@ -0,0 +1,756 @@
+/*
+** 2012-11-13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** The code in this file implements a compact but reasonably
+** efficient regular-expression matcher for posix extended regular
+** expressions against UTF8 text.
+**
+** This file is an SQLite extension.  It registers a single function
+** named "regexp(A,B)" where A is the regular expression and B is the
+** string to be matched.  By registering this function, SQLite will also
+** then implement the "B regexp A" operator.  Note that with the function
+** the regular expression comes first, but with the operator it comes
+** second.
+**
+**  The following regular expression syntax is supported:
+**
+**     X*      zero or more occurrences of X
+**     X+      one or more occurrences of X
+**     X?      zero or one occurrences of X
+**     X{p,q}  between p and q occurrences of X
+**     (X)     match X
+**     X|Y     X or Y
+**     ^X      X occurring at the beginning of the string
+**     X$      X occurring at the end of the string
+**     .       Match any single character
+**     \c      Character c where c is one of \{}()[]|*+?.
+**     \c      C-language escapes for c in afnrtv.  ex: \t or \n
+**     \uXXXX  Where XXXX is exactly 4 hex digits, unicode value XXXX
+**     \xXX    Where XX is exactly 2 hex digits, unicode value XX
+**     [abc]   Any single character from the set abc
+**     [^abc]  Any single character not in the set abc
+**     [a-z]   Any single character in the range a-z
+**     [^a-z]  Any single character not in the range a-z
+**     \b      Word boundary
+**     \w      Word character.  [A-Za-z0-9_]
+**     \W      Non-word character
+**     \d      Digit
+**     \D      Non-digit
+**     \s      Whitespace character
+**     \S      Non-whitespace character
+**
+** A nondeterministic finite automaton (NFA) is used for matching, so the
+** performance is bounded by O(N*M) where N is the size of the regular
+** expression and M is the size of the input string.  The matcher never
+** exhibits exponential behavior.  Note that the X{p,q} operator expands
+** to p copies of X following by q-p copies of X? and that the size of the
+** regular expression in the O(N*M) performance bound is computed after
+** this expansion.
+*/
+#include <string.h>
+#include <stdlib.h>
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+
+/*
+** The following #defines change the names of some functions implemented in
+** this file to prevent name collisions with C-library functions of the
+** same name.
+*/
+#define re_match   sqlite3re_match
+#define re_compile sqlite3re_compile
+#define re_free    sqlite3re_free
+
+/* The end-of-input character */
+#define RE_EOF            0    /* End of input */
+
+/* The NFA is implemented as sequence of opcodes taken from the following
+** set.  Each opcode has a single integer argument.
+*/
+#define RE_OP_MATCH       1    /* Match the one character in the argument */
+#define RE_OP_ANY         2    /* Match any one character.  (Implements ".") */
+#define RE_OP_ANYSTAR     3    /* Special optimized version of .* */
+#define RE_OP_FORK        4    /* Continue to both next and opcode at iArg */
+#define RE_OP_GOTO        5    /* Jump to opcode at iArg */
+#define RE_OP_ACCEPT      6    /* Halt and indicate a successful match */
+#define RE_OP_CC_INC      7    /* Beginning of a [...] character class */
+#define RE_OP_CC_EXC      8    /* Beginning of a [^...] character class */
+#define RE_OP_CC_VALUE    9    /* Single value in a character class */
+#define RE_OP_CC_RANGE   10    /* Range of values in a character class */
+#define RE_OP_WORD       11    /* Perl word character [A-Za-z0-9_] */
+#define RE_OP_NOTWORD    12    /* Not a perl word character */
+#define RE_OP_DIGIT      13    /* digit:  [0-9] */
+#define RE_OP_NOTDIGIT   14    /* Not a digit */
+#define RE_OP_SPACE      15    /* space:  [ \t\n\r\v\f] */
+#define RE_OP_NOTSPACE   16    /* Not a digit */
+#define RE_OP_BOUNDARY   17    /* Boundary between word and non-word */
+
+/* Each opcode is a "state" in the NFA */
+typedef unsigned short ReStateNumber;
+
+/* Because this is an NFA and not a DFA, multiple states can be active at
+** once.  An instance of the following object records all active states in
+** the NFA.  The implementation is optimized for the common case where the
+** number of actives states is small.
+*/
+typedef struct ReStateSet {
+  unsigned nState;            /* Number of current states */
+  ReStateNumber *aState;      /* Current states */
+} ReStateSet;
+
+/* An input string read one character at a time.
+*/
+typedef struct ReInput ReInput;
+struct ReInput {
+  const unsigned char *z;  /* All text */
+  int i;                   /* Next byte to read */
+  int mx;                  /* EOF when i>=mx */
+};
+
+/* A compiled NFA (or an NFA that is in the process of being compiled) is
+** an instance of the following object.
+*/
+typedef struct ReCompiled ReCompiled;
+struct ReCompiled {
+  ReInput sIn;                /* Regular expression text */
+  const char *zErr;           /* Error message to return */
+  char *aOp;                  /* Operators for the virtual machine */
+  int *aArg;                  /* Arguments to each operator */
+  unsigned (*xNextChar)(ReInput*);  /* Next character function */
+  unsigned char zInit[12];    /* Initial text to match */
+  int nInit;                  /* Number of characters in zInit */
+  unsigned nState;            /* Number of entries in aOp[] and aArg[] */
+  unsigned nAlloc;            /* Slots allocated for aOp[] and aArg[] */
+};
+
+/* Add a state to the given state set if it is not already there */
+static void re_add_state(ReStateSet *pSet, int newState){
+  unsigned i;
+  for(i=0; i<pSet->nState; i++) if( pSet->aState[i]==newState ) return;
+  pSet->aState[pSet->nState++] = newState;
+}
+
+/* Extract the next unicode character from *pzIn and return it.  Advance
+** *pzIn to the first byte past the end of the character returned.  To
+** be clear:  this routine converts utf8 to unicode.  This routine is 
+** optimized for the common case where the next character is a single byte.
+*/
+static unsigned re_next_char(ReInput *p){
+  unsigned c;
+  if( p->i>=p->mx ) return 0;
+  c = p->z[p->i++];
+  if( c>=0x80 ){
+    if( (c&0xe0)==0xc0 && p->i<p->mx && (p->z[p->i]&0xc0)==0x80 ){
+      c = (c&0x1f)<<6 | (p->z[p->i++]&0x3f);
+      if( c<0x80 ) c = 0xfffd;
+    }else if( (c&0xf0)==0xe0 && p->i+1<p->mx && (p->z[p->i]&0xc0)==0x80
+           && (p->z[p->i+1]&0xc0)==0x80 ){
+      c = (c&0x0f)<<12 | ((p->z[p->i]&0x3f)<<6) | (p->z[p->i+1]&0x3f);
+      p->i += 2;
+      if( c<=0x3ff || (c>=0xd800 && c<=0xdfff) ) c = 0xfffd;
+    }else if( (c&0xf8)==0xf0 && p->i+3<p->mx && (p->z[p->i]&0xc0)==0x80
+           && (p->z[p->i+1]&0xc0)==0x80 && (p->z[p->i+2]&0xc0)==0x80 ){
+      c = (c&0x07)<<18 | ((p->z[p->i]&0x3f)<<12) | ((p->z[p->i+1]&0x3f)<<6)
+                       | (p->z[p->i+2]&0x3f);
+      p->i += 3;
+      if( c<=0xffff || c>0x10ffff ) c = 0xfffd;
+    }else{
+      c = 0xfffd;
+    }
+  }
+  return c;
+}
+static unsigned re_next_char_nocase(ReInput *p){
+  unsigned c = re_next_char(p);
+  if( c>='A' && c<='Z' ) c += 'a' - 'A';
+  return c;
+}
+
+/* Return true if c is a perl "word" character:  [A-Za-z0-9_] */
+static int re_word_char(int c){
+  return (c>='0' && c<='9') || (c>='a' && c<='z')
+      || (c>='A' && c<='Z') || c=='_';
+}
+
+/* Return true if c is a "digit" character:  [0-9] */
+static int re_digit_char(int c){
+  return (c>='0' && c<='9');
+}
+
+/* Return true if c is a perl "space" character:  [ \t\r\n\v\f] */
+static int re_space_char(int c){
+  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
+}
+
+/* Run a compiled regular expression on the zero-terminated input
+** string zIn[].  Return true on a match and false if there is no match.
+*/
+static int re_match(ReCompiled *pRe, const unsigned char *zIn, int nIn){
+  ReStateSet aStateSet[2], *pThis, *pNext;
+  ReStateNumber aSpace[100];
+  ReStateNumber *pToFree;
+  unsigned int i = 0;
+  unsigned int iSwap = 0;
+  int c = RE_EOF+1;
+  int cPrev = 0;
+  int rc = 0;
+  ReInput in;
+
+  in.z = zIn;
+  in.i = 0;
+  in.mx = nIn>=0 ? nIn : (int)strlen((char const*)zIn);
+
+  /* Look for the initial prefix match, if there is one. */
+  if( pRe->nInit ){
+    unsigned char x = pRe->zInit[0];
+    while( in.i+pRe->nInit<=in.mx 
+     && (zIn[in.i]!=x ||
+         strncmp((const char*)zIn+in.i, (const char*)pRe->zInit, pRe->nInit)!=0)
+    ){
+      in.i++;
+    }
+    if( in.i+pRe->nInit>in.mx ) return 0;
+  }
+
+  if( pRe->nState<=(sizeof(aSpace)/(sizeof(aSpace[0])*2)) ){
+    pToFree = 0;
+    aStateSet[0].aState = aSpace;
+  }else{
+    pToFree = sqlite3_malloc( sizeof(ReStateNumber)*2*pRe->nState );
+    if( pToFree==0 ) return -1;
+    aStateSet[0].aState = pToFree;
+  }
+  aStateSet[1].aState = &aStateSet[0].aState[pRe->nState];
+  pNext = &aStateSet[1];
+  pNext->nState = 0;
+  re_add_state(pNext, 0);
+  while( c!=RE_EOF && pNext->nState>0 ){
+    cPrev = c;
+    c = pRe->xNextChar(&in);
+    pThis = pNext;
+    pNext = &aStateSet[iSwap];
+    iSwap = 1 - iSwap;
+    pNext->nState = 0;
+    for(i=0; i<pThis->nState; i++){
+      int x = pThis->aState[i];
+      switch( pRe->aOp[x] ){
+        case RE_OP_MATCH: {
+          if( pRe->aArg[x]==c ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_ANY: {
+          re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_WORD: {
+          if( re_word_char(c) ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_NOTWORD: {
+          if( !re_word_char(c) ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_DIGIT: {
+          if( re_digit_char(c) ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_NOTDIGIT: {
+          if( !re_digit_char(c) ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_SPACE: {
+          if( re_space_char(c) ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_NOTSPACE: {
+          if( !re_space_char(c) ) re_add_state(pNext, x+1);
+          break;
+        }
+        case RE_OP_BOUNDARY: {
+          if( re_word_char(c)!=re_word_char(cPrev) ) re_add_state(pThis, x+1);
+          break;
+        }
+        case RE_OP_ANYSTAR: {
+          re_add_state(pNext, x);
+          re_add_state(pThis, x+1);
+          break;
+        }
+        case RE_OP_FORK: {
+          re_add_state(pThis, x+pRe->aArg[x]);
+          re_add_state(pThis, x+1);
+          break;
+        }
+        case RE_OP_GOTO: {
+          re_add_state(pThis, x+pRe->aArg[x]);
+          break;
+        }
+        case RE_OP_ACCEPT: {
+          rc = 1;
+          goto re_match_end;
+        }
+        case RE_OP_CC_INC:
+        case RE_OP_CC_EXC: {
+          int j = 1;
+          int n = pRe->aArg[x];
+          int hit = 0;
+          for(j=1; j>0 && j<n; j++){
+            if( pRe->aOp[x+j]==RE_OP_CC_VALUE ){
+              if( pRe->aArg[x+j]==c ){
+                hit = 1;
+                j = -1;
+              }
+            }else{
+              if( pRe->aArg[x+j]<=c && pRe->aArg[x+j+1]>=c ){
+                hit = 1;
+                j = -1;
+              }else{
+                j++;
+              }
+            }
+          }
+          if( pRe->aOp[x]==RE_OP_CC_EXC ) hit = !hit;
+          if( hit ) re_add_state(pNext, x+n);
+          break;            
+        }
+      }
+    }
+  }
+  for(i=0; i<pNext->nState; i++){
+    if( pRe->aOp[pNext->aState[i]]==RE_OP_ACCEPT ){ rc = 1; break; }
+  }
+re_match_end:
+  sqlite3_free(pToFree);
+  return rc;
+}
+
+/* Resize the opcode and argument arrays for an RE under construction.
+*/
+static int re_resize(ReCompiled *p, int N){
+  char *aOp;
+  int *aArg;
+  aOp = sqlite3_realloc(p->aOp, N*sizeof(p->aOp[0]));
+  if( aOp==0 ) return 1;
+  p->aOp = aOp;
+  aArg = sqlite3_realloc(p->aArg, N*sizeof(p->aArg[0]));
+  if( aArg==0 ) return 1;
+  p->aArg = aArg;
+  p->nAlloc = N;
+  return 0;
+}
+
+/* Insert a new opcode and argument into an RE under construction.  The
+** insertion point is just prior to existing opcode iBefore.
+*/
+static int re_insert(ReCompiled *p, int iBefore, int op, int arg){
+  int i;
+  if( p->nAlloc<=p->nState && re_resize(p, p->nAlloc*2) ) return 0;
+  for(i=p->nState; i>iBefore; i--){
+    p->aOp[i] = p->aOp[i-1];
+    p->aArg[i] = p->aArg[i-1];
+  }
+  p->nState++;
+  p->aOp[iBefore] = op;
+  p->aArg[iBefore] = arg;
+  return iBefore;
+}
+
+/* Append a new opcode and argument to the end of the RE under construction.
+*/
+static int re_append(ReCompiled *p, int op, int arg){
+  return re_insert(p, p->nState, op, arg);
+}
+
+/* Make a copy of N opcodes starting at iStart onto the end of the RE
+** under construction.
+*/
+static void re_copy(ReCompiled *p, int iStart, int N){
+  if( p->nState+N>=p->nAlloc && re_resize(p, p->nAlloc*2+N) ) return;
+  memcpy(&p->aOp[p->nState], &p->aOp[iStart], N*sizeof(p->aOp[0]));
+  memcpy(&p->aArg[p->nState], &p->aArg[iStart], N*sizeof(p->aArg[0]));
+  p->nState += N;
+}
+
+/* Return true if c is a hexadecimal digit character:  [0-9a-fA-F]
+** If c is a hex digit, also set *pV = (*pV)*16 + valueof(c).  If
+** c is not a hex digit *pV is unchanged.
+*/
+static int re_hex(int c, int *pV){
+  if( c>='0' && c<='9' ){
+    c -= '0';
+  }else if( c>='a' && c<='f' ){
+    c -= 'a' - 10;
+  }else if( c>='A' && c<='F' ){
+    c -= 'A' - 10;
+  }else{
+    return 0;
+  }
+  *pV = (*pV)*16 + (c & 0xff);
+  return 1;
+}
+
+/* A backslash character has been seen, read the next character and
+** return its interpretation.
+*/
+static unsigned re_esc_char(ReCompiled *p){
+  static const char zEsc[] = "afnrtv\\()*.+?[$^{|}]";
+  static const char zTrans[] = "\a\f\n\r\t\v";
+  int i, v = 0;
+  char c;
+  if( p->sIn.i>=p->sIn.mx ) return 0;
+  c = p->sIn.z[p->sIn.i];
+  if( c=='u' && p->sIn.i+4<p->sIn.mx ){
+    const unsigned char *zIn = p->sIn.z + p->sIn.i;
+    if( re_hex(zIn[1],&v)
+     && re_hex(zIn[2],&v)
+     && re_hex(zIn[3],&v)
+     && re_hex(zIn[4],&v)
+    ){
+      p->sIn.i += 5;
+      return v;
+    }
+  }
+  if( c=='x' && p->sIn.i+2<p->sIn.mx ){
+    const unsigned char *zIn = p->sIn.z + p->sIn.i;
+    if( re_hex(zIn[1],&v)
+     && re_hex(zIn[2],&v)
+    ){
+      p->sIn.i += 3;
+      return v;
+    }
+  }
+  for(i=0; zEsc[i] && zEsc[i]!=c; i++){}
+  if( zEsc[i] ){
+    if( i<6 ) c = zTrans[i];
+    p->sIn.i++;
+  }else{
+    p->zErr = "unknown \\ escape";
+  }
+  return c;
+}
+
+/* Forward declaration */
+static const char *re_subcompile_string(ReCompiled*);
+
+/* Peek at the next byte of input */
+static unsigned char rePeek(ReCompiled *p){
+  return p->sIn.i<p->sIn.mx ? p->sIn.z[p->sIn.i] : 0;
+}
+
+/* Compile RE text into a sequence of opcodes.  Continue up to the
+** first unmatched ")" character, then return.  If an error is found,
+** return a pointer to the error message string.
+*/
+static const char *re_subcompile_re(ReCompiled *p){
+  const char *zErr;
+  int iStart, iEnd, iGoto;
+  iStart = p->nState;
+  zErr = re_subcompile_string(p);
+  if( zErr ) return zErr;
+  while( rePeek(p)=='|' ){
+    iEnd = p->nState;
+    re_insert(p, iStart, RE_OP_FORK, iEnd + 2 - iStart);
+    iGoto = re_append(p, RE_OP_GOTO, 0);
+    p->sIn.i++;
+    zErr = re_subcompile_string(p);
+    if( zErr ) return zErr;
+    p->aArg[iGoto] = p->nState - iGoto;
+  }
+  return 0;
+}
+
+/* Compile an element of regular expression text (anything that can be
+** an operand to the "|" operator).  Return NULL on success or a pointer
+** to the error message if there is a problem.
+*/
+static const char *re_subcompile_string(ReCompiled *p){
+  int iPrev = -1;
+  int iStart;
+  unsigned c;
+  const char *zErr;
+  while( (c = p->xNextChar(&p->sIn))!=0 ){
+    iStart = p->nState;
+    switch( c ){
+      case '|':
+      case '$': 
+      case ')': {
+        p->sIn.i--;
+        return 0;
+      }
+      case '(': {
+        zErr = re_subcompile_re(p);
+        if( zErr ) return zErr;
+        if( rePeek(p)!=')' ) return "unmatched '('";
+        p->sIn.i++;
+        break;
+      }
+      case '.': {
+        if( rePeek(p)=='*' ){
+          re_append(p, RE_OP_ANYSTAR, 0);
+          p->sIn.i++;
+        }else{ 
+          re_append(p, RE_OP_ANY, 0);
+        }
+        break;
+      }
+      case '*': {
+        if( iPrev<0 ) return "'*' without operand";
+        re_insert(p, iPrev, RE_OP_GOTO, p->nState - iPrev + 1);
+        re_append(p, RE_OP_FORK, iPrev - p->nState + 1);
+        break;
+      }
+      case '+': {
+        if( iPrev<0 ) return "'+' without operand";
+        re_append(p, RE_OP_FORK, iPrev - p->nState);
+        break;
+      }
+      case '?': {
+        if( iPrev<0 ) return "'?' without operand";
+        re_insert(p, iPrev, RE_OP_FORK, p->nState - iPrev+1);
+        break;
+      }
+      case '{': {
+        int m = 0, n = 0;
+        int sz, j;
+        if( iPrev<0 ) return "'{m,n}' without operand";
+        while( (c=rePeek(p))>='0' && c<='9' ){ m = m*10 + c - '0'; p->sIn.i++; }
+        n = m;
+        if( c==',' ){
+          p->sIn.i++;
+          n = 0;
+          while( (c=rePeek(p))>='0' && c<='9' ){ n = n*10 + c-'0'; p->sIn.i++; }
+        }
+        if( c!='}' ) return "unmatched '{'";
+        if( n>0 && n<m ) return "n less than m in '{m,n}'";
+        p->sIn.i++;
+        sz = p->nState - iPrev;
+        if( m==0 ){
+          if( n==0 ) return "both m and n are zero in '{m,n}'";
+          re_insert(p, iPrev, RE_OP_FORK, sz+1);
+          n--;
+        }else{
+          for(j=1; j<m; j++) re_copy(p, iPrev, sz);
+        }
+        for(j=m; j<n; j++){
+          re_append(p, RE_OP_FORK, sz+1);
+          re_copy(p, iPrev, sz);
+        }
+        if( n==0 && m>0 ){
+          re_append(p, RE_OP_FORK, -sz);
+        }
+        break;
+      }
+      case '[': {
+        int iFirst = p->nState;
+        if( rePeek(p)=='^' ){
+          re_append(p, RE_OP_CC_EXC, 0);
+          p->sIn.i++;
+        }else{
+          re_append(p, RE_OP_CC_INC, 0);
+        }
+        while( (c = p->xNextChar(&p->sIn))!=0 ){
+          if( c=='[' && rePeek(p)==':' ){
+            return "POSIX character classes not supported";
+          }
+          if( c=='\\' ) c = re_esc_char(p);
+          if( rePeek(p)=='-' ){
+            re_append(p, RE_OP_CC_RANGE, c);
+            p->sIn.i++;
+            c = p->xNextChar(&p->sIn);
+            if( c=='\\' ) c = re_esc_char(p);
+            re_append(p, RE_OP_CC_RANGE, c);
+          }else{
+            re_append(p, RE_OP_CC_VALUE, c);
+          }
+          if( rePeek(p)==']' ){ p->sIn.i++; break; }
+        }
+        if( c==0 ) return "unclosed '['";
+        p->aArg[iFirst] = p->nState - iFirst;
+        break;
+      }
+      case '\\': {
+        int specialOp = 0;
+        switch( rePeek(p) ){
+          case 'b': specialOp = RE_OP_BOUNDARY;   break;
+          case 'd': specialOp = RE_OP_DIGIT;      break;
+          case 'D': specialOp = RE_OP_NOTDIGIT;   break;
+          case 's': specialOp = RE_OP_SPACE;      break;
+          case 'S': specialOp = RE_OP_NOTSPACE;   break;
+          case 'w': specialOp = RE_OP_WORD;       break;
+          case 'W': specialOp = RE_OP_NOTWORD;    break;
+        }
+        if( specialOp ){
+          p->sIn.i++;
+          re_append(p, specialOp, 0);
+        }else{
+          c = re_esc_char(p);
+          re_append(p, RE_OP_MATCH, c);
+        }
+        break;
+      }
+      default: {
+        re_append(p, RE_OP_MATCH, c);
+        break;
+      }
+    }
+    iPrev = iStart;
+  }
+  return 0;
+}
+
+/* Free and reclaim all the memory used by a previously compiled
+** regular expression.  Applications should invoke this routine once
+** for every call to re_compile() to avoid memory leaks.
+*/
+void re_free(ReCompiled *pRe){
+  if( pRe ){
+    sqlite3_free(pRe->aOp);
+    sqlite3_free(pRe->aArg);
+    sqlite3_free(pRe);
+  }
+}
+
+/*
+** Compile a textual regular expression in zIn[] into a compiled regular
+** expression suitable for us by re_match() and return a pointer to the
+** compiled regular expression in *ppRe.  Return NULL on success or an
+** error message if something goes wrong.
+*/
+const char *re_compile(ReCompiled **ppRe, const char *zIn, int noCase){
+  ReCompiled *pRe;
+  const char *zErr;
+  int i, j;
+
+  *ppRe = 0;
+  pRe = sqlite3_malloc( sizeof(*pRe) );
+  if( pRe==0 ){
+    return "out of memory";
+  }
+  memset(pRe, 0, sizeof(*pRe));
+  pRe->xNextChar = noCase ? re_next_char_nocase : re_next_char;
+  if( re_resize(pRe, 30) ){
+    re_free(pRe);
+    return "out of memory";
+  }
+  if( zIn[0]=='^' ){
+    zIn++;
+  }else{
+    re_append(pRe, RE_OP_ANYSTAR, 0);
+  }
+  pRe->sIn.z = (unsigned char*)zIn;
+  pRe->sIn.i = 0;
+  pRe->sIn.mx = (int)strlen(zIn);
+  zErr = re_subcompile_re(pRe);
+  if( zErr ){
+    re_free(pRe);
+    return zErr;
+  }
+  if( rePeek(pRe)=='$' && pRe->sIn.i+1>=pRe->sIn.mx ){
+    re_append(pRe, RE_OP_MATCH, RE_EOF);
+    re_append(pRe, RE_OP_ACCEPT, 0);
+    *ppRe = pRe;
+  }else if( pRe->sIn.i>=pRe->sIn.mx ){
+    re_append(pRe, RE_OP_ACCEPT, 0);
+    *ppRe = pRe;
+  }else{
+    re_free(pRe);
+    return "unrecognized character";
+  }
+
+  /* The following is a performance optimization.  If the regex begins with
+  ** ".*" (if the input regex lacks an initial "^") and afterwards there are
+  ** one or more matching characters, enter those matching characters into
+  ** zInit[].  The re_match() routine can then search ahead in the input 
+  ** string looking for the initial match without having to run the whole
+  ** regex engine over the string.  Do not worry able trying to match
+  ** unicode characters beyond plane 0 - those are very rare and this is
+  ** just an optimization. */
+  if( pRe->aOp[0]==RE_OP_ANYSTAR ){
+    for(j=0, i=1; j<sizeof(pRe->zInit)-2 && pRe->aOp[i]==RE_OP_MATCH; i++){
+      unsigned x = pRe->aArg[i];
+      if( x<=127 ){
+        pRe->zInit[j++] = x;
+      }else if( x<=0xfff ){
+        pRe->zInit[j++] = 0xc0 | (x>>6);
+        pRe->zInit[j++] = 0x80 | (x&0x3f);
+      }else if( x<=0xffff ){
+        pRe->zInit[j++] = 0xd0 | (x>>12);
+        pRe->zInit[j++] = 0x80 | ((x>>6)&0x3f);
+        pRe->zInit[j++] = 0x80 | (x&0x3f);
+      }else{
+        break;
+      }
+    }
+    if( j>0 && pRe->zInit[j-1]==0 ) j--;
+    pRe->nInit = j;
+  }
+  return pRe->zErr;
+}
+
+/*
+** Implementation of the regexp() SQL function.  This function implements
+** the build-in REGEXP operator.  The first argument to the function is the
+** pattern and the second argument is the string.  So, the SQL statements:
+**
+**       A REGEXP B
+**
+** is implemented as regexp(B,A).
+*/
+static void re_sql_func(
+  sqlite3_context *context, 
+  int argc, 
+  sqlite3_value **argv
+){
+  ReCompiled *pRe;          /* Compiled regular expression */
+  const char *zPattern;     /* The regular expression */
+  const unsigned char *zStr;/* String being searched */
+  const char *zErr;         /* Compile error message */
+
+  pRe = sqlite3_get_auxdata(context, 0);
+  if( pRe==0 ){
+    zPattern = (const char*)sqlite3_value_text(argv[0]);
+    if( zPattern==0 ) return;
+    zErr = re_compile(&pRe, zPattern, 0);
+    if( zErr ){
+      re_free(pRe);
+      sqlite3_result_error(context, zErr, -1);
+      return;
+    }
+    if( pRe==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
+    sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
+  }
+  zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
+  if( zStr!=0 ){
+    sqlite3_result_int(context, re_match(pRe, zStr, -1));
+  }
+}
+
+/*
+** Invoke this routine to register the regexp() function with the
+** SQLite database connection.
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_regexp_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  rc = sqlite3_create_function(db, "regexp", 2, SQLITE_UTF8, 0,
+                                 re_sql_func, 0, 0);
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/rot13.c b/lib/libsqlite3/ext/misc/rot13.c
new file mode 100644
index 00000000000..68fdf60b0f0
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/rot13.c
@@ -0,0 +1,114 @@
+/*
+** 2013-05-15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements a rot13() function and a rot13
+** collating sequence.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+/*
+** Perform rot13 encoding on a single ASCII character.
+*/
+static unsigned char rot13(unsigned char c){
+  if( c>='a' && c<='z' ){
+    c += 13;
+    if( c>'z' ) c -= 26;
+  }else if( c>='A' && c<='Z' ){
+    c += 13;
+    if( c>'Z' ) c -= 26;
+  }
+  return c;
+}
+
+/*
+** Implementation of the rot13() function.
+**
+** Rotate ASCII alphabetic characters by 13 character positions.  
+** Non-ASCII characters are unchanged.  rot13(rot13(X)) should always
+** equal X.
+*/
+static void rot13func(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zIn;
+  int nIn;
+  unsigned char *zOut;
+  char *zToFree = 0;
+  int i;
+  char zTemp[100];
+  assert( argc==1 );
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  zIn = (const unsigned char*)sqlite3_value_text(argv[0]);
+  nIn = sqlite3_value_bytes(argv[0]);
+  if( nIn<sizeof(zTemp)-1 ){
+    zOut = zTemp;
+  }else{
+    zOut = zToFree = sqlite3_malloc( nIn+1 );
+    if( zOut==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
+  }
+  for(i=0; i<nIn; i++) zOut[i] = rot13(zIn[i]);
+  zOut[i] = 0;
+  sqlite3_result_text(context, (char*)zOut, i, SQLITE_TRANSIENT);
+  sqlite3_free(zToFree);
+}
+
+/*
+** Implement the rot13 collating sequence so that if
+**
+**      x=y COLLATE rot13
+**
+** Then 
+**
+**      rot13(x)=rot13(y) COLLATE binary
+*/
+static int rot13CollFunc(
+  void *notUsed,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  const char *zA = (const char*)pKey1;
+  const char *zB = (const char*)pKey2;
+  int i, x;
+  for(i=0; i<nKey1 && i<nKey2; i++){
+    x = (int)rot13(zA[i]) - (int)rot13(zB[i]);
+    if( x!=0 ) return x;
+  }
+  return nKey1 - nKey2;
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_rot_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "rot13", 1, SQLITE_UTF8, 0,
+                               rot13func, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_collation(db, "rot13", SQLITE_UTF8, 0, rot13CollFunc);
+  }
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/spellfix.c b/lib/libsqlite3/ext/misc/spellfix.c
new file mode 100644
index 00000000000..eb5442ed2ff
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/spellfix.c
@@ -0,0 +1,2844 @@
+/*
+** 2012 April 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This module implements the spellfix1 VIRTUAL TABLE that can be used
+** to search a large vocabulary for close matches.  See separate
+** documentation (http://www.sqlite.org/spellfix1.html) for details.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+
+#ifndef SQLITE_AMALGAMATION
+# include <string.h>
+# include <stdio.h>
+# include <stdlib.h>
+# include <assert.h>
+# define ALWAYS(X)  1
+# define NEVER(X)   0
+  typedef unsigned char u8;
+  typedef unsigned short u16;
+# include <ctype.h>
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Character classes for ASCII characters:
+**
+**   0   ''        Silent letters:   H W
+**   1   'A'       Any vowel:   A E I O U (Y)
+**   2   'B'       A bilabeal stop or fricative:  B F P V W
+**   3   'C'       Other fricatives or back stops:  C G J K Q S X Z
+**   4   'D'       Alveolar stops:  D T
+**   5   'H'       Letter H at the beginning of a word
+**   6   'L'       Glide:  L
+**   7   'R'       Semivowel:  R
+**   8   'M'       Nasals:  M N
+**   9   'Y'       Letter Y at the beginning of a word.
+**   10  '9'       Digits: 0 1 2 3 4 5 6 7 8 9
+**   11  ' '       White space
+**   12  '?'       Other.
+*/
+#define CCLASS_SILENT         0
+#define CCLASS_VOWEL          1
+#define CCLASS_B              2
+#define CCLASS_C              3
+#define CCLASS_D              4
+#define CCLASS_H              5
+#define CCLASS_L              6
+#define CCLASS_R              7
+#define CCLASS_M              8
+#define CCLASS_Y              9
+#define CCLASS_DIGIT         10
+#define CCLASS_SPACE         11
+#define CCLASS_OTHER         12
+
+/*
+** The following table gives the character class for non-initial ASCII
+** characters.
+*/
+static const unsigned char midClass[] = {
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_SPACE,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_SPACE,    /*   */ CCLASS_SPACE,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_SPACE,
+ /* ! */ CCLASS_OTHER,    /* " */ CCLASS_OTHER,   /* # */ CCLASS_OTHER,
+ /* $ */ CCLASS_OTHER,    /* % */ CCLASS_OTHER,   /* & */ CCLASS_OTHER,
+ /* ' */ CCLASS_SILENT,   /* ( */ CCLASS_OTHER,   /* ) */ CCLASS_OTHER,
+ /* * */ CCLASS_OTHER,    /* + */ CCLASS_OTHER,   /* , */ CCLASS_OTHER,
+ /* - */ CCLASS_OTHER,    /* . */ CCLASS_OTHER,   /* / */ CCLASS_OTHER,
+ /* 0 */ CCLASS_DIGIT,    /* 1 */ CCLASS_DIGIT,   /* 2 */ CCLASS_DIGIT,
+ /* 3 */ CCLASS_DIGIT,    /* 4 */ CCLASS_DIGIT,   /* 5 */ CCLASS_DIGIT,
+ /* 6 */ CCLASS_DIGIT,    /* 7 */ CCLASS_DIGIT,   /* 8 */ CCLASS_DIGIT,
+ /* 9 */ CCLASS_DIGIT,    /* : */ CCLASS_OTHER,   /* ; */ CCLASS_OTHER,
+ /* < */ CCLASS_OTHER,    /* = */ CCLASS_OTHER,   /* > */ CCLASS_OTHER,
+ /* ? */ CCLASS_OTHER,    /* @ */ CCLASS_OTHER,   /* A */ CCLASS_VOWEL,
+ /* B */ CCLASS_B,        /* C */ CCLASS_C,       /* D */ CCLASS_D,
+ /* E */ CCLASS_VOWEL,    /* F */ CCLASS_B,       /* G */ CCLASS_C,
+ /* H */ CCLASS_SILENT,   /* I */ CCLASS_VOWEL,   /* J */ CCLASS_C,
+ /* K */ CCLASS_C,        /* L */ CCLASS_L,       /* M */ CCLASS_M,
+ /* N */ CCLASS_M,        /* O */ CCLASS_VOWEL,   /* P */ CCLASS_B,
+ /* Q */ CCLASS_C,        /* R */ CCLASS_R,       /* S */ CCLASS_C,
+ /* T */ CCLASS_D,        /* U */ CCLASS_VOWEL,   /* V */ CCLASS_B,
+ /* W */ CCLASS_B,        /* X */ CCLASS_C,       /* Y */ CCLASS_VOWEL,
+ /* Z */ CCLASS_C,        /* [ */ CCLASS_OTHER,   /* \ */ CCLASS_OTHER,
+ /* ] */ CCLASS_OTHER,    /* ^ */ CCLASS_OTHER,   /* _ */ CCLASS_OTHER,
+ /* ` */ CCLASS_OTHER,    /* a */ CCLASS_VOWEL,   /* b */ CCLASS_B,
+ /* c */ CCLASS_C,        /* d */ CCLASS_D,       /* e */ CCLASS_VOWEL,
+ /* f */ CCLASS_B,        /* g */ CCLASS_C,       /* h */ CCLASS_SILENT,
+ /* i */ CCLASS_VOWEL,    /* j */ CCLASS_C,       /* k */ CCLASS_C,
+ /* l */ CCLASS_L,        /* m */ CCLASS_M,       /* n */ CCLASS_M,
+ /* o */ CCLASS_VOWEL,    /* p */ CCLASS_B,       /* q */ CCLASS_C,
+ /* r */ CCLASS_R,        /* s */ CCLASS_C,       /* t */ CCLASS_D,
+ /* u */ CCLASS_VOWEL,    /* v */ CCLASS_B,       /* w */ CCLASS_B,
+ /* x */ CCLASS_C,        /* y */ CCLASS_VOWEL,   /* z */ CCLASS_C,
+ /* { */ CCLASS_OTHER,    /* | */ CCLASS_OTHER,   /* } */ CCLASS_OTHER,
+ /* ~ */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   
+};
+/* 
+** This tables gives the character class for ASCII characters that form the
+** initial character of a word.  The only difference from midClass is with
+** the letters H, W, and Y.
+*/
+static const unsigned char initClass[] = {
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_SPACE,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_SPACE,    /*   */ CCLASS_SPACE,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_OTHER,
+ /*   */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   /*   */ CCLASS_SPACE,
+ /* ! */ CCLASS_OTHER,    /* " */ CCLASS_OTHER,   /* # */ CCLASS_OTHER,
+ /* $ */ CCLASS_OTHER,    /* % */ CCLASS_OTHER,   /* & */ CCLASS_OTHER,
+ /* ' */ CCLASS_OTHER,    /* ( */ CCLASS_OTHER,   /* ) */ CCLASS_OTHER,
+ /* * */ CCLASS_OTHER,    /* + */ CCLASS_OTHER,   /* , */ CCLASS_OTHER,
+ /* - */ CCLASS_OTHER,    /* . */ CCLASS_OTHER,   /* / */ CCLASS_OTHER,
+ /* 0 */ CCLASS_DIGIT,    /* 1 */ CCLASS_DIGIT,   /* 2 */ CCLASS_DIGIT,
+ /* 3 */ CCLASS_DIGIT,    /* 4 */ CCLASS_DIGIT,   /* 5 */ CCLASS_DIGIT,
+ /* 6 */ CCLASS_DIGIT,    /* 7 */ CCLASS_DIGIT,   /* 8 */ CCLASS_DIGIT,
+ /* 9 */ CCLASS_DIGIT,    /* : */ CCLASS_OTHER,   /* ; */ CCLASS_OTHER,
+ /* < */ CCLASS_OTHER,    /* = */ CCLASS_OTHER,   /* > */ CCLASS_OTHER,
+ /* ? */ CCLASS_OTHER,    /* @ */ CCLASS_OTHER,   /* A */ CCLASS_VOWEL,
+ /* B */ CCLASS_B,        /* C */ CCLASS_C,       /* D */ CCLASS_D,
+ /* E */ CCLASS_VOWEL,    /* F */ CCLASS_B,       /* G */ CCLASS_C,
+ /* H */ CCLASS_SILENT,   /* I */ CCLASS_VOWEL,   /* J */ CCLASS_C,
+ /* K */ CCLASS_C,        /* L */ CCLASS_L,       /* M */ CCLASS_M,
+ /* N */ CCLASS_M,        /* O */ CCLASS_VOWEL,   /* P */ CCLASS_B,
+ /* Q */ CCLASS_C,        /* R */ CCLASS_R,       /* S */ CCLASS_C,
+ /* T */ CCLASS_D,        /* U */ CCLASS_VOWEL,   /* V */ CCLASS_B,
+ /* W */ CCLASS_B,        /* X */ CCLASS_C,       /* Y */ CCLASS_Y,
+ /* Z */ CCLASS_C,        /* [ */ CCLASS_OTHER,   /* \ */ CCLASS_OTHER,
+ /* ] */ CCLASS_OTHER,    /* ^ */ CCLASS_OTHER,   /* _ */ CCLASS_OTHER,
+ /* ` */ CCLASS_OTHER,    /* a */ CCLASS_VOWEL,   /* b */ CCLASS_B,
+ /* c */ CCLASS_C,        /* d */ CCLASS_D,       /* e */ CCLASS_VOWEL,
+ /* f */ CCLASS_B,        /* g */ CCLASS_C,       /* h */ CCLASS_SILENT,
+ /* i */ CCLASS_VOWEL,    /* j */ CCLASS_C,       /* k */ CCLASS_C,
+ /* l */ CCLASS_L,        /* m */ CCLASS_M,       /* n */ CCLASS_M,
+ /* o */ CCLASS_VOWEL,    /* p */ CCLASS_B,       /* q */ CCLASS_C,
+ /* r */ CCLASS_R,        /* s */ CCLASS_C,       /* t */ CCLASS_D,
+ /* u */ CCLASS_VOWEL,    /* v */ CCLASS_B,       /* w */ CCLASS_B,
+ /* x */ CCLASS_C,        /* y */ CCLASS_Y,       /* z */ CCLASS_C,
+ /* { */ CCLASS_OTHER,    /* | */ CCLASS_OTHER,   /* } */ CCLASS_OTHER,
+ /* ~ */ CCLASS_OTHER,    /*   */ CCLASS_OTHER,   
+};
+
+/*
+** Mapping from the character class number (0-13) to a symbol for each
+** character class.  Note that initClass[] can be used to map the class
+** symbol back into the class number.
+*/
+static const unsigned char className[] = ".ABCDHLRMY9 ?";
+
+/*
+** Generate a "phonetic hash" from a string of ASCII characters
+** in zIn[0..nIn-1].
+**
+**   * Map characters by character class as defined above.
+**   * Omit double-letters
+**   * Omit vowels beside R and L
+**   * Omit T when followed by CH
+**   * Omit W when followed by R
+**   * Omit D when followed by J or G
+**   * Omit K in KN or G in GN at the beginning of a word
+**
+** Space to hold the result is obtained from sqlite3_malloc()
+**
+** Return NULL if memory allocation fails.  
+*/
+static unsigned char *phoneticHash(const unsigned char *zIn, int nIn){
+  unsigned char *zOut = sqlite3_malloc( nIn + 1 );
+  int i;
+  int nOut = 0;
+  char cPrev = 0x77;
+  char cPrevX = 0x77;
+  const unsigned char *aClass = initClass;
+
+  if( zOut==0 ) return 0;
+  if( nIn>2 ){
+    switch( zIn[0] ){
+      case 'g': 
+      case 'k': {
+        if( zIn[1]=='n' ){ zIn++; nIn--; }
+        break;
+      }
+    }
+  }
+  for(i=0; i<nIn; i++){
+    unsigned char c = zIn[i];
+    if( i+1<nIn ){
+      if( c=='w' && zIn[i+1]=='r' ) continue;
+      if( c=='d' && (zIn[i+1]=='j' || zIn[i+1]=='g') ) continue;
+      if( i+2<nIn ){
+        if( c=='t' && zIn[i+1]=='c' && zIn[i+2]=='h' ) continue;
+      }
+    }
+    c = aClass[c&0x7f];
+    if( c==CCLASS_SPACE ) continue;
+    if( c==CCLASS_OTHER && cPrev!=CCLASS_DIGIT ) continue;
+    aClass = midClass;
+    if( c==CCLASS_VOWEL && (cPrevX==CCLASS_R || cPrevX==CCLASS_L) ){
+       continue; /* No vowels beside L or R */ 
+    }
+    if( (c==CCLASS_R || c==CCLASS_L) && cPrevX==CCLASS_VOWEL ){
+       nOut--;   /* No vowels beside L or R */
+    }
+    cPrev = c;
+    if( c==CCLASS_SILENT ) continue;
+    cPrevX = c;
+    c = className[c];
+    assert( nOut>=0 );
+    if( nOut==0 || c!=zOut[nOut-1] ) zOut[nOut++] = c;
+  }
+  zOut[nOut] = 0;
+  return zOut;
+}
+
+/*
+** This is an SQL function wrapper around phoneticHash().  See
+** the description of phoneticHash() for additional information.
+*/
+static void phoneticHashSqlFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zIn;
+  unsigned char *zOut;
+
+  zIn = sqlite3_value_text(argv[0]);
+  if( zIn==0 ) return;
+  zOut = phoneticHash(zIn, sqlite3_value_bytes(argv[0]));
+  if( zOut==0 ){
+    sqlite3_result_error_nomem(context);
+  }else{
+    sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free);
+  }
+}
+
+/*
+** Return the character class number for a character given its
+** context.
+*/
+static char characterClass(char cPrev, char c){
+  return cPrev==0 ? initClass[c&0x7f] : midClass[c&0x7f];
+}
+
+/*
+** Return the cost of inserting or deleting character c immediately
+** following character cPrev.  If cPrev==0, that means c is the first
+** character of the word.
+*/
+static int insertOrDeleteCost(char cPrev, char c, char cNext){
+  char classC = characterClass(cPrev, c);
+  char classCprev;
+
+  if( classC==CCLASS_SILENT ){
+    /* Insert or delete "silent" characters such as H or W */
+    return 1;
+  }
+  if( cPrev==c ){
+    /* Repeated characters, or miss a repeat */
+    return 10;
+  }
+  if( classC==CCLASS_VOWEL && (cPrev=='r' || cNext=='r') ){
+    return 20;  /* Insert a vowel before or after 'r' */
+  }
+  classCprev = characterClass(cPrev, cPrev);
+  if( classC==classCprev ){
+    if( classC==CCLASS_VOWEL ){
+      /* Remove or add a new vowel to a vowel cluster */
+      return 15;
+    }else{
+      /* Remove or add a consonant not in the same class */
+      return 50;
+    }
+  }
+
+  /* any other character insertion or deletion */
+  return 100;
+}
+
+/*
+** Divide the insertion cost by this factor when appending to the
+** end of the word.
+*/
+#define FINAL_INS_COST_DIV  4
+
+/*
+** Return the cost of substituting cTo in place of cFrom assuming
+** the previous character is cPrev.  If cPrev==0 then cTo is the first
+** character of the word.
+*/
+static int substituteCost(char cPrev, char cFrom, char cTo){
+  char classFrom, classTo;
+  if( cFrom==cTo ){
+    /* Exact match */
+    return 0;
+  }
+  if( cFrom==(cTo^0x20) && ((cTo>='A' && cTo<='Z') || (cTo>='a' && cTo<='z')) ){
+    /* differ only in case */
+    return 0;
+  }
+  classFrom = characterClass(cPrev, cFrom);
+  classTo = characterClass(cPrev, cTo);
+  if( classFrom==classTo ){
+    /* Same character class */
+    return 40;
+  }
+  if( classFrom>=CCLASS_B && classFrom<=CCLASS_Y
+      && classTo>=CCLASS_B && classTo<=CCLASS_Y ){
+    /* Convert from one consonant to another, but in a different class */
+    return 75;
+  }
+  /* Any other subsitution */
+  return 100;
+}
+
+/*
+** Given two strings zA and zB which are pure ASCII, return the cost
+** of transforming zA into zB.  If zA ends with '*' assume that it is
+** a prefix of zB and give only minimal penalty for extra characters
+** on the end of zB.
+**
+** Smaller numbers mean a closer match.
+**
+** Negative values indicate an error:
+**    -1  One of the inputs is NULL
+**    -2  Non-ASCII characters on input
+**    -3  Unable to allocate memory 
+**
+** If pnMatch is not NULL, then *pnMatch is set to the number of bytes
+** of zB that matched the pattern in zA. If zA does not end with a '*',
+** then this value is always the number of bytes in zB (i.e. strlen(zB)).
+** If zA does end in a '*', then it is the number of bytes in the prefix
+** of zB that was deemed to match zA.
+*/
+static int editdist1(const char *zA, const char *zB, int *pnMatch){
+  int nA, nB;            /* Number of characters in zA[] and zB[] */
+  int xA, xB;            /* Loop counters for zA[] and zB[] */
+  char cA, cB;           /* Current character of zA and zB */
+  char cAprev, cBprev;   /* Previous character of zA and zB */
+  char cAnext, cBnext;   /* Next character in zA and zB */
+  int d;                 /* North-west cost value */
+  int dc = 0;            /* North-west character value */
+  int res;               /* Final result */
+  int *m;                /* The cost matrix */
+  char *cx;              /* Corresponding character values */
+  int *toFree = 0;       /* Malloced space */
+  int mStack[60+15];     /* Stack space to use if not too much is needed */
+  int nMatch = 0;
+
+  /* Early out if either input is NULL */
+  if( zA==0 || zB==0 ) return -1;
+
+  /* Skip any common prefix */
+  while( zA[0] && zA[0]==zB[0] ){ dc = zA[0]; zA++; zB++; nMatch++; }
+  if( pnMatch ) *pnMatch = nMatch;
+  if( zA[0]==0 && zB[0]==0 ) return 0;
+
+#if 0
+  printf("A=\"%s\" B=\"%s\" dc=%c\n", zA, zB, dc?dc:' ');
+#endif
+
+  /* Verify input strings and measure their lengths */
+  for(nA=0; zA[nA]; nA++){
+    if( zA[nA]&0x80 ) return -2;
+  }
+  for(nB=0; zB[nB]; nB++){
+    if( zB[nB]&0x80 ) return -2;
+  }
+
+  /* Special processing if either string is empty */
+  if( nA==0 ){
+    cBprev = dc;
+    for(xB=res=0; (cB = zB[xB])!=0; xB++){
+      res += insertOrDeleteCost(cBprev, cB, zB[xB+1])/FINAL_INS_COST_DIV;
+      cBprev = cB;
+    }
+    return res;
+  }
+  if( nB==0 ){
+    cAprev = dc;
+    for(xA=res=0; (cA = zA[xA])!=0; xA++){
+      res += insertOrDeleteCost(cAprev, cA, zA[xA+1]);
+      cAprev = cA;
+    }
+    return res;
+  }
+
+  /* A is a prefix of B */
+  if( zA[0]=='*' && zA[1]==0 ) return 0;
+
+  /* Allocate and initialize the Wagner matrix */
+  if( nB<(sizeof(mStack)*4)/(sizeof(mStack[0])*5) ){
+    m = mStack;
+  }else{
+    m = toFree = sqlite3_malloc( (nB+1)*5*sizeof(m[0])/4 );
+    if( m==0 ) return -3;
+  }
+  cx = (char*)&m[nB+1];
+
+  /* Compute the Wagner edit distance */
+  m[0] = 0;
+  cx[0] = dc;
+  cBprev = dc;
+  for(xB=1; xB<=nB; xB++){
+    cBnext = zB[xB];
+    cB = zB[xB-1];
+    cx[xB] = cB;
+    m[xB] = m[xB-1] + insertOrDeleteCost(cBprev, cB, cBnext);
+    cBprev = cB;
+  }
+  cAprev = dc;
+  for(xA=1; xA<=nA; xA++){
+    int lastA = (xA==nA);
+    cA = zA[xA-1];
+    cAnext = zA[xA];
+    if( cA=='*' && lastA ) break;
+    d = m[0];
+    dc = cx[0];
+    m[0] = d + insertOrDeleteCost(cAprev, cA, cAnext);
+    cBprev = 0;
+    for(xB=1; xB<=nB; xB++){
+      int totalCost, insCost, delCost, subCost, ncx;
+      cB = zB[xB-1];
+      cBnext = zB[xB];
+
+      /* Cost to insert cB */
+      insCost = insertOrDeleteCost(cx[xB-1], cB, cBnext);
+      if( lastA ) insCost /= FINAL_INS_COST_DIV;
+
+      /* Cost to delete cA */
+      delCost = insertOrDeleteCost(cx[xB], cA, cBnext);
+
+      /* Cost to substitute cA->cB */
+      subCost = substituteCost(cx[xB-1], cA, cB);
+
+      /* Best cost */
+      totalCost = insCost + m[xB-1];
+      ncx = cB;
+      if( (delCost + m[xB])<totalCost ){
+        totalCost = delCost + m[xB];
+        ncx = cA;
+      }
+      if( (subCost + d)<totalCost ){
+        totalCost = subCost + d;
+      }
+
+#if 0
+      printf("%d,%d d=%4d u=%4d r=%4d dc=%c cA=%c cB=%c"
+             " ins=%4d del=%4d sub=%4d t=%4d ncx=%c\n",
+             xA, xB, d, m[xB], m[xB-1], dc?dc:' ', cA, cB,
+             insCost, delCost, subCost, totalCost, ncx?ncx:' ');
+#endif
+
+      /* Update the matrix */
+      d = m[xB];
+      dc = cx[xB];
+      m[xB] = totalCost;
+      cx[xB] = ncx;
+      cBprev = cB;
+    }
+    cAprev = cA;
+  }
+
+  /* Free the wagner matrix and return the result */
+  if( cA=='*' ){
+    res = m[1];
+    for(xB=1; xB<=nB; xB++){
+      if( m[xB]<res ){
+        res = m[xB];
+        if( pnMatch ) *pnMatch = xB+nMatch;
+      }
+    }
+  }else{
+    res = m[nB];
+    /* In the current implementation, pnMatch is always NULL if zA does
+    ** not end in "*" */
+    assert( pnMatch==0 );
+  }
+  sqlite3_free(toFree);
+  return res;
+}
+
+/*
+** Function:    editdist(A,B)
+**
+** Return the cost of transforming string A into string B.  Both strings
+** must be pure ASCII text.  If A ends with '*' then it is assumed to be
+** a prefix of B and extra characters on the end of B have minimal additional
+** cost.
+*/
+static void editdistSqlFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int res = editdist1(
+                    (const char*)sqlite3_value_text(argv[0]),
+                    (const char*)sqlite3_value_text(argv[1]),
+                    0);
+  if( res<0 ){
+    if( res==(-3) ){
+      sqlite3_result_error_nomem(context);
+    }else if( res==(-2) ){
+      sqlite3_result_error(context, "non-ASCII input to editdist()", -1);
+    }else{
+      sqlite3_result_error(context, "NULL input to editdist()", -1);
+    }
+  }else{ 
+    sqlite3_result_int(context, res);
+  }
+}
+
+/* End of the fixed-cost edit distance implementation
+******************************************************************************
+*****************************************************************************
+** Begin: Configurable cost unicode edit distance routines
+*/
+/* Forward declaration of structures */
+typedef struct EditDist3Cost EditDist3Cost;
+typedef struct EditDist3Config EditDist3Config;
+typedef struct EditDist3Point EditDist3Point;
+typedef struct EditDist3From EditDist3From;
+typedef struct EditDist3FromString EditDist3FromString;
+typedef struct EditDist3To EditDist3To;
+typedef struct EditDist3ToString EditDist3ToString;
+typedef struct EditDist3Lang EditDist3Lang;
+
+
+/*
+** An entry in the edit cost table
+*/
+struct EditDist3Cost {
+  EditDist3Cost *pNext;     /* Next cost element */
+  u8 nFrom;                 /* Number of bytes in aFrom */
+  u8 nTo;                   /* Number of bytes in aTo */
+  u16 iCost;                /* Cost of this transformation */
+  char a[4]    ;            /* FROM string followed by TO string */
+  /* Additional TO and FROM string bytes appended as necessary */
+};
+
+/*
+** Edit costs for a particular language ID 
+*/
+struct EditDist3Lang {
+  int iLang;             /* Language ID */
+  int iInsCost;          /* Default insertion cost */
+  int iDelCost;          /* Default deletion cost */
+  int iSubCost;          /* Default substitution cost */
+  EditDist3Cost *pCost;  /* Costs */
+};
+
+
+/*
+** The default EditDist3Lang object, with default costs.
+*/
+static const EditDist3Lang editDist3Lang = { 0, 100, 100, 150, 0 };
+
+/*
+** Complete configuration
+*/
+struct EditDist3Config {
+  int nLang;             /* Number of language IDs.  Size of a[] */
+  EditDist3Lang *a;      /* One for each distinct language ID */
+};
+
+/*
+** Extra information about each character in the FROM string.
+*/
+struct EditDist3From {
+  int nSubst;              /* Number of substitution cost entries */
+  int nDel;                /* Number of deletion cost entries */
+  int nByte;               /* Number of bytes in this character */
+  EditDist3Cost **apSubst; /* Array of substitution costs for this element */
+  EditDist3Cost **apDel;   /* Array of deletion cost entries */
+};
+
+/*
+** A precompiled FROM string.
+*
+** In the common case we expect the FROM string to be reused multiple times.
+** In other words, the common case will be to measure the edit distance
+** from a single origin string to multiple target strings.
+*/
+struct EditDist3FromString {
+  char *z;                 /* The complete text of the FROM string */
+  int n;                   /* Number of characters in the FROM string */
+  int isPrefix;            /* True if ends with '*' character */
+  EditDist3From *a;        /* Extra info about each char of the FROM string */
+};
+
+/*
+** Extra information about each character in the TO string.
+*/
+struct EditDist3To {
+  int nIns;                /* Number of insertion cost entries */
+  int nByte;               /* Number of bytes in this character */
+  EditDist3Cost **apIns;   /* Array of deletion cost entries */
+};
+
+/*
+** A precompiled FROM string
+*/
+struct EditDist3ToString {
+  char *z;                 /* The complete text of the TO string */
+  int n;                   /* Number of characters in the TO string */
+  EditDist3To *a;          /* Extra info about each char of the TO string */
+};
+
+/*
+** Clear or delete an instance of the object that records all edit-distance
+** weights.
+*/
+static void editDist3ConfigClear(EditDist3Config *p){
+  int i;
+  if( p==0 ) return;
+  for(i=0; i<p->nLang; i++){
+    EditDist3Cost *pCost, *pNext;
+    pCost = p->a[i].pCost;
+    while( pCost ){
+      pNext = pCost->pNext;
+      sqlite3_free(pCost);
+      pCost = pNext;
+    }
+  }
+  sqlite3_free(p->a);
+  memset(p, 0, sizeof(*p));
+}
+static void editDist3ConfigDelete(void *pIn){
+  EditDist3Config *p = (EditDist3Config*)pIn;
+  editDist3ConfigClear(p);
+  sqlite3_free(p);
+}
+
+/*
+** Load all edit-distance weights from a table.
+*/
+static int editDist3ConfigLoad(
+  EditDist3Config *p,      /* The edit distance configuration to load */
+  sqlite3 *db,            /* Load from this database */
+  const char *zTable      /* Name of the table from which to load */
+){
+  sqlite3_stmt *pStmt;
+  int rc, rc2;
+  char *zSql;
+  int iLangPrev = -9999;
+  EditDist3Lang *pLang = 0;
+
+  zSql = sqlite3_mprintf("SELECT iLang, cFrom, cTo, iCost"
+                         " FROM \"%w\" WHERE iLang>=0 ORDER BY iLang", zTable);
+  if( zSql==0 ) return SQLITE_NOMEM;
+  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+  sqlite3_free(zSql);
+  if( rc ) return rc;
+  editDist3ConfigClear(p);
+  while( sqlite3_step(pStmt)==SQLITE_ROW ){
+    int iLang = sqlite3_column_int(pStmt, 0);
+    const char *zFrom = (const char*)sqlite3_column_text(pStmt, 1);
+    int nFrom = zFrom ? sqlite3_column_bytes(pStmt, 1) : 0;
+    const char *zTo = (const char*)sqlite3_column_text(pStmt, 2);
+    int nTo = zTo ? sqlite3_column_bytes(pStmt, 2) : 0;
+    int iCost = sqlite3_column_int(pStmt, 3);
+
+    assert( zFrom!=0 || nFrom==0 );
+    assert( zTo!=0 || nTo==0 );
+    if( nFrom>100 || nTo>100 ) continue;
+    if( iCost<0 ) continue;
+    if( pLang==0 || iLang!=iLangPrev ){
+      EditDist3Lang *pNew;
+      pNew = sqlite3_realloc(p->a, (p->nLang+1)*sizeof(p->a[0]));
+      if( pNew==0 ){ rc = SQLITE_NOMEM; break; }
+      p->a = pNew;
+      pLang = &p->a[p->nLang];
+      p->nLang++;
+      pLang->iLang = iLang;
+      pLang->iInsCost = 100;
+      pLang->iDelCost = 100;
+      pLang->iSubCost = 150;
+      pLang->pCost = 0;
+      iLangPrev = iLang;
+    }
+    if( nFrom==1 && zFrom[0]=='?' && nTo==0 ){
+      pLang->iDelCost = iCost;
+    }else if( nFrom==0 && nTo==1 && zTo[0]=='?' ){
+      pLang->iInsCost = iCost;
+    }else if( nFrom==1 && nTo==1 && zFrom[0]=='?' && zTo[0]=='?' ){
+      pLang->iSubCost = iCost;
+    }else{
+      EditDist3Cost *pCost;
+      int nExtra = nFrom + nTo - 4;
+      if( nExtra<0 ) nExtra = 0;
+      pCost = sqlite3_malloc( sizeof(*pCost) + nExtra );
+      if( pCost==0 ){ rc = SQLITE_NOMEM; break; }
+      pCost->nFrom = nFrom;
+      pCost->nTo = nTo;
+      pCost->iCost = iCost;
+      memcpy(pCost->a, zFrom, nFrom);
+      memcpy(pCost->a + nFrom, zTo, nTo);
+      pCost->pNext = pLang->pCost;
+      pLang->pCost = pCost; 
+    }
+  }
+  rc2 = sqlite3_finalize(pStmt);
+  if( rc==SQLITE_OK ) rc = rc2;
+  return rc;
+}
+
+/*
+** Return the length (in bytes) of a utf-8 character.  Or return a maximum
+** of N.
+*/
+static int utf8Len(unsigned char c, int N){
+  int len = 1;
+  if( c>0x7f ){
+    if( (c&0xe0)==0xc0 ){
+      len = 2;
+    }else if( (c&0xf0)==0xe0 ){
+      len = 3;
+    }else{
+      len = 4;
+    }
+  }
+  if( len>N ) len = N;
+  return len;
+}
+
+/*
+** Return TRUE (non-zero) if the To side of the given cost matches
+** the given string.
+*/
+static int matchTo(EditDist3Cost *p, const char *z, int n){
+  if( p->nTo>n ) return 0;
+  if( strncmp(p->a+p->nFrom, z, p->nTo)!=0 ) return 0;
+  return 1;
+}
+
+/*
+** Return TRUE (non-zero) if the From side of the given cost matches
+** the given string.
+*/
+static int matchFrom(EditDist3Cost *p, const char *z, int n){
+  assert( p->nFrom<=n );
+  if( strncmp(p->a, z, p->nFrom)!=0 ) return 0;
+  return 1;
+}
+
+/*
+** Return TRUE (non-zero) of the next FROM character and the next TO
+** character are the same.
+*/
+static int matchFromTo(
+  EditDist3FromString *pStr,  /* Left hand string */
+  int n1,                     /* Index of comparison character on the left */
+  const char *z2,             /* Right-handl comparison character */
+  int n2                      /* Bytes remaining in z2[] */
+){
+  int b1 = pStr->a[n1].nByte;
+  if( b1>n2 ) return 0;
+  if( memcmp(pStr->z+n1, z2, b1)!=0 ) return 0;
+  return 1;
+}
+
+/*
+** Delete an EditDist3FromString objecct
+*/
+static void editDist3FromStringDelete(EditDist3FromString *p){
+  int i;
+  if( p ){
+    for(i=0; i<p->n; i++){
+      sqlite3_free(p->a[i].apDel);
+      sqlite3_free(p->a[i].apSubst);
+    }
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Create a EditDist3FromString object.
+*/
+static EditDist3FromString *editDist3FromStringNew(
+  const EditDist3Lang *pLang,
+  const char *z,
+  int n
+){
+  EditDist3FromString *pStr;
+  EditDist3Cost *p;
+  int i;
+
+  if( z==0 ) return 0;
+  if( n<0 ) n = (int)strlen(z);
+  pStr = sqlite3_malloc( sizeof(*pStr) + sizeof(pStr->a[0])*n + n + 1 );
+  if( pStr==0 ) return 0;
+  pStr->a = (EditDist3From*)&pStr[1];
+  memset(pStr->a, 0, sizeof(pStr->a[0])*n);
+  pStr->n = n;
+  pStr->z = (char*)&pStr->a[n];
+  memcpy(pStr->z, z, n+1);
+  if( n && z[n-1]=='*' ){
+    pStr->isPrefix = 1;
+    n--;
+    pStr->n--;
+    pStr->z[n] = 0;
+  }else{
+    pStr->isPrefix = 0;
+  }
+
+  for(i=0; i<n; i++){
+    EditDist3From *pFrom = &pStr->a[i];
+    memset(pFrom, 0, sizeof(*pFrom));
+    pFrom->nByte = utf8Len((unsigned char)z[i], n-i);
+    for(p=pLang->pCost; p; p=p->pNext){
+      EditDist3Cost **apNew;
+      if( i+p->nFrom>n ) continue;
+      if( matchFrom(p, z+i, n-i)==0 ) continue;
+      if( p->nTo==0 ){
+        apNew = sqlite3_realloc(pFrom->apDel,
+                                sizeof(*apNew)*(pFrom->nDel+1));
+        if( apNew==0 ) break;
+        pFrom->apDel = apNew;
+        apNew[pFrom->nDel++] = p;
+      }else{
+        apNew = sqlite3_realloc(pFrom->apSubst,
+                                sizeof(*apNew)*(pFrom->nSubst+1));
+        if( apNew==0 ) break;
+        pFrom->apSubst = apNew;
+        apNew[pFrom->nSubst++] = p;
+      }
+    }
+    if( p ){
+      editDist3FromStringDelete(pStr);
+      pStr = 0;
+      break;
+    }
+  }
+  return pStr;
+}
+
+/*
+** Update entry m[i] such that it is the minimum of its current value
+** and m[j]+iCost.
+**
+** If the iCost is 1,000,000 or greater, then consider the cost to be
+** infinite and skip the update.
+*/
+static void updateCost(
+  unsigned int *m,
+  int i,
+  int j,
+  int iCost
+){
+  assert( iCost>=0 );
+  if( iCost<10000 ){
+    unsigned int b = m[j] + iCost;
+    if( b<m[i] ) m[i] = b;
+  }
+}
+
+/* Compute the edit distance between two strings.
+**
+** If an error occurs, return a negative number which is the error code.
+**
+** If pnMatch is not NULL, then *pnMatch is set to the number of characters
+** (not bytes) in z2 that matched the search pattern in *pFrom. If pFrom does
+** not contain the pattern for a prefix-search, then this is always the number
+** of characters in z2. If pFrom does contain a prefix search pattern, then
+** it is the number of characters in the prefix of z2 that was deemed to 
+** match pFrom.
+*/
+static int editDist3Core(
+  EditDist3FromString *pFrom,  /* The FROM string */
+  const char *z2,              /* The TO string */
+  int n2,                      /* Length of the TO string */
+  const EditDist3Lang *pLang,  /* Edit weights for a particular language ID */
+  int *pnMatch                 /* OUT: Characters in matched prefix */
+){
+  int k, n;
+  int i1, b1;
+  int i2, b2;
+  EditDist3FromString f = *pFrom;
+  EditDist3To *a2;
+  unsigned int *m;
+  int szRow;
+  EditDist3Cost *p;
+  int res;
+
+  /* allocate the Wagner matrix and the aTo[] array for the TO string */
+  n = (f.n+1)*(n2+1);
+  n = (n+1)&~1;
+  m = sqlite3_malloc( n*sizeof(m[0]) + sizeof(a2[0])*n2 );
+  if( m==0 ) return -1;            /* Out of memory */
+  a2 = (EditDist3To*)&m[n];
+  memset(a2, 0, sizeof(a2[0])*n2);
+
+  /* Fill in the a1[] matrix for all characters of the TO string */
+  for(i2=0; i2<n2; i2++){
+    a2[i2].nByte = utf8Len((unsigned char)z2[i2], n2-i2);
+    for(p=pLang->pCost; p; p=p->pNext){
+      EditDist3Cost **apNew;
+      if( p->nFrom>0 ) continue;
+      if( i2+p->nTo>n2 ) continue;
+      if( matchTo(p, z2+i2, n2-i2)==0 ) continue;
+      a2[i2].nIns++;
+      apNew = sqlite3_realloc(a2[i2].apIns, sizeof(*apNew)*a2[i2].nIns);
+      if( apNew==0 ){
+        res = -1;  /* Out of memory */
+        goto editDist3Abort;
+      }
+      a2[i2].apIns = apNew;
+      a2[i2].apIns[a2[i2].nIns-1] = p;
+    }
+  }
+
+  /* Prepare to compute the minimum edit distance */
+  szRow = f.n+1;
+  memset(m, 0x01, (n2+1)*szRow*sizeof(m[0]));
+  m[0] = 0;
+
+  /* First fill in the top-row of the matrix with FROM deletion costs */
+  for(i1=0; i1<f.n; i1 += b1){
+    b1 = f.a[i1].nByte;
+    updateCost(m, i1+b1, i1, pLang->iDelCost);
+    for(k=0; k<f.a[i1].nDel; k++){
+      p = f.a[i1].apDel[k];
+      updateCost(m, i1+p->nFrom, i1, p->iCost);
+    }
+  }
+
+  /* Fill in all subsequent rows, top-to-bottom, left-to-right */
+  for(i2=0; i2<n2; i2 += b2){
+    int rx;      /* Starting index for current row */
+    int rxp;     /* Starting index for previous row */
+    b2 = a2[i2].nByte;
+    rx = szRow*(i2+b2);
+    rxp = szRow*i2;
+    updateCost(m, rx, rxp, pLang->iInsCost);
+    for(k=0; k<a2[i2].nIns; k++){
+      p = a2[i2].apIns[k];
+      updateCost(m, szRow*(i2+p->nTo), rxp, p->iCost);
+    }
+    for(i1=0; i1<f.n; i1+=b1){
+      int cx;    /* Index of current cell */
+      int cxp;   /* Index of cell immediately to the left */
+      int cxd;   /* Index of cell to the left and one row above */
+      int cxu;   /* Index of cell immediately above */
+      b1 = f.a[i1].nByte;
+      cxp = rx + i1;
+      cx = cxp + b1;
+      cxd = rxp + i1;
+      cxu = cxd + b1;
+      updateCost(m, cx, cxp, pLang->iDelCost);
+      for(k=0; k<f.a[i1].nDel; k++){
+        p = f.a[i1].apDel[k];
+        updateCost(m, cxp+p->nFrom, cxp, p->iCost);
+      }
+      updateCost(m, cx, cxu, pLang->iInsCost);
+      if( matchFromTo(&f, i1, z2+i2, n2-i2) ){
+        updateCost(m, cx, cxd, 0);
+      }
+      updateCost(m, cx, cxd, pLang->iSubCost);
+      for(k=0; k<f.a[i1].nSubst; k++){
+        p = f.a[i1].apSubst[k];
+        if( matchTo(p, z2+i2, n2-i2) ){
+          updateCost(m, cxd+p->nFrom+szRow*p->nTo, cxd, p->iCost);
+        }
+      }
+    }
+  }
+
+#if 0  /* Enable for debugging */
+  printf("         ^");
+  for(i1=0; i1<f.n; i1++) printf(" %c-%2x", f.z[i1], f.z[i1]&0xff);
+  printf("\n   ^:");
+  for(i1=0; i1<szRow; i1++){
+    int v = m[i1];
+    if( v>9999 ) printf(" ****");
+    else         printf(" %4d", v);
+  }
+  printf("\n");
+  for(i2=0; i2<n2; i2++){
+    printf("%c-%02x:", z2[i2], z2[i2]&0xff);
+    for(i1=0; i1<szRow; i1++){
+      int v = m[(i2+1)*szRow+i1];
+      if( v>9999 ) printf(" ****");
+      else         printf(" %4d", v);
+    }
+    printf("\n");
+  }
+#endif
+
+  /* Free memory allocations and return the result */
+  res = (int)m[szRow*(n2+1)-1];
+  n = n2;
+  if( f.isPrefix ){
+    for(i2=1; i2<=n2; i2++){
+      int b = m[szRow*i2-1];
+      if( b<=res ){ 
+        res = b;
+        n = i2 - 1;
+      }
+    }
+  }
+  if( pnMatch ){
+    int nExtra = 0;
+    for(k=0; k<n; k++){
+      if( (z2[k] & 0xc0)==0x80 ) nExtra++;
+    }
+    *pnMatch = n - nExtra;
+  }
+
+editDist3Abort:
+  for(i2=0; i2<n2; i2++) sqlite3_free(a2[i2].apIns);
+  sqlite3_free(m);
+  return res;
+}
+
+/*
+** Get an appropriate EditDist3Lang object.
+*/
+static const EditDist3Lang *editDist3FindLang(
+  EditDist3Config *pConfig,
+  int iLang
+){
+  int i;
+  for(i=0; i<pConfig->nLang; i++){
+    if( pConfig->a[i].iLang==iLang ) return &pConfig->a[i];
+  }
+  return &editDist3Lang;
+}
+
+/*
+** Function:    editdist3(A,B,iLang)
+**              editdist3(tablename)
+**
+** Return the cost of transforming string A into string B using edit
+** weights for iLang.
+**
+** The second form loads edit weights into memory from a table.
+*/
+static void editDist3SqlFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  EditDist3Config *pConfig = (EditDist3Config*)sqlite3_user_data(context);
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  int rc;
+  if( argc==1 ){
+    const char *zTable = (const char*)sqlite3_value_text(argv[0]);
+    rc = editDist3ConfigLoad(pConfig, db, zTable);
+    if( rc ) sqlite3_result_error_code(context, rc);
+  }else{
+    const char *zA = (const char*)sqlite3_value_text(argv[0]);
+    const char *zB = (const char*)sqlite3_value_text(argv[1]);
+    int nA = sqlite3_value_bytes(argv[0]);
+    int nB = sqlite3_value_bytes(argv[1]);
+    int iLang = argc==3 ? sqlite3_value_int(argv[2]) : 0;
+    const EditDist3Lang *pLang = editDist3FindLang(pConfig, iLang);
+    EditDist3FromString *pFrom;
+    int dist;
+
+    pFrom = editDist3FromStringNew(pLang, zA, nA);
+    if( pFrom==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
+    dist = editDist3Core(pFrom, zB, nB, pLang, 0);
+    editDist3FromStringDelete(pFrom);
+    if( dist==(-1) ){
+      sqlite3_result_error_nomem(context);
+    }else{
+      sqlite3_result_int(context, dist);
+    }
+  } 
+}
+
+/*
+** Register the editDist3 function with SQLite
+*/
+static int editDist3Install(sqlite3 *db){
+  int rc;
+  EditDist3Config *pConfig = sqlite3_malloc( sizeof(*pConfig) );
+  if( pConfig==0 ) return SQLITE_NOMEM;
+  memset(pConfig, 0, sizeof(*pConfig));
+  rc = sqlite3_create_function_v2(db, "editdist3",
+              2, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function_v2(db, "editdist3",
+                3, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function_v2(db, "editdist3",
+                1, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0,
+                editDist3ConfigDelete);
+  }else{
+    sqlite3_free(pConfig);
+  }
+  return rc;
+}
+/* End configurable cost unicode edit distance routines
+******************************************************************************
+******************************************************************************
+** Begin transliterate unicode-to-ascii implementation
+*/
+
+#if !SQLITE_AMALGAMATION
+/*
+** This lookup table is used to help decode the first byte of
+** a multi-byte UTF8 character.
+*/
+static const unsigned char sqlite3Utf8Trans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
+#endif
+
+/*
+** Return the value of the first UTF-8 character in the string.
+*/
+static int utf8Read(const unsigned char *z, int n, int *pSize){
+  int c, i;
+
+  /* All callers to this routine (in the current implementation)
+  ** always have n>0. */
+  if( NEVER(n==0) ){
+    c = i = 0;
+  }else{
+    c = z[0];
+    i = 1;
+    if( c>=0xc0 ){
+      c = sqlite3Utf8Trans1[c-0xc0];
+      while( i<n && (z[i] & 0xc0)==0x80 ){
+        c = (c<<6) + (0x3f & z[i++]);
+      }
+    }
+  }
+  *pSize = i;
+  return c;
+}
+
+/*
+** Return the number of characters in the utf-8 string in the nIn byte
+** buffer pointed to by zIn.
+*/
+static int utf8Charlen(const char *zIn, int nIn){
+  int i;
+  int nChar = 0;
+  for(i=0; i<nIn; nChar++){
+    int sz;
+    utf8Read((const unsigned char *)&zIn[i], nIn-i, &sz);
+    i += sz;
+  }
+  return nChar;
+}
+
+/*
+** Table of translations from unicode characters into ASCII.
+*/
+static const struct {
+ unsigned short int cFrom;
+ unsigned char cTo0, cTo1;
+} translit[] = {
+  { 0x00A0,  0x20, 0x00 },  /*   to   */
+  { 0x00B5,  0x75, 0x00 },  /* µ to u */
+  { 0x00C0,  0x41, 0x00 },  /* À to A */
+  { 0x00C1,  0x41, 0x00 },  /* Á to A */
+  { 0x00C2,  0x41, 0x00 },  /* Â to A */
+  { 0x00C3,  0x41, 0x00 },  /* Ã to A */
+  { 0x00C4,  0x41, 0x65 },  /* Ä to Ae */
+  { 0x00C5,  0x41, 0x61 },  /* Å to Aa */
+  { 0x00C6,  0x41, 0x45 },  /* Æ to AE */
+  { 0x00C7,  0x43, 0x00 },  /* Ç to C */
+  { 0x00C8,  0x45, 0x00 },  /* È to E */
+  { 0x00C9,  0x45, 0x00 },  /* É to E */
+  { 0x00CA,  0x45, 0x00 },  /* Ê to E */
+  { 0x00CB,  0x45, 0x00 },  /* Ë to E */
+  { 0x00CC,  0x49, 0x00 },  /* Ì to I */
+  { 0x00CD,  0x49, 0x00 },  /* Í to I */
+  { 0x00CE,  0x49, 0x00 },  /* Î to I */
+  { 0x00CF,  0x49, 0x00 },  /* Ï to I */
+  { 0x00D0,  0x44, 0x00 },  /* Ð to D */
+  { 0x00D1,  0x4E, 0x00 },  /* Ñ to N */
+  { 0x00D2,  0x4F, 0x00 },  /* Ò to O */
+  { 0x00D3,  0x4F, 0x00 },  /* Ó to O */
+  { 0x00D4,  0x4F, 0x00 },  /* Ô to O */
+  { 0x00D5,  0x4F, 0x00 },  /* Õ to O */
+  { 0x00D6,  0x4F, 0x65 },  /* Ö to Oe */
+  { 0x00D7,  0x78, 0x00 },  /* × to x */
+  { 0x00D8,  0x4F, 0x00 },  /* Ø to O */
+  { 0x00D9,  0x55, 0x00 },  /* Ù to U */
+  { 0x00DA,  0x55, 0x00 },  /* Ú to U */
+  { 0x00DB,  0x55, 0x00 },  /* Û to U */
+  { 0x00DC,  0x55, 0x65 },  /* Ü to Ue */
+  { 0x00DD,  0x59, 0x00 },  /* Ý to Y */
+  { 0x00DE,  0x54, 0x68 },  /* Þ to Th */
+  { 0x00DF,  0x73, 0x73 },  /* ß to ss */
+  { 0x00E0,  0x61, 0x00 },  /* à to a */
+  { 0x00E1,  0x61, 0x00 },  /* á to a */
+  { 0x00E2,  0x61, 0x00 },  /* â to a */
+  { 0x00E3,  0x61, 0x00 },  /* ã to a */
+  { 0x00E4,  0x61, 0x65 },  /* ä to ae */
+  { 0x00E5,  0x61, 0x61 },  /* å to aa */
+  { 0x00E6,  0x61, 0x65 },  /* æ to ae */
+  { 0x00E7,  0x63, 0x00 },  /* ç to c */
+  { 0x00E8,  0x65, 0x00 },  /* è to e */
+  { 0x00E9,  0x65, 0x00 },  /* é to e */
+  { 0x00EA,  0x65, 0x00 },  /* ê to e */
+  { 0x00EB,  0x65, 0x00 },  /* ë to e */
+  { 0x00EC,  0x69, 0x00 },  /* ì to i */
+  { 0x00ED,  0x69, 0x00 },  /* í to i */
+  { 0x00EE,  0x69, 0x00 },  /* î to i */
+  { 0x00EF,  0x69, 0x00 },  /* ï to i */
+  { 0x00F0,  0x64, 0x00 },  /* ð to d */
+  { 0x00F1,  0x6E, 0x00 },  /* ñ to n */
+  { 0x00F2,  0x6F, 0x00 },  /* ò to o */
+  { 0x00F3,  0x6F, 0x00 },  /* ó to o */
+  { 0x00F4,  0x6F, 0x00 },  /* ô to o */
+  { 0x00F5,  0x6F, 0x00 },  /* õ to o */
+  { 0x00F6,  0x6F, 0x65 },  /* ö to oe */
+  { 0x00F7,  0x3A, 0x00 },  /* ÷ to : */
+  { 0x00F8,  0x6F, 0x00 },  /* ø to o */
+  { 0x00F9,  0x75, 0x00 },  /* ù to u */
+  { 0x00FA,  0x75, 0x00 },  /* ú to u */
+  { 0x00FB,  0x75, 0x00 },  /* û to u */
+  { 0x00FC,  0x75, 0x65 },  /* ü to ue */
+  { 0x00FD,  0x79, 0x00 },  /* ý to y */
+  { 0x00FE,  0x74, 0x68 },  /* þ to th */
+  { 0x00FF,  0x79, 0x00 },  /* ÿ to y */
+  { 0x0100,  0x41, 0x00 },  /* Ā to A */
+  { 0x0101,  0x61, 0x00 },  /* ā to a */
+  { 0x0102,  0x41, 0x00 },  /* Ă to A */
+  { 0x0103,  0x61, 0x00 },  /* ă to a */
+  { 0x0104,  0x41, 0x00 },  /* Ą to A */
+  { 0x0105,  0x61, 0x00 },  /* ą to a */
+  { 0x0106,  0x43, 0x00 },  /* Ć to C */
+  { 0x0107,  0x63, 0x00 },  /* ć to c */
+  { 0x0108,  0x43, 0x68 },  /* Ĉ to Ch */
+  { 0x0109,  0x63, 0x68 },  /* ĉ to ch */
+  { 0x010A,  0x43, 0x00 },  /* Ċ to C */
+  { 0x010B,  0x63, 0x00 },  /* ċ to c */
+  { 0x010C,  0x43, 0x00 },  /* Č to C */
+  { 0x010D,  0x63, 0x00 },  /* č to c */
+  { 0x010E,  0x44, 0x00 },  /* Ď to D */
+  { 0x010F,  0x64, 0x00 },  /* ď to d */
+  { 0x0110,  0x44, 0x00 },  /* Đ to D */
+  { 0x0111,  0x64, 0x00 },  /* đ to d */
+  { 0x0112,  0x45, 0x00 },  /* Ē to E */
+  { 0x0113,  0x65, 0x00 },  /* ē to e */
+  { 0x0114,  0x45, 0x00 },  /* Ĕ to E */
+  { 0x0115,  0x65, 0x00 },  /* ĕ to e */
+  { 0x0116,  0x45, 0x00 },  /* Ė to E */
+  { 0x0117,  0x65, 0x00 },  /* ė to e */
+  { 0x0118,  0x45, 0x00 },  /* Ę to E */
+  { 0x0119,  0x65, 0x00 },  /* ę to e */
+  { 0x011A,  0x45, 0x00 },  /* Ě to E */
+  { 0x011B,  0x65, 0x00 },  /* ě to e */
+  { 0x011C,  0x47, 0x68 },  /* Ĝ to Gh */
+  { 0x011D,  0x67, 0x68 },  /* ĝ to gh */
+  { 0x011E,  0x47, 0x00 },  /* Ğ to G */
+  { 0x011F,  0x67, 0x00 },  /* ğ to g */
+  { 0x0120,  0x47, 0x00 },  /* Ġ to G */
+  { 0x0121,  0x67, 0x00 },  /* ġ to g */
+  { 0x0122,  0x47, 0x00 },  /* Ģ to G */
+  { 0x0123,  0x67, 0x00 },  /* ģ to g */
+  { 0x0124,  0x48, 0x68 },  /* Ĥ to Hh */
+  { 0x0125,  0x68, 0x68 },  /* ĥ to hh */
+  { 0x0126,  0x48, 0x00 },  /* Ħ to H */
+  { 0x0127,  0x68, 0x00 },  /* ħ to h */
+  { 0x0128,  0x49, 0x00 },  /* Ĩ to I */
+  { 0x0129,  0x69, 0x00 },  /* ĩ to i */
+  { 0x012A,  0x49, 0x00 },  /* Ī to I */
+  { 0x012B,  0x69, 0x00 },  /* ī to i */
+  { 0x012C,  0x49, 0x00 },  /* Ĭ to I */
+  { 0x012D,  0x69, 0x00 },  /* ĭ to i */
+  { 0x012E,  0x49, 0x00 },  /* Į to I */
+  { 0x012F,  0x69, 0x00 },  /* į to i */
+  { 0x0130,  0x49, 0x00 },  /* İ to I */
+  { 0x0131,  0x69, 0x00 },  /* ı to i */
+  { 0x0132,  0x49, 0x4A },  /* IJ to IJ */
+  { 0x0133,  0x69, 0x6A },  /* ij to ij */
+  { 0x0134,  0x4A, 0x68 },  /* Ĵ to Jh */
+  { 0x0135,  0x6A, 0x68 },  /* ĵ to jh */
+  { 0x0136,  0x4B, 0x00 },  /* Ķ to K */
+  { 0x0137,  0x6B, 0x00 },  /* ķ to k */
+  { 0x0138,  0x6B, 0x00 },  /* ĸ to k */
+  { 0x0139,  0x4C, 0x00 },  /* Ĺ to L */
+  { 0x013A,  0x6C, 0x00 },  /* ĺ to l */
+  { 0x013B,  0x4C, 0x00 },  /* Ļ to L */
+  { 0x013C,  0x6C, 0x00 },  /* ļ to l */
+  { 0x013D,  0x4C, 0x00 },  /* Ľ to L */
+  { 0x013E,  0x6C, 0x00 },  /* ľ to l */
+  { 0x013F,  0x4C, 0x2E },  /* Ŀ to L. */
+  { 0x0140,  0x6C, 0x2E },  /* ŀ to l. */
+  { 0x0141,  0x4C, 0x00 },  /* Ł to L */
+  { 0x0142,  0x6C, 0x00 },  /* ł to l */
+  { 0x0143,  0x4E, 0x00 },  /* Ń to N */
+  { 0x0144,  0x6E, 0x00 },  /* ń to n */
+  { 0x0145,  0x4E, 0x00 },  /* Ņ to N */
+  { 0x0146,  0x6E, 0x00 },  /* ņ to n */
+  { 0x0147,  0x4E, 0x00 },  /* Ň to N */
+  { 0x0148,  0x6E, 0x00 },  /* ň to n */
+  { 0x0149,  0x27, 0x6E },  /* ʼn to 'n */
+  { 0x014A,  0x4E, 0x47 },  /* Ŋ to NG */
+  { 0x014B,  0x6E, 0x67 },  /* ŋ to ng */
+  { 0x014C,  0x4F, 0x00 },  /* Ō to O */
+  { 0x014D,  0x6F, 0x00 },  /* ō to o */
+  { 0x014E,  0x4F, 0x00 },  /* Ŏ to O */
+  { 0x014F,  0x6F, 0x00 },  /* ŏ to o */
+  { 0x0150,  0x4F, 0x00 },  /* Ő to O */
+  { 0x0151,  0x6F, 0x00 },  /* ő to o */
+  { 0x0152,  0x4F, 0x45 },  /* Πto OE */
+  { 0x0153,  0x6F, 0x65 },  /* œ to oe */
+  { 0x0154,  0x52, 0x00 },  /* Ŕ to R */
+  { 0x0155,  0x72, 0x00 },  /* ŕ to r */
+  { 0x0156,  0x52, 0x00 },  /* Ŗ to R */
+  { 0x0157,  0x72, 0x00 },  /* ŗ to r */
+  { 0x0158,  0x52, 0x00 },  /* Ř to R */
+  { 0x0159,  0x72, 0x00 },  /* ř to r */
+  { 0x015A,  0x53, 0x00 },  /* Ś to S */
+  { 0x015B,  0x73, 0x00 },  /* ś to s */
+  { 0x015C,  0x53, 0x68 },  /* Ŝ to Sh */
+  { 0x015D,  0x73, 0x68 },  /* ŝ to sh */
+  { 0x015E,  0x53, 0x00 },  /* Ş to S */
+  { 0x015F,  0x73, 0x00 },  /* ş to s */
+  { 0x0160,  0x53, 0x00 },  /* Š to S */
+  { 0x0161,  0x73, 0x00 },  /* š to s */
+  { 0x0162,  0x54, 0x00 },  /* Ţ to T */
+  { 0x0163,  0x74, 0x00 },  /* ţ to t */
+  { 0x0164,  0x54, 0x00 },  /* Ť to T */
+  { 0x0165,  0x74, 0x00 },  /* ť to t */
+  { 0x0166,  0x54, 0x00 },  /* Ŧ to T */
+  { 0x0167,  0x74, 0x00 },  /* ŧ to t */
+  { 0x0168,  0x55, 0x00 },  /* Ũ to U */
+  { 0x0169,  0x75, 0x00 },  /* ũ to u */
+  { 0x016A,  0x55, 0x00 },  /* Ū to U */
+  { 0x016B,  0x75, 0x00 },  /* ū to u */
+  { 0x016C,  0x55, 0x00 },  /* Ŭ to U */
+  { 0x016D,  0x75, 0x00 },  /* ŭ to u */
+  { 0x016E,  0x55, 0x00 },  /* Ů to U */
+  { 0x016F,  0x75, 0x00 },  /* ů to u */
+  { 0x0170,  0x55, 0x00 },  /* Ű to U */
+  { 0x0171,  0x75, 0x00 },  /* ű to u */
+  { 0x0172,  0x55, 0x00 },  /* Ų to U */
+  { 0x0173,  0x75, 0x00 },  /* ų to u */
+  { 0x0174,  0x57, 0x00 },  /* Ŵ to W */
+  { 0x0175,  0x77, 0x00 },  /* ŵ to w */
+  { 0x0176,  0x59, 0x00 },  /* Ŷ to Y */
+  { 0x0177,  0x79, 0x00 },  /* ŷ to y */
+  { 0x0178,  0x59, 0x00 },  /* Ÿ to Y */
+  { 0x0179,  0x5A, 0x00 },  /* Ź to Z */
+  { 0x017A,  0x7A, 0x00 },  /* ź to z */
+  { 0x017B,  0x5A, 0x00 },  /* Ż to Z */
+  { 0x017C,  0x7A, 0x00 },  /* ż to z */
+  { 0x017D,  0x5A, 0x00 },  /* Ž to Z */
+  { 0x017E,  0x7A, 0x00 },  /* ž to z */
+  { 0x017F,  0x73, 0x00 },  /* ſ to s */
+  { 0x0192,  0x66, 0x00 },  /* ƒ to f */
+  { 0x0218,  0x53, 0x00 },  /* Ș to S */
+  { 0x0219,  0x73, 0x00 },  /* ș to s */
+  { 0x021A,  0x54, 0x00 },  /* Ț to T */
+  { 0x021B,  0x74, 0x00 },  /* ț to t */
+  { 0x0386,  0x41, 0x00 },  /* Ά to A */
+  { 0x0388,  0x45, 0x00 },  /* Έ to E */
+  { 0x0389,  0x49, 0x00 },  /* Ή to I */
+  { 0x038A,  0x49, 0x00 },  /* Ί to I */
+  { 0x038C,  0x4f, 0x00 },  /* Ό to O */
+  { 0x038E,  0x59, 0x00 },  /* Ύ to Y */
+  { 0x038F,  0x4f, 0x00 },  /* Ώ to O */
+  { 0x0390,  0x69, 0x00 },  /* ΐ to i */
+  { 0x0391,  0x41, 0x00 },  /* Α to A */
+  { 0x0392,  0x42, 0x00 },  /* Β to B */
+  { 0x0393,  0x47, 0x00 },  /* Γ to G */
+  { 0x0394,  0x44, 0x00 },  /* Δ to D */
+  { 0x0395,  0x45, 0x00 },  /* Ε to E */
+  { 0x0396,  0x5a, 0x00 },  /* Ζ to Z */
+  { 0x0397,  0x49, 0x00 },  /* Η to I */
+  { 0x0398,  0x54, 0x68 },  /* Θ to Th */
+  { 0x0399,  0x49, 0x00 },  /* Ι to I */
+  { 0x039A,  0x4b, 0x00 },  /* Κ to K */
+  { 0x039B,  0x4c, 0x00 },  /* Λ to L */
+  { 0x039C,  0x4d, 0x00 },  /* Μ to M */
+  { 0x039D,  0x4e, 0x00 },  /* Ν to N */
+  { 0x039E,  0x58, 0x00 },  /* Ξ to X */
+  { 0x039F,  0x4f, 0x00 },  /* Ο to O */
+  { 0x03A0,  0x50, 0x00 },  /* Π to P */
+  { 0x03A1,  0x52, 0x00 },  /* Ρ to R */
+  { 0x03A3,  0x53, 0x00 },  /* Σ to S */
+  { 0x03A4,  0x54, 0x00 },  /* Τ to T */
+  { 0x03A5,  0x59, 0x00 },  /* Υ to Y */
+  { 0x03A6,  0x46, 0x00 },  /* Φ to F */
+  { 0x03A7,  0x43, 0x68 },  /* Χ to Ch */
+  { 0x03A8,  0x50, 0x73 },  /* Ψ to Ps */
+  { 0x03A9,  0x4f, 0x00 },  /* Ω to O */
+  { 0x03AA,  0x49, 0x00 },  /* Ϊ to I */
+  { 0x03AB,  0x59, 0x00 },  /* Ϋ to Y */
+  { 0x03AC,  0x61, 0x00 },  /* ά to a */
+  { 0x03AD,  0x65, 0x00 },  /* έ to e */
+  { 0x03AE,  0x69, 0x00 },  /* ή to i */
+  { 0x03AF,  0x69, 0x00 },  /* ί to i */
+  { 0x03B1,  0x61, 0x00 },  /* α to a */
+  { 0x03B2,  0x62, 0x00 },  /* β to b */
+  { 0x03B3,  0x67, 0x00 },  /* γ to g */
+  { 0x03B4,  0x64, 0x00 },  /* δ to d */
+  { 0x03B5,  0x65, 0x00 },  /* ε to e */
+  { 0x03B6,  0x7a, 0x00 },  /* ζ to z */
+  { 0x03B7,  0x69, 0x00 },  /* η to i */
+  { 0x03B8,  0x74, 0x68 },  /* θ to th */
+  { 0x03B9,  0x69, 0x00 },  /* ι to i */
+  { 0x03BA,  0x6b, 0x00 },  /* κ to k */
+  { 0x03BB,  0x6c, 0x00 },  /* λ to l */
+  { 0x03BC,  0x6d, 0x00 },  /* μ to m */
+  { 0x03BD,  0x6e, 0x00 },  /* ν to n */
+  { 0x03BE,  0x78, 0x00 },  /* ξ to x */
+  { 0x03BF,  0x6f, 0x00 },  /* ο to o */
+  { 0x03C0,  0x70, 0x00 },  /* π to p */
+  { 0x03C1,  0x72, 0x00 },  /* ρ to r */
+  { 0x03C3,  0x73, 0x00 },  /* σ to s */
+  { 0x03C4,  0x74, 0x00 },  /* τ to t */
+  { 0x03C5,  0x79, 0x00 },  /* υ to y */
+  { 0x03C6,  0x66, 0x00 },  /* φ to f */
+  { 0x03C7,  0x63, 0x68 },  /* χ to ch */
+  { 0x03C8,  0x70, 0x73 },  /* ψ to ps */
+  { 0x03C9,  0x6f, 0x00 },  /* ω to o */
+  { 0x03CA,  0x69, 0x00 },  /* ϊ to i */
+  { 0x03CB,  0x79, 0x00 },  /* ϋ to y */
+  { 0x03CC,  0x6f, 0x00 },  /* ό to o */
+  { 0x03CD,  0x79, 0x00 },  /* ύ to y */
+  { 0x03CE,  0x69, 0x00 },  /* ώ to i */
+  { 0x0400,  0x45, 0x00 },  /* Ѐ to E */
+  { 0x0401,  0x45, 0x00 },  /* Ё to E */
+  { 0x0402,  0x44, 0x00 },  /* Ђ to D */
+  { 0x0403,  0x47, 0x00 },  /* Ѓ to G */
+  { 0x0404,  0x45, 0x00 },  /* Є to E */
+  { 0x0405,  0x5a, 0x00 },  /* Ѕ to Z */
+  { 0x0406,  0x49, 0x00 },  /* І to I */
+  { 0x0407,  0x49, 0x00 },  /* Ї to I */
+  { 0x0408,  0x4a, 0x00 },  /* Ј to J */
+  { 0x0409,  0x49, 0x00 },  /* Љ to I */
+  { 0x040A,  0x4e, 0x00 },  /* Њ to N */
+  { 0x040B,  0x44, 0x00 },  /* Ћ to D */
+  { 0x040C,  0x4b, 0x00 },  /* Ќ to K */
+  { 0x040D,  0x49, 0x00 },  /* Ѝ to I */
+  { 0x040E,  0x55, 0x00 },  /* Ў to U */
+  { 0x040F,  0x44, 0x00 },  /* Џ to D */
+  { 0x0410,  0x41, 0x00 },  /* А to A */
+  { 0x0411,  0x42, 0x00 },  /* Б to B */
+  { 0x0412,  0x56, 0x00 },  /* В to V */
+  { 0x0413,  0x47, 0x00 },  /* Г to G */
+  { 0x0414,  0x44, 0x00 },  /* Д to D */
+  { 0x0415,  0x45, 0x00 },  /* Е to E */
+  { 0x0416,  0x5a, 0x68 },  /* Ж to Zh */
+  { 0x0417,  0x5a, 0x00 },  /* З to Z */
+  { 0x0418,  0x49, 0x00 },  /* И to I */
+  { 0x0419,  0x49, 0x00 },  /* Й to I */
+  { 0x041A,  0x4b, 0x00 },  /* К to K */
+  { 0x041B,  0x4c, 0x00 },  /* Л to L */
+  { 0x041C,  0x4d, 0x00 },  /* М to M */
+  { 0x041D,  0x4e, 0x00 },  /* Н to N */
+  { 0x041E,  0x4f, 0x00 },  /* О to O */
+  { 0x041F,  0x50, 0x00 },  /* П to P */
+  { 0x0420,  0x52, 0x00 },  /* Р to R */
+  { 0x0421,  0x53, 0x00 },  /* С to S */
+  { 0x0422,  0x54, 0x00 },  /* Т to T */
+  { 0x0423,  0x55, 0x00 },  /* У to U */
+  { 0x0424,  0x46, 0x00 },  /* Ф to F */
+  { 0x0425,  0x4b, 0x68 },  /* Х to Kh */
+  { 0x0426,  0x54, 0x63 },  /* Ц to Tc */
+  { 0x0427,  0x43, 0x68 },  /* Ч to Ch */
+  { 0x0428,  0x53, 0x68 },  /* Ш to Sh */
+  { 0x0429,  0x53, 0x68 },  /* Щ to Shch */
+  { 0x042A,  0x61, 0x00 },  /*  to A */
+  { 0x042B,  0x59, 0x00 },  /* Ы to Y */
+  { 0x042C,  0x59, 0x00 },  /*  to Y */
+  { 0x042D,  0x45, 0x00 },  /* Э to E */
+  { 0x042E,  0x49, 0x75 },  /* Ю to Iu */
+  { 0x042F,  0x49, 0x61 },  /* Я to Ia */
+  { 0x0430,  0x61, 0x00 },  /* а to a */
+  { 0x0431,  0x62, 0x00 },  /* б to b */
+  { 0x0432,  0x76, 0x00 },  /* в to v */
+  { 0x0433,  0x67, 0x00 },  /* г to g */
+  { 0x0434,  0x64, 0x00 },  /* д to d */
+  { 0x0435,  0x65, 0x00 },  /* е to e */
+  { 0x0436,  0x7a, 0x68 },  /* ж to zh */
+  { 0x0437,  0x7a, 0x00 },  /* з to z */
+  { 0x0438,  0x69, 0x00 },  /* и to i */
+  { 0x0439,  0x69, 0x00 },  /* й to i */
+  { 0x043A,  0x6b, 0x00 },  /* к to k */
+  { 0x043B,  0x6c, 0x00 },  /* л to l */
+  { 0x043C,  0x6d, 0x00 },  /* м to m */
+  { 0x043D,  0x6e, 0x00 },  /* н to n */
+  { 0x043E,  0x6f, 0x00 },  /* о to o */
+  { 0x043F,  0x70, 0x00 },  /* п to p */
+  { 0x0440,  0x72, 0x00 },  /* р to r */
+  { 0x0441,  0x73, 0x00 },  /* с to s */
+  { 0x0442,  0x74, 0x00 },  /* т to t */
+  { 0x0443,  0x75, 0x00 },  /* у to u */
+  { 0x0444,  0x66, 0x00 },  /* ф to f */
+  { 0x0445,  0x6b, 0x68 },  /* х to kh */
+  { 0x0446,  0x74, 0x63 },  /* ц to tc */
+  { 0x0447,  0x63, 0x68 },  /* ч to ch */
+  { 0x0448,  0x73, 0x68 },  /* ш to sh */
+  { 0x0449,  0x73, 0x68 },  /* щ to shch */
+  { 0x044A,  0x61, 0x00 },  /*  to a */
+  { 0x044B,  0x79, 0x00 },  /* ы to y */
+  { 0x044C,  0x79, 0x00 },  /*  to y */
+  { 0x044D,  0x65, 0x00 },  /* э to e */
+  { 0x044E,  0x69, 0x75 },  /* ю to iu */
+  { 0x044F,  0x69, 0x61 },  /* я to ia */
+  { 0x0450,  0x65, 0x00 },  /* ѐ to e */
+  { 0x0451,  0x65, 0x00 },  /* ё to e */
+  { 0x0452,  0x64, 0x00 },  /* ђ to d */
+  { 0x0453,  0x67, 0x00 },  /* ѓ to g */
+  { 0x0454,  0x65, 0x00 },  /* є to e */
+  { 0x0455,  0x7a, 0x00 },  /* ѕ to z */
+  { 0x0456,  0x69, 0x00 },  /* і to i */
+  { 0x0457,  0x69, 0x00 },  /* ї to i */
+  { 0x0458,  0x6a, 0x00 },  /* ј to j */
+  { 0x0459,  0x69, 0x00 },  /* љ to i */
+  { 0x045A,  0x6e, 0x00 },  /* њ to n */
+  { 0x045B,  0x64, 0x00 },  /* ћ to d */
+  { 0x045C,  0x6b, 0x00 },  /* ќ to k */
+  { 0x045D,  0x69, 0x00 },  /* ѝ to i */
+  { 0x045E,  0x75, 0x00 },  /* ў to u */
+  { 0x045F,  0x64, 0x00 },  /* џ to d */
+  { 0x1E02,  0x42, 0x00 },  /* Ḃ to B */
+  { 0x1E03,  0x62, 0x00 },  /* ḃ to b */
+  { 0x1E0A,  0x44, 0x00 },  /* Ḋ to D */
+  { 0x1E0B,  0x64, 0x00 },  /* ḋ to d */
+  { 0x1E1E,  0x46, 0x00 },  /* Ḟ to F */
+  { 0x1E1F,  0x66, 0x00 },  /* ḟ to f */
+  { 0x1E40,  0x4D, 0x00 },  /* Ṁ to M */
+  { 0x1E41,  0x6D, 0x00 },  /* ṁ to m */
+  { 0x1E56,  0x50, 0x00 },  /* Ṗ to P */
+  { 0x1E57,  0x70, 0x00 },  /* ṗ to p */
+  { 0x1E60,  0x53, 0x00 },  /* Ṡ to S */
+  { 0x1E61,  0x73, 0x00 },  /* ṡ to s */
+  { 0x1E6A,  0x54, 0x00 },  /* Ṫ to T */
+  { 0x1E6B,  0x74, 0x00 },  /* ṫ to t */
+  { 0x1E80,  0x57, 0x00 },  /* Ẁ to W */
+  { 0x1E81,  0x77, 0x00 },  /* ẁ to w */
+  { 0x1E82,  0x57, 0x00 },  /* Ẃ to W */
+  { 0x1E83,  0x77, 0x00 },  /* ẃ to w */
+  { 0x1E84,  0x57, 0x00 },  /* Ẅ to W */
+  { 0x1E85,  0x77, 0x00 },  /* ẅ to w */
+  { 0x1EF2,  0x59, 0x00 },  /* Ỳ to Y */
+  { 0x1EF3,  0x79, 0x00 },  /* ỳ to y */
+  { 0xFB00,  0x66, 0x66 },  /* ff to ff */
+  { 0xFB01,  0x66, 0x69 },  /* fi to fi */
+  { 0xFB02,  0x66, 0x6C },  /* fl to fl */
+  { 0xFB05,  0x73, 0x74 },  /* ſt to st */
+  { 0xFB06,  0x73, 0x74 },  /* st to st */
+};
+
+/*
+** Convert the input string from UTF-8 into pure ASCII by converting
+** all non-ASCII characters to some combination of characters in the
+** ASCII subset.
+**
+** The returned string might contain more characters than the input.
+**
+** Space to hold the returned string comes from sqlite3_malloc() and
+** should be freed by the caller.
+*/
+static unsigned char *transliterate(const unsigned char *zIn, int nIn){
+  unsigned char *zOut = sqlite3_malloc( nIn*4 + 1 );
+  int c, sz, nOut;
+  if( zOut==0 ) return 0;
+  nOut = 0;
+  while( nIn>0 ){
+    c = utf8Read(zIn, nIn, &sz);
+    zIn += sz;
+    nIn -= sz;
+    if( c<=127 ){
+      zOut[nOut++] = c;
+    }else{
+      int xTop, xBtm, x;
+      xTop = sizeof(translit)/sizeof(translit[0]) - 1;
+      xBtm = 0;
+      while( xTop>=xBtm ){
+        x = (xTop + xBtm)/2;
+        if( translit[x].cFrom==c ){
+          zOut[nOut++] = translit[x].cTo0;
+          if( translit[x].cTo1 ){
+            zOut[nOut++] = translit[x].cTo1;
+            /* Add an extra "ch" after the "sh" for Щ and щ */
+            if( c==0x0429 || c== 0x0449 ){
+              zOut[nOut++] = 'c';
+              zOut[nOut++] = 'h';
+            }
+          }
+          c = 0;
+          break;
+        }else if( translit[x].cFrom>c ){
+          xTop = x-1;
+        }else{
+          xBtm = x+1;
+        }
+      }
+      if( c ) zOut[nOut++] = '?';
+    }
+  }
+  zOut[nOut] = 0;
+  return zOut;
+}
+
+/*
+** Return the number of characters in the shortest prefix of the input
+** string that transliterates to an ASCII string nTrans bytes or longer.
+** Or, if the transliteration of the input string is less than nTrans
+** bytes in size, return the number of characters in the input string.
+*/
+static int translen_to_charlen(const char *zIn, int nIn, int nTrans){
+  int i, c, sz, nOut;
+  int nChar;
+
+  i = nOut = 0;
+  for(nChar=0; i<nIn && nOut<nTrans; nChar++){
+    c = utf8Read((const unsigned char *)&zIn[i], nIn-i, &sz);
+    i += sz;
+
+    nOut++;
+    if( c>=128 ){
+      int xTop, xBtm, x;
+      xTop = sizeof(translit)/sizeof(translit[0]) - 1;
+      xBtm = 0;
+      while( xTop>=xBtm ){
+        x = (xTop + xBtm)/2;
+        if( translit[x].cFrom==c ){
+          if( translit[x].cTo1 ) nOut++;
+          if( c==0x0429 || c== 0x0449 ) nOut += 2;
+          break;
+        }else if( translit[x].cFrom>c ){
+          xTop = x-1;
+        }else{
+          xBtm = x+1;
+        }
+      }
+    }
+  }
+
+  return nChar;
+}
+
+
+/*
+**    spellfix1_translit(X)
+**
+** Convert a string that contains non-ASCII Roman characters into 
+** pure ASCII.
+*/
+static void transliterateSqlFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zIn = sqlite3_value_text(argv[0]);
+  int nIn = sqlite3_value_bytes(argv[0]);
+  unsigned char *zOut = transliterate(zIn, nIn);
+  if( zOut==0 ){
+    sqlite3_result_error_nomem(context);
+  }else{
+    sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free);
+  }
+}
+
+/*
+**    spellfix1_scriptcode(X)
+**
+** Try to determine the dominant script used by the word X and return
+** its ISO 15924 numeric code.
+**
+** The current implementation only understands the following scripts:
+**
+**    215  (Latin)
+**    220  (Cyrillic)
+**    200  (Greek)
+**
+** This routine will return 998 if the input X contains characters from
+** two or more of the above scripts or 999 if X contains no characters
+** from any of the above scripts.
+*/
+static void scriptCodeSqlFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zIn = sqlite3_value_text(argv[0]);
+  int nIn = sqlite3_value_bytes(argv[0]);
+  int c, sz;
+  int scriptMask = 0;
+  int res;
+# define SCRIPT_LATIN       0x0001
+# define SCRIPT_CYRILLIC    0x0002
+# define SCRIPT_GREEK       0x0004
+
+  while( nIn>0 ){
+    c = utf8Read(zIn, nIn, &sz);
+    zIn += sz;
+    nIn -= sz;
+    if( c<0x02af ){
+      scriptMask |= SCRIPT_LATIN;
+    }else if( c>=0x0400 && c<=0x04ff ){
+      scriptMask |= SCRIPT_CYRILLIC;
+    }else if( c>=0x0386 && c<=0x03ce ){
+      scriptMask |= SCRIPT_GREEK;
+    }
+  }
+  switch( scriptMask ){
+    case 0:                res = 999; break;
+    case SCRIPT_LATIN:     res = 215; break;
+    case SCRIPT_CYRILLIC:  res = 220; break;
+    case SCRIPT_GREEK:     res = 200; break;
+    default:               res = 998; break;
+  }
+  sqlite3_result_int(context, res);
+}
+
+/* End transliterate
+******************************************************************************
+******************************************************************************
+** Begin spellfix1 virtual table.
+*/
+
+/* Maximum length of a phonehash used for querying the shadow table */
+#define SPELLFIX_MX_HASH  8
+
+/* Maximum number of hash strings to examine per query */
+#define SPELLFIX_MX_RUN   1
+
+typedef struct spellfix1_vtab spellfix1_vtab;
+typedef struct spellfix1_cursor spellfix1_cursor;
+
+/* Fuzzy-search virtual table object */
+struct spellfix1_vtab {
+  sqlite3_vtab base;         /* Base class - must be first */
+  sqlite3 *db;               /* Database connection */
+  char *zDbName;             /* Name of database holding this table */
+  char *zTableName;          /* Name of the virtual table */
+  char *zCostTable;          /* Table holding edit-distance cost numbers */
+  EditDist3Config *pConfig3; /* Parsed edit distance costs */
+};
+
+/* Fuzzy-search cursor object */
+struct spellfix1_cursor {
+  sqlite3_vtab_cursor base;    /* Base class - must be first */
+  spellfix1_vtab *pVTab;       /* The table to which this cursor belongs */
+  char *zPattern;              /* rhs of MATCH clause */
+  int nRow;                    /* Number of rows of content */
+  int nAlloc;                  /* Number of allocated rows */
+  int iRow;                    /* Current row of content */
+  int iLang;                   /* Value of the langid= constraint */
+  int iTop;                    /* Value of the top= constraint */
+  int iScope;                  /* Value of the scope= constraint */
+  int nSearch;                 /* Number of vocabulary items checked */
+  sqlite3_stmt *pFullScan;     /* Shadow query for a full table scan */
+  struct spellfix1_row {       /* For each row of content */
+    sqlite3_int64 iRowid;         /* Rowid for this row */
+    char *zWord;                  /* Text for this row */
+    int iRank;                    /* Rank for this row */
+    int iDistance;                /* Distance from pattern for this row */
+    int iScore;                   /* Score for sorting */
+    int iMatchlen;                /* Value of matchlen column (or -1) */
+    char zHash[SPELLFIX_MX_HASH]; /* the phonehash used for this match */
+  } *a; 
+};
+
+/*
+** Construct one or more SQL statements from the format string given
+** and then evaluate those statements. The success code is written
+** into *pRc.
+**
+** If *pRc is initially non-zero then this routine is a no-op.
+*/
+static void spellfix1DbExec(
+  int *pRc,              /* Success code */
+  sqlite3 *db,           /* Database in which to run SQL */
+  const char *zFormat,   /* Format string for SQL */
+  ...                    /* Arguments to the format string */
+){
+  va_list ap;
+  char *zSql;
+  if( *pRc ) return;
+  va_start(ap, zFormat);
+  zSql = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  if( zSql==0 ){
+    *pRc = SQLITE_NOMEM;
+  }else{
+    *pRc = sqlite3_exec(db, zSql, 0, 0, 0);
+    sqlite3_free(zSql);
+  }
+}
+
+/*
+** xDisconnect/xDestroy method for the fuzzy-search module.
+*/
+static int spellfix1Uninit(int isDestroy, sqlite3_vtab *pVTab){
+  spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+  int rc = SQLITE_OK;
+  if( isDestroy ){
+    sqlite3 *db = p->db;
+    spellfix1DbExec(&rc, db, "DROP TABLE IF EXISTS \"%w\".\"%w_vocab\"",
+                  p->zDbName, p->zTableName);
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3_free(p->zTableName);
+    editDist3ConfigDelete(p->pConfig3);
+    sqlite3_free(p->zCostTable);
+    sqlite3_free(p);
+  }
+  return rc;
+}
+static int spellfix1Disconnect(sqlite3_vtab *pVTab){
+  return spellfix1Uninit(0, pVTab);
+}
+static int spellfix1Destroy(sqlite3_vtab *pVTab){
+  return spellfix1Uninit(1, pVTab);
+}
+
+/*
+** Make a copy of a string.  Remove leading and trailing whitespace
+** and dequote it.
+*/
+static char *spellfix1Dequote(const char *zIn){
+  char *zOut;
+  int i, j;
+  char c;
+  while( isspace(zIn[0]) ) zIn++;
+  zOut = sqlite3_mprintf("%s", zIn);
+  if( zOut==0 ) return 0;
+  i = (int)strlen(zOut);
+#if 0  /* The parser will never leave spaces at the end */
+  while( i>0 && isspace(zOut[i-1]) ){ i--; }
+#endif
+  zOut[i] = 0;
+  c = zOut[0];
+  if( c=='\'' || c=='"' ){
+    for(i=1, j=0; ALWAYS(zOut[i]); i++){
+      zOut[j++] = zOut[i];
+      if( zOut[i]==c ){
+        if( zOut[i+1]==c ){
+          i++;
+        }else{
+          zOut[j-1] = 0;
+          break;
+        }
+      }
+    }
+  }
+  return zOut;
+}
+
+
+/*
+** xConnect/xCreate method for the spellfix1 module. Arguments are:
+**
+**   argv[0]   -> module name  ("spellfix1")
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**   argv[3].. -> optional arguments (i.e. "edit_cost_table" parameter)
+*/
+static int spellfix1Init(
+  int isCreate,
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
+  spellfix1_vtab *pNew = 0;
+  const char *zModule = argv[0];
+  const char *zDbName = argv[1];
+  const char *zTableName = argv[2];
+  int nDbName;
+  int rc = SQLITE_OK;
+  int i;
+
+  nDbName = (int)strlen(zDbName);
+  pNew = sqlite3_malloc( sizeof(*pNew) + nDbName + 1);
+  if( pNew==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    memset(pNew, 0, sizeof(*pNew));
+    pNew->zDbName = (char*)&pNew[1];
+    memcpy(pNew->zDbName, zDbName, nDbName+1);
+    pNew->zTableName = sqlite3_mprintf("%s", zTableName);
+    pNew->db = db;
+    if( pNew->zTableName==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_declare_vtab(db, 
+           "CREATE TABLE x(word,rank,distance,langid, "
+           "score, matchlen, phonehash HIDDEN, "
+           "top HIDDEN, scope HIDDEN, srchcnt HIDDEN, "
+           "soundslike HIDDEN, command HIDDEN)"
+      );
+#define SPELLFIX_COL_WORD            0
+#define SPELLFIX_COL_RANK            1
+#define SPELLFIX_COL_DISTANCE        2
+#define SPELLFIX_COL_LANGID          3
+#define SPELLFIX_COL_SCORE           4
+#define SPELLFIX_COL_MATCHLEN        5
+#define SPELLFIX_COL_PHONEHASH       6
+#define SPELLFIX_COL_TOP             7
+#define SPELLFIX_COL_SCOPE           8
+#define SPELLFIX_COL_SRCHCNT         9
+#define SPELLFIX_COL_SOUNDSLIKE     10
+#define SPELLFIX_COL_COMMAND        11
+    }
+    if( rc==SQLITE_OK && isCreate ){
+      sqlite3_uint64 r;
+      spellfix1DbExec(&rc, db,
+         "CREATE TABLE IF NOT EXISTS \"%w\".\"%w_vocab\"(\n"
+         "  id INTEGER PRIMARY KEY,\n"
+         "  rank INT,\n"
+         "  langid INT,\n"
+         "  word TEXT,\n"
+         "  k1 TEXT,\n"
+         "  k2 TEXT\n"
+         ");\n",
+         zDbName, zTableName
+      );
+      sqlite3_randomness(sizeof(r), &r);
+      spellfix1DbExec(&rc, db,
+         "CREATE INDEX IF NOT EXISTS \"%w\".\"%w_index_%llx\" "
+            "ON \"%w_vocab\"(langid,k2);",
+         zDbName, zModule, r, zTableName
+      );
+    }
+    for(i=3; rc==SQLITE_OK && i<argc; i++){
+      if( strncmp(argv[i],"edit_cost_table=",16)==0 && pNew->zCostTable==0 ){
+        pNew->zCostTable = spellfix1Dequote(&argv[i][16]);
+        if( pNew->zCostTable==0 ) rc = SQLITE_NOMEM;
+        continue;
+      }
+      *pzErr = sqlite3_mprintf("bad argument to spellfix1(): \"%s\"", argv[i]);
+      rc = SQLITE_ERROR; 
+    }
+  }
+
+  if( rc && pNew ){
+    *ppVTab = 0;
+    spellfix1Uninit(0, &pNew->base);
+  }else{
+    *ppVTab = (sqlite3_vtab *)pNew;
+  }
+  return rc;
+}
+
+/*
+** The xConnect and xCreate methods
+*/
+static int spellfix1Connect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
+  return spellfix1Init(0, db, pAux, argc, argv, ppVTab, pzErr);
+}
+static int spellfix1Create(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
+  return spellfix1Init(1, db, pAux, argc, argv, ppVTab, pzErr);
+}
+
+/*
+** Clear all of the content from a cursor.
+*/
+static void spellfix1ResetCursor(spellfix1_cursor *pCur){
+  int i;
+  for(i=0; i<pCur->nRow; i++){
+    sqlite3_free(pCur->a[i].zWord);
+  }
+  pCur->nRow = 0;
+  pCur->iRow = 0;
+  pCur->nSearch = 0;
+  if( pCur->pFullScan ){
+    sqlite3_finalize(pCur->pFullScan);
+    pCur->pFullScan = 0;
+  }
+}
+
+/*
+** Resize the cursor to hold up to N rows of content
+*/
+static void spellfix1ResizeCursor(spellfix1_cursor *pCur, int N){
+  struct spellfix1_row *aNew;
+  assert( N>=pCur->nRow );
+  aNew = sqlite3_realloc(pCur->a, sizeof(pCur->a[0])*N);
+  if( aNew==0 && N>0 ){
+    spellfix1ResetCursor(pCur);
+    sqlite3_free(pCur->a);
+    pCur->nAlloc = 0;
+    pCur->a = 0;
+  }else{
+    pCur->nAlloc = N;
+    pCur->a = aNew;
+  }
+}
+
+
+/*
+** Close a fuzzy-search cursor.
+*/
+static int spellfix1Close(sqlite3_vtab_cursor *cur){
+  spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+  spellfix1ResetCursor(pCur);
+  spellfix1ResizeCursor(pCur, 0);
+  sqlite3_free(pCur->zPattern);
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Search for terms of these forms:
+**
+**   (A)    word MATCH $str
+**   (B)    langid == $langid
+**   (C)    top = $top
+**   (D)    scope = $scope
+**   (E)    distance < $distance
+**   (F)    distance <= $distance
+**
+** The plan number is a bit mask formed with these bits:
+**
+**   0x01   (A) is found
+**   0x02   (B) is found
+**   0x04   (C) is found
+**   0x08   (D) is found
+**   0x10   (E) is found
+**   0x20   (F) is found
+**
+** filter.argv[*] values contains $str, $langid, $top, and $scope,
+** if specified and in that order.
+*/
+static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int iPlan = 0;
+  int iLangTerm = -1;
+  int iTopTerm = -1;
+  int iScopeTerm = -1;
+  int iDistTerm = -1;
+  int i;
+  const struct sqlite3_index_constraint *pConstraint;
+  pConstraint = pIdxInfo->aConstraint;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+
+    /* Terms of the form:  word MATCH $str */
+    if( (iPlan & 1)==0 
+     && pConstraint->iColumn==SPELLFIX_COL_WORD
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH
+    ){
+      iPlan |= 1;
+      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+    }
+
+    /* Terms of the form:  langid = $langid  */
+    if( (iPlan & 2)==0
+     && pConstraint->iColumn==SPELLFIX_COL_LANGID
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 2;
+      iLangTerm = i;
+    }
+
+    /* Terms of the form:  top = $top */
+    if( (iPlan & 4)==0
+     && pConstraint->iColumn==SPELLFIX_COL_TOP
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 4;
+      iTopTerm = i;
+    }
+
+    /* Terms of the form:  scope = $scope */
+    if( (iPlan & 8)==0
+     && pConstraint->iColumn==SPELLFIX_COL_SCOPE
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 8;
+      iScopeTerm = i;
+    }
+
+    /* Terms of the form:  distance < $dist or distance <= $dist */
+    if( (iPlan & (16|32))==0
+     && pConstraint->iColumn==SPELLFIX_COL_DISTANCE
+     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
+          || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
+    ){
+      iPlan |= pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ? 16 : 32;
+      iDistTerm = i;
+    }
+  }
+  if( iPlan&1 ){
+    int idx = 2;
+    pIdxInfo->idxNum = iPlan;
+    if( pIdxInfo->nOrderBy==1
+     && pIdxInfo->aOrderBy[0].iColumn==SPELLFIX_COL_SCORE
+     && pIdxInfo->aOrderBy[0].desc==0
+    ){
+      pIdxInfo->orderByConsumed = 1;  /* Default order by iScore */
+    }
+    if( iPlan&2 ){
+      pIdxInfo->aConstraintUsage[iLangTerm].argvIndex = idx++;
+      pIdxInfo->aConstraintUsage[iLangTerm].omit = 1;
+    }
+    if( iPlan&4 ){
+      pIdxInfo->aConstraintUsage[iTopTerm].argvIndex = idx++;
+      pIdxInfo->aConstraintUsage[iTopTerm].omit = 1;
+    }
+    if( iPlan&8 ){
+      pIdxInfo->aConstraintUsage[iScopeTerm].argvIndex = idx++;
+      pIdxInfo->aConstraintUsage[iScopeTerm].omit = 1;
+    }
+    if( iPlan&(16|32) ){
+      pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = idx++;
+      pIdxInfo->aConstraintUsage[iDistTerm].omit = 1;
+    }
+    pIdxInfo->estimatedCost = (double)10000;
+  }else{
+    pIdxInfo->idxNum = 0;
+    pIdxInfo->estimatedCost = (double)10000000;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Open a new fuzzy-search cursor.
+*/
+static int spellfix1Open(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+  spellfix1_cursor *pCur;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  pCur->pVTab = p;
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+/*
+** Adjust a distance measurement by the words rank in order to show
+** preference to common words.
+*/
+static int spellfix1Score(int iDistance, int iRank){
+  int iLog2;
+  for(iLog2=0; iRank>0; iLog2++, iRank>>=1){}
+  return iDistance + 32 - iLog2;
+}
+
+/*
+** Compare two spellfix1_row objects for sorting purposes in qsort() such
+** that they sort in order of increasing distance.
+*/
+static int spellfix1RowCompare(const void *A, const void *B){
+  const struct spellfix1_row *a = (const struct spellfix1_row*)A;
+  const struct spellfix1_row *b = (const struct spellfix1_row*)B;
+  return a->iScore - b->iScore;
+}
+
+/*
+** A structure used to pass information from spellfix1FilterForMatch()
+** into spellfix1RunQuery().
+*/
+typedef struct MatchQuery {
+  spellfix1_cursor *pCur;          /* The cursor being queried */
+  sqlite3_stmt *pStmt;             /* shadow table query statment */
+  char zHash[SPELLFIX_MX_HASH];    /* The current phonehash for zPattern */
+  const char *zPattern;            /* Transliterated input string */
+  int nPattern;                    /* Length of zPattern */
+  EditDist3FromString *pMatchStr3; /* Original unicode string */
+  EditDist3Config *pConfig3;       /* Edit-distance cost coefficients */
+  const EditDist3Lang *pLang;      /* The selected language coefficients */
+  int iLang;                       /* The language id */
+  int iScope;                      /* Default scope */
+  int iMaxDist;                    /* Maximum allowed edit distance, or -1 */
+  int rc;                          /* Error code */
+  int nRun;                  /* Number of prior runs for the same zPattern */
+  char azPrior[SPELLFIX_MX_RUN][SPELLFIX_MX_HASH];  /* Prior hashes */
+} MatchQuery;
+
+/*
+** Run a query looking for the best matches against zPattern using
+** zHash as the character class seed hash.
+*/
+static void spellfix1RunQuery(MatchQuery *p, const char *zQuery, int nQuery){
+  const char *zK1;
+  const char *zWord;
+  int iDist;
+  int iRank;
+  int iScore;
+  int iWorst = 0;
+  int idx;
+  int idxWorst = -1;
+  int i;
+  int iScope = p->iScope;
+  spellfix1_cursor *pCur = p->pCur;
+  sqlite3_stmt *pStmt = p->pStmt;
+  char zHash1[SPELLFIX_MX_HASH];
+  char zHash2[SPELLFIX_MX_HASH];
+  char *zClass;
+  int nClass;
+  int rc;
+
+  if( pCur->a==0 || p->rc ) return;   /* Prior memory allocation failure */
+  zClass = (char*)phoneticHash((unsigned char*)zQuery, nQuery);
+  if( zClass==0 ){
+    p->rc = SQLITE_NOMEM;
+    return;
+  }
+  nClass = (int)strlen(zClass);
+  if( nClass>SPELLFIX_MX_HASH-2 ){
+    nClass = SPELLFIX_MX_HASH-2;
+    zClass[nClass] = 0;
+  }
+  if( nClass<=iScope ){
+    if( nClass>2 ){
+      iScope = nClass-1;
+    }else{
+      iScope = nClass;
+    }
+  }
+  memcpy(zHash1, zClass, iScope);
+  sqlite3_free(zClass);
+  zHash1[iScope] = 0;
+  memcpy(zHash2, zHash1, iScope);
+  zHash2[iScope] = 'Z';
+  zHash2[iScope+1] = 0;
+#if SPELLFIX_MX_RUN>1
+  for(i=0; i<p->nRun; i++){
+    if( strcmp(p->azPrior[i], zHash1)==0 ) return;
+  }
+#endif
+  assert( p->nRun<SPELLFIX_MX_RUN );
+  memcpy(p->azPrior[p->nRun++], zHash1, iScope+1);
+  if( sqlite3_bind_text(pStmt, 1, zHash1, -1, SQLITE_STATIC)==SQLITE_NOMEM
+   || sqlite3_bind_text(pStmt, 2, zHash2, -1, SQLITE_STATIC)==SQLITE_NOMEM
+  ){
+    p->rc = SQLITE_NOMEM;
+    return;
+  }
+#if SPELLFIX_MX_RUN>1
+  for(i=0; i<pCur->nRow; i++){
+    if( pCur->a[i].iScore>iWorst ){
+      iWorst = pCur->a[i].iScore;
+      idxWorst = i;
+    }
+  }
+#endif
+  while( sqlite3_step(pStmt)==SQLITE_ROW ){
+    int iMatchlen = -1;
+    iRank = sqlite3_column_int(pStmt, 2);
+    if( p->pMatchStr3 ){
+      int nWord = sqlite3_column_bytes(pStmt, 1);
+      zWord = (const char*)sqlite3_column_text(pStmt, 1);
+      iDist = editDist3Core(p->pMatchStr3, zWord, nWord, p->pLang, &iMatchlen);
+    }else{
+      zK1 = (const char*)sqlite3_column_text(pStmt, 3);
+      if( zK1==0 ) continue;
+      iDist = editdist1(p->zPattern, zK1, 0);
+    }
+    if( iDist<0 ){
+      p->rc = SQLITE_NOMEM;
+      break;
+    }
+    pCur->nSearch++;
+    iScore = spellfix1Score(iDist,iRank);
+    if( p->iMaxDist>=0 ){
+      if( iDist>p->iMaxDist ) continue;
+      if( pCur->nRow>=pCur->nAlloc-1 ){
+        spellfix1ResizeCursor(pCur, pCur->nAlloc*2 + 10);
+        if( pCur->a==0 ) break;
+      }
+      idx = pCur->nRow;
+    }else if( pCur->nRow<pCur->nAlloc ){
+      idx = pCur->nRow;
+    }else if( iScore<iWorst ){
+      idx = idxWorst;
+      sqlite3_free(pCur->a[idx].zWord);
+    }else{
+      continue;
+    }
+    pCur->a[idx].zWord = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 1));
+    if( pCur->a[idx].zWord==0 ){
+      p->rc = SQLITE_NOMEM;
+      break;
+    }
+    pCur->a[idx].iRowid = sqlite3_column_int64(pStmt, 0);
+    pCur->a[idx].iRank = iRank;
+    pCur->a[idx].iDistance = iDist;
+    pCur->a[idx].iScore = iScore;
+    pCur->a[idx].iMatchlen = iMatchlen;
+    memcpy(pCur->a[idx].zHash, zHash1, iScope+1);
+    if( pCur->nRow<pCur->nAlloc ) pCur->nRow++;
+    if( pCur->nRow==pCur->nAlloc ){
+      iWorst = pCur->a[0].iScore;
+      idxWorst = 0;
+      for(i=1; i<pCur->nRow; i++){
+        iScore = pCur->a[i].iScore;
+        if( iWorst<iScore ){
+          iWorst = iScore;
+          idxWorst = i;
+        }
+      }
+    }
+  }
+  rc = sqlite3_reset(pStmt);
+  if( rc ) p->rc = rc;
+}
+
+/*
+** This version of the xFilter method work if the MATCH term is present
+** and we are doing a scan.
+*/
+static int spellfix1FilterForMatch(
+  spellfix1_cursor *pCur,
+  int idxNum,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zMatchThis;   /* RHS of the MATCH operator */
+  EditDist3FromString *pMatchStr3 = 0; /* zMatchThis as an editdist string */
+  char *zPattern;                    /* Transliteration of zMatchThis */
+  int nPattern;                      /* Length of zPattern */
+  int iLimit = 20;                   /* Max number of rows of output */
+  int iScope = 3;                    /* Use this many characters of zClass */
+  int iLang = 0;                     /* Language code */
+  char *zSql;                        /* SQL of shadow table query */
+  sqlite3_stmt *pStmt = 0;           /* Shadow table query */
+  int rc;                            /* Result code */
+  int idx = 1;                       /* Next available filter parameter */
+  spellfix1_vtab *p = pCur->pVTab;   /* The virtual table that owns pCur */
+  MatchQuery x;                      /* For passing info to RunQuery() */
+
+  /* Load the cost table if we have not already done so */
+  if( p->zCostTable!=0 && p->pConfig3==0 ){
+    p->pConfig3 = sqlite3_malloc( sizeof(p->pConfig3[0]) );
+    if( p->pConfig3==0 ) return SQLITE_NOMEM;
+    memset(p->pConfig3, 0, sizeof(p->pConfig3[0]));
+    rc = editDist3ConfigLoad(p->pConfig3, p->db, p->zCostTable);
+    if( rc ) return rc;
+  }
+  memset(&x, 0, sizeof(x));
+  x.iScope = 3;  /* Default scope if none specified by "WHERE scope=N" */
+  x.iMaxDist = -1;   /* Maximum allowed edit distance */
+
+  if( idxNum&2 ){
+    iLang = sqlite3_value_int(argv[idx++]);
+  }
+  if( idxNum&4 ){
+    iLimit = sqlite3_value_int(argv[idx++]);
+    if( iLimit<1 ) iLimit = 1;
+  }
+  if( idxNum&8 ){
+    x.iScope = sqlite3_value_int(argv[idx++]);
+    if( x.iScope<1 ) x.iScope = 1;
+    if( x.iScope>SPELLFIX_MX_HASH-2 ) x.iScope = SPELLFIX_MX_HASH-2;
+  }
+  if( idxNum&(16|32) ){
+    x.iMaxDist = sqlite3_value_int(argv[idx++]);
+    if( idxNum&16 ) x.iMaxDist--;
+    if( x.iMaxDist<0 ) x.iMaxDist = 0;
+  }
+  spellfix1ResetCursor(pCur);
+  spellfix1ResizeCursor(pCur, iLimit);
+  zMatchThis = sqlite3_value_text(argv[0]);
+  if( zMatchThis==0 ) return SQLITE_OK;
+  if( p->pConfig3 ){
+    x.pLang = editDist3FindLang(p->pConfig3, iLang);
+    pMatchStr3 = editDist3FromStringNew(x.pLang, (const char*)zMatchThis, -1);
+    if( pMatchStr3==0 ){
+      x.rc = SQLITE_NOMEM;
+      goto filter_exit;
+    }
+  }else{
+    x.pLang = 0;
+  }
+  zPattern = (char*)transliterate(zMatchThis, sqlite3_value_bytes(argv[0]));
+  sqlite3_free(pCur->zPattern);
+  pCur->zPattern = zPattern;
+  if( zPattern==0 ){
+    x.rc = SQLITE_NOMEM;
+    goto filter_exit;
+  }
+  nPattern = (int)strlen(zPattern);
+  if( zPattern[nPattern-1]=='*' ) nPattern--;
+  zSql = sqlite3_mprintf(
+     "SELECT id, word, rank, k1"
+     "  FROM \"%w\".\"%w_vocab\""
+     " WHERE langid=%d AND k2>=?1 AND k2<?2",
+     p->zDbName, p->zTableName, iLang
+  );
+  if( zSql==0 ){
+    x.rc = SQLITE_NOMEM;
+    pStmt = 0;
+    goto filter_exit;
+  }
+  rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+  sqlite3_free(zSql);
+  pCur->iLang = iLang;
+  x.pCur = pCur;
+  x.pStmt = pStmt;
+  x.zPattern = zPattern;
+  x.nPattern = nPattern;
+  x.pMatchStr3 = pMatchStr3;
+  x.iLang = iLang;
+  x.rc = rc;
+  x.pConfig3 = p->pConfig3;
+  if( x.rc==SQLITE_OK ){
+    spellfix1RunQuery(&x, zPattern, nPattern);
+  }
+
+  if( pCur->a ){
+    qsort(pCur->a, pCur->nRow, sizeof(pCur->a[0]), spellfix1RowCompare);
+    pCur->iTop = iLimit;
+    pCur->iScope = iScope;
+  }else{
+    x.rc = SQLITE_NOMEM;
+  }
+
+filter_exit:
+  sqlite3_finalize(pStmt);
+  editDist3FromStringDelete(pMatchStr3);
+  return x.rc;
+}
+
+/*
+** This version of xFilter handles a full-table scan case
+*/
+static int spellfix1FilterForFullScan(
+  spellfix1_cursor *pCur,
+  int idxNum,
+  int argc,
+  sqlite3_value **argv
+){
+  int rc;
+  char *zSql;
+  spellfix1_vtab *pVTab = pCur->pVTab;
+  spellfix1ResetCursor(pCur);
+  zSql = sqlite3_mprintf(
+     "SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"",
+     pVTab->zDbName, pVTab->zTableName);
+  if( zSql==0 ) return SQLITE_NOMEM;
+  rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pFullScan, 0);
+  sqlite3_free(zSql);
+  pCur->nRow = pCur->iRow = 0;
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_step(pCur->pFullScan);
+    if( rc==SQLITE_ROW ){ pCur->iRow = -1; rc = SQLITE_OK; }
+    if( rc==SQLITE_DONE ){ rc = SQLITE_OK; }
+  }else{
+    pCur->iRow = 0;
+  }
+  return rc;
+}
+
+
+/*
+** Called to "rewind" a cursor back to the beginning so that
+** it starts its output over again.  Always called at least once
+** prior to any spellfix1Column, spellfix1Rowid, or spellfix1Eof call.
+*/
+static int spellfix1Filter(
+  sqlite3_vtab_cursor *cur, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+  int rc;
+  if( idxNum & 1 ){
+    rc = spellfix1FilterForMatch(pCur, idxNum, argc, argv);
+  }else{
+    rc = spellfix1FilterForFullScan(pCur, idxNum, argc, argv);
+  }
+  return rc;
+}
+
+
+/*
+** Advance a cursor to its next row of output
+*/
+static int spellfix1Next(sqlite3_vtab_cursor *cur){
+  spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+  int rc = SQLITE_OK;
+  if( pCur->iRow < pCur->nRow ){
+    if( pCur->pFullScan ){
+      rc = sqlite3_step(pCur->pFullScan);
+      if( rc!=SQLITE_ROW ) pCur->iRow = pCur->nRow;
+      if( rc==SQLITE_ROW || rc==SQLITE_DONE ) rc = SQLITE_OK;
+    }else{
+      pCur->iRow++;
+    }
+  }
+  return rc;
+}
+
+/*
+** Return TRUE if we are at the end-of-file
+*/
+static int spellfix1Eof(sqlite3_vtab_cursor *cur){
+  spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+  return pCur->iRow>=pCur->nRow;
+}
+
+/*
+** Return columns from the current row.
+*/
+static int spellfix1Column(
+  sqlite3_vtab_cursor *cur,
+  sqlite3_context *ctx,
+  int i
+){
+  spellfix1_cursor *pCur = (spellfix1_cursor*)cur;
+  if( pCur->pFullScan ){
+    if( i<=SPELLFIX_COL_LANGID ){
+      sqlite3_result_value(ctx, sqlite3_column_value(pCur->pFullScan, i));
+    }else{
+      sqlite3_result_null(ctx);
+    }
+    return SQLITE_OK;
+  }
+  switch( i ){
+    case SPELLFIX_COL_WORD: {
+      sqlite3_result_text(ctx, pCur->a[pCur->iRow].zWord, -1, SQLITE_STATIC);
+      break;
+    }
+    case SPELLFIX_COL_RANK: {
+      sqlite3_result_int(ctx, pCur->a[pCur->iRow].iRank);
+      break;
+    }
+    case SPELLFIX_COL_DISTANCE: {
+      sqlite3_result_int(ctx, pCur->a[pCur->iRow].iDistance);
+      break;
+    }
+    case SPELLFIX_COL_LANGID: {
+      sqlite3_result_int(ctx, pCur->iLang);
+      break;
+    }
+    case SPELLFIX_COL_SCORE: {
+      sqlite3_result_int(ctx, pCur->a[pCur->iRow].iScore);
+      break;
+    }
+    case SPELLFIX_COL_MATCHLEN: {
+      int iMatchlen = pCur->a[pCur->iRow].iMatchlen;
+      if( iMatchlen<0 ){
+        int nPattern = (int)strlen(pCur->zPattern);
+        char *zWord = pCur->a[pCur->iRow].zWord;
+        int nWord = (int)strlen(zWord);
+
+        if( nPattern>0 && pCur->zPattern[nPattern-1]=='*' ){
+          char *zTranslit;
+          int res;
+          zTranslit = (char *)transliterate((unsigned char *)zWord, nWord);
+          if( !zTranslit ) return SQLITE_NOMEM;
+          res = editdist1(pCur->zPattern, zTranslit, &iMatchlen);
+          sqlite3_free(zTranslit);
+          if( res<0 ) return SQLITE_NOMEM;
+          iMatchlen = translen_to_charlen(zWord, nWord, iMatchlen);
+        }else{
+          iMatchlen = utf8Charlen(zWord, nWord);
+        }
+      }
+
+      sqlite3_result_int(ctx, iMatchlen);
+      break;
+    }
+    case SPELLFIX_COL_PHONEHASH: {
+      sqlite3_result_text(ctx, pCur->a[pCur->iRow].zHash, -1, SQLITE_STATIC);
+      break;
+    }
+    case SPELLFIX_COL_TOP: {
+      sqlite3_result_int(ctx, pCur->iTop);
+      break;
+    }
+    case SPELLFIX_COL_SCOPE: {
+      sqlite3_result_int(ctx, pCur->iScope);
+      break;
+    }
+    case SPELLFIX_COL_SRCHCNT: {
+      sqlite3_result_int(ctx, pCur->nSearch);
+      break;
+    }
+    default: {
+      sqlite3_result_null(ctx);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The rowid.
+*/
+static int spellfix1Rowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  spellfix1_cursor *pCur = (spellfix1_cursor*)cur;
+  if( pCur->pFullScan ){
+    *pRowid = sqlite3_column_int64(pCur->pFullScan, 4);
+  }else{
+    *pRowid = pCur->a[pCur->iRow].iRowid;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The xUpdate() method.
+*/
+static int spellfix1Update(
+  sqlite3_vtab *pVTab,
+  int argc,
+  sqlite3_value **argv,
+  sqlite_int64 *pRowid
+){
+  int rc = SQLITE_OK;
+  sqlite3_int64 rowid, newRowid;
+  spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+  sqlite3 *db = p->db;
+
+  if( argc==1 ){
+    /* A delete operation on the rowid given by argv[0] */
+    rowid = *pRowid = sqlite3_value_int64(argv[0]);
+    spellfix1DbExec(&rc, db, "DELETE FROM \"%w\".\"%w_vocab\" "
+                           " WHERE id=%lld",
+                  p->zDbName, p->zTableName, rowid);
+  }else{
+    const unsigned char *zWord = sqlite3_value_text(argv[SPELLFIX_COL_WORD+2]);
+    int nWord = sqlite3_value_bytes(argv[SPELLFIX_COL_WORD+2]);
+    int iLang = sqlite3_value_int(argv[SPELLFIX_COL_LANGID+2]);
+    int iRank = sqlite3_value_int(argv[SPELLFIX_COL_RANK+2]);
+    const unsigned char *zSoundslike =
+           sqlite3_value_text(argv[SPELLFIX_COL_SOUNDSLIKE+2]);
+    int nSoundslike = sqlite3_value_bytes(argv[SPELLFIX_COL_SOUNDSLIKE+2]);
+    char *zK1, *zK2;
+    int i;
+    char c;
+
+    if( zWord==0 ){
+      /* Inserts of the form:  INSERT INTO table(command) VALUES('xyzzy');
+      ** cause zWord to be NULL, so we look at the "command" column to see
+      ** what special actions to take */
+      const char *zCmd = 
+         (const char*)sqlite3_value_text(argv[SPELLFIX_COL_COMMAND+2]);
+      if( zCmd==0 ){
+        pVTab->zErrMsg = sqlite3_mprintf("%s.word may not be NULL",
+                                         p->zTableName);
+        return SQLITE_CONSTRAINT_NOTNULL;
+      }
+      if( strcmp(zCmd,"reset")==0 ){
+        /* Reset the  edit cost table (if there is one). */
+        editDist3ConfigDelete(p->pConfig3);
+        p->pConfig3 = 0;
+        return SQLITE_OK;
+      }
+      if( strncmp(zCmd,"edit_cost_table=",16)==0 ){
+        editDist3ConfigDelete(p->pConfig3);
+        p->pConfig3 = 0;
+        sqlite3_free(p->zCostTable);
+        p->zCostTable = spellfix1Dequote(zCmd+16);
+        if( p->zCostTable==0 ) return SQLITE_NOMEM;
+        if( p->zCostTable[0]==0 || sqlite3_stricmp(p->zCostTable,"null")==0 ){
+          sqlite3_free(p->zCostTable);
+          p->zCostTable = 0;
+        }
+        return SQLITE_OK;
+      }
+      pVTab->zErrMsg = sqlite3_mprintf("unknown value for %s.command: \"%w\"",
+                                       p->zTableName, zCmd);
+      return SQLITE_ERROR;
+    }
+    if( iRank<1 ) iRank = 1;
+    if( zSoundslike ){
+      zK1 = (char*)transliterate(zSoundslike, nSoundslike);
+    }else{
+      zK1 = (char*)transliterate(zWord, nWord);
+    }
+    if( zK1==0 ) return SQLITE_NOMEM;
+    for(i=0; (c = zK1[i])!=0; i++){
+       if( c>='A' && c<='Z' ) zK1[i] += 'a' - 'A';
+    }
+    zK2 = (char*)phoneticHash((const unsigned char*)zK1, i);
+    if( zK2==0 ){
+      sqlite3_free(zK1);
+      return SQLITE_NOMEM;
+    }
+    if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
+      spellfix1DbExec(&rc, db,
+             "INSERT INTO \"%w\".\"%w_vocab\"(rank,langid,word,k1,k2) "
+             "VALUES(%d,%d,%Q,%Q,%Q)",
+             p->zDbName, p->zTableName,
+             iRank, iLang, zWord, zK1, zK2
+      );
+      *pRowid = sqlite3_last_insert_rowid(db);
+    }else{
+      rowid = sqlite3_value_int64(argv[0]);
+      newRowid = *pRowid = sqlite3_value_int64(argv[1]);
+      spellfix1DbExec(&rc, db,
+             "UPDATE \"%w\".\"%w_vocab\" SET id=%lld, rank=%d, langid=%d,"
+             " word=%Q, k1=%Q, k2=%Q WHERE id=%lld",
+             p->zDbName, p->zTableName, newRowid, iRank, iLang,
+             zWord, zK1, zK2, rowid
+      );
+    }
+    sqlite3_free(zK1);
+    sqlite3_free(zK2);
+  }
+  return rc;
+}
+
+/*
+** Rename the spellfix1 table.
+*/
+static int spellfix1Rename(sqlite3_vtab *pVTab, const char *zNew){
+  spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+  sqlite3 *db = p->db;
+  int rc = SQLITE_OK;
+  char *zNewName = sqlite3_mprintf("%s", zNew);
+  if( zNewName==0 ){
+    return SQLITE_NOMEM;
+  }
+  spellfix1DbExec(&rc, db, 
+     "ALTER TABLE \"%w\".\"%w_vocab\" RENAME TO \"%w_vocab\"",
+     p->zDbName, p->zTableName, zNewName
+  );
+  if( rc==SQLITE_OK ){
+    sqlite3_free(p->zTableName);
+    p->zTableName = zNewName;
+  }else{
+    sqlite3_free(zNewName);
+  }
+  return rc;
+}
+
+
+/*
+** A virtual table module that provides fuzzy search.
+*/
+static sqlite3_module spellfix1Module = {
+  0,                       /* iVersion */
+  spellfix1Create,         /* xCreate - handle CREATE VIRTUAL TABLE */
+  spellfix1Connect,        /* xConnect - reconnected to an existing table */
+  spellfix1BestIndex,      /* xBestIndex - figure out how to do a query */
+  spellfix1Disconnect,     /* xDisconnect - close a connection */
+  spellfix1Destroy,        /* xDestroy - handle DROP TABLE */
+  spellfix1Open,           /* xOpen - open a cursor */
+  spellfix1Close,          /* xClose - close a cursor */
+  spellfix1Filter,         /* xFilter - configure scan constraints */
+  spellfix1Next,           /* xNext - advance a cursor */
+  spellfix1Eof,            /* xEof - check for end of scan */
+  spellfix1Column,         /* xColumn - read data */
+  spellfix1Rowid,          /* xRowid - read data */
+  spellfix1Update,         /* xUpdate */
+  0,                       /* xBegin */
+  0,                       /* xSync */
+  0,                       /* xCommit */
+  0,                       /* xRollback */
+  0,                       /* xFindMethod */
+  spellfix1Rename,         /* xRename */
+};
+
+/*
+** Register the various functions and the virtual table.
+*/
+static int spellfix1Register(sqlite3 *db){
+  int rc = SQLITE_OK;
+  int i;
+  rc = sqlite3_create_function(db, "spellfix1_translit", 1, SQLITE_UTF8, 0,
+                                  transliterateSqlFunc, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "spellfix1_editdist", 2, SQLITE_UTF8, 0,
+                                  editdistSqlFunc, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "spellfix1_phonehash", 1, SQLITE_UTF8, 0,
+                                  phoneticHashSqlFunc, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "spellfix1_scriptcode", 1, SQLITE_UTF8, 0,
+                                  scriptCodeSqlFunc, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = editDist3Install(db);
+  }
+
+  /* Verify sanity of the translit[] table */
+  for(i=0; i<sizeof(translit)/sizeof(translit[0])-1; i++){
+    assert( translit[i].cFrom<translit[i+1].cFrom );
+  }
+
+  return rc;
+}
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Extension load function.
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_spellfix_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  return spellfix1Register(db);
+#endif
+  return SQLITE_OK;
+}
diff --git a/lib/libsqlite3/ext/misc/wholenumber.c b/lib/libsqlite3/ext/misc/wholenumber.c
new file mode 100644
index 00000000000..63369c6ac47
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/wholenumber.c
@@ -0,0 +1,274 @@
+/*
+** 2011 April 02
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file implements a virtual table that returns the whole numbers
+** between 1 and 4294967295, inclusive.
+**
+** Example:
+**
+**     CREATE VIRTUAL TABLE nums USING wholenumber;
+**     SELECT value FROM nums WHERE value<10;
+**
+** Results in:
+**
+**     1 2 3 4 5 6 7 8 9
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+
+/* A wholenumber cursor object */
+typedef struct wholenumber_cursor wholenumber_cursor;
+struct wholenumber_cursor {
+  sqlite3_vtab_cursor base;  /* Base class - must be first */
+  sqlite3_int64 iValue;      /* Current value */
+  sqlite3_int64 mxValue;     /* Maximum value */
+};
+
+/* Methods for the wholenumber module */
+static int wholenumberConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  sqlite3_vtab *pNew;
+  pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
+  if( pNew==0 ) return SQLITE_NOMEM;
+  sqlite3_declare_vtab(db, "CREATE TABLE x(value)");
+  memset(pNew, 0, sizeof(*pNew));
+  return SQLITE_OK;
+}
+/* Note that for this virtual table, the xCreate and xConnect
+** methods are identical. */
+
+static int wholenumberDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+/* The xDisconnect and xDestroy methods are also the same */
+
+
+/*
+** Open a new wholenumber cursor.
+*/
+static int wholenumberOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
+  wholenumber_cursor *pCur;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+/*
+** Close a wholenumber cursor.
+*/
+static int wholenumberClose(sqlite3_vtab_cursor *cur){
+  sqlite3_free(cur);
+  return SQLITE_OK;
+}
+
+
+/*
+** Advance a cursor to its next row of output
+*/
+static int wholenumberNext(sqlite3_vtab_cursor *cur){
+  wholenumber_cursor *pCur = (wholenumber_cursor*)cur;
+  pCur->iValue++;
+  return SQLITE_OK;
+}
+
+/*
+** Return the value associated with a wholenumber.
+*/
+static int wholenumberColumn(
+  sqlite3_vtab_cursor *cur,
+  sqlite3_context *ctx,
+  int i
+){
+  wholenumber_cursor *pCur = (wholenumber_cursor*)cur;
+  sqlite3_result_int64(ctx, pCur->iValue);
+  return SQLITE_OK;
+}
+
+/*
+** The rowid.
+*/
+static int wholenumberRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  wholenumber_cursor *pCur = (wholenumber_cursor*)cur;
+  *pRowid = pCur->iValue;
+  return SQLITE_OK;
+}
+
+/*
+** When the wholenumber_cursor.rLimit value is 0 or less, that is a signal
+** that the cursor has nothing more to output.
+*/
+static int wholenumberEof(sqlite3_vtab_cursor *cur){
+  wholenumber_cursor *pCur = (wholenumber_cursor*)cur;
+  return pCur->iValue>pCur->mxValue || pCur->iValue==0;
+}
+
+/*
+** Called to "rewind" a cursor back to the beginning so that
+** it starts its output over again.  Always called at least once
+** prior to any wholenumberColumn, wholenumberRowid, or wholenumberEof call.
+**
+**    idxNum   Constraints
+**    ------   ---------------------
+**      0      (none)
+**      1      value > $argv0
+**      2      value >= $argv0
+**      4      value < $argv0
+**      8      value <= $argv0
+**
+**      5      value > $argv0 AND value < $argv1
+**      6      value >= $argv0 AND value < $argv1
+**      9      value > $argv0 AND value <= $argv1
+**     10      value >= $argv0 AND value <= $argv1
+*/
+static int wholenumberFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  wholenumber_cursor *pCur = (wholenumber_cursor *)pVtabCursor;
+  sqlite3_int64 v;
+  int i = 0;
+  pCur->iValue = 1;
+  pCur->mxValue = 0xffffffff;  /* 4294967295 */
+  if( idxNum & 3 ){
+    v = sqlite3_value_int64(argv[0]) + (idxNum&1);
+    if( v>pCur->iValue && v<=pCur->mxValue ) pCur->iValue = v;
+    i++;
+  }
+  if( idxNum & 12 ){
+    v = sqlite3_value_int64(argv[i]) - ((idxNum>>2)&1);
+    if( v>=pCur->iValue && v<pCur->mxValue ) pCur->mxValue = v;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Search for terms of these forms:
+**
+**  (1)  value > $value
+**  (2)  value >= $value
+**  (4)  value < $value
+**  (8)  value <= $value
+**
+** idxNum is an ORed combination of 1 or 2 with 4 or 8.
+*/
+static int wholenumberBestIndex(
+  sqlite3_vtab *tab,
+  sqlite3_index_info *pIdxInfo
+){
+  int i;
+  int idxNum = 0;
+  int argvIdx = 1;
+  int ltIdx = -1;
+  int gtIdx = -1;
+  const struct sqlite3_index_constraint *pConstraint;
+  pConstraint = pIdxInfo->aConstraint;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( (idxNum & 3)==0 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_GT ){
+      idxNum |= 1;
+      ltIdx = i;
+    }
+    if( (idxNum & 3)==0 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_GE ){
+      idxNum |= 2;
+      ltIdx = i;
+    }
+    if( (idxNum & 12)==0 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ){
+      idxNum |= 4;
+      gtIdx = i;
+    }
+    if( (idxNum & 12)==0 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE ){
+      idxNum |= 8;
+      gtIdx = i;
+    }
+  }
+  pIdxInfo->idxNum = idxNum;
+  if( ltIdx>=0 ){
+    pIdxInfo->aConstraintUsage[ltIdx].argvIndex = argvIdx++;
+    pIdxInfo->aConstraintUsage[ltIdx].omit = 1;
+  }
+  if( gtIdx>=0 ){
+    pIdxInfo->aConstraintUsage[gtIdx].argvIndex = argvIdx;
+    pIdxInfo->aConstraintUsage[gtIdx].omit = 1;
+  }
+  if( pIdxInfo->nOrderBy==1
+   && pIdxInfo->aOrderBy[0].desc==0
+  ){
+    pIdxInfo->orderByConsumed = 1;
+  }
+  if( (idxNum & 12)==0 ){
+    pIdxInfo->estimatedCost = (double)100000000;
+  }else if( (idxNum & 3)==0 ){
+    pIdxInfo->estimatedCost = (double)5;
+  }else{
+    pIdxInfo->estimatedCost = (double)1;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that provides read-only access to a
+** Tcl global variable namespace.
+*/
+static sqlite3_module wholenumberModule = {
+  0,                         /* iVersion */
+  wholenumberConnect,
+  wholenumberConnect,
+  wholenumberBestIndex,
+  wholenumberDisconnect, 
+  wholenumberDisconnect,
+  wholenumberOpen,           /* xOpen - open a cursor */
+  wholenumberClose,          /* xClose - close a cursor */
+  wholenumberFilter,         /* xFilter - configure scan constraints */
+  wholenumberNext,           /* xNext - advance a cursor */
+  wholenumberEof,            /* xEof - check for end of scan */
+  wholenumberColumn,         /* xColumn - read data */
+  wholenumberRowid,          /* xRowid - read data */
+  0,                         /* xUpdate */
+  0,                         /* xBegin */
+  0,                         /* xSync */
+  0,                         /* xCommit */
+  0,                         /* xRollback */
+  0,                         /* xFindMethod */
+  0,                         /* xRename */
+};
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_wholenumber_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  rc = sqlite3_create_module(db, "wholenumber", &wholenumberModule, 0);
+#endif
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/rtree/rtree.c b/lib/libsqlite3/ext/rtree/rtree.c
index 731cb32be05..16a316f400c 100644
--- a/lib/libsqlite3/ext/rtree/rtree.c
+++ b/lib/libsqlite3/ext/rtree/rtree.c
@@ -2665,7 +2665,7 @@ static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){
   RtreeNode *pRoot;               /* Root node of rtree structure */
 
 
-  /* Obtain a reference to the root node to initialise Rtree.iDepth */
+  /* Obtain a reference to the root node to initialize Rtree.iDepth */
   rc = nodeAcquire(pRtree, 1, 0, &pRoot);
 
   /* Obtain a reference to the leaf node that contains the entry 
@@ -3049,7 +3049,8 @@ static int getIntFromStmt(sqlite3 *db, const char *zSql, int *piVal){
 static int getNodeSize(
   sqlite3 *db,                    /* Database handle */
   Rtree *pRtree,                  /* Rtree handle */
-  int isCreate                    /* True for xCreate, false for xConnect */
+  int isCreate,                   /* True for xCreate, false for xConnect */
+  char **pzErr                    /* OUT: Error message, if any */
 ){
   int rc;
   char *zSql;
@@ -3062,6 +3063,8 @@ static int getNodeSize(
       if( (4+pRtree->nBytesPerCell*RTREE_MAXCELLS)<pRtree->iNodeSize ){
         pRtree->iNodeSize = 4+pRtree->nBytesPerCell*RTREE_MAXCELLS;
       }
+    }else{
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
     }
   }else{
     zSql = sqlite3_mprintf(
@@ -3069,6 +3072,9 @@ static int getNodeSize(
         pRtree->zDb, pRtree->zName
     );
     rc = getIntFromStmt(db, zSql, &pRtree->iNodeSize);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+    }
   }
 
   sqlite3_free(zSql);
@@ -3132,7 +3138,7 @@ static int rtreeInit(
   memcpy(pRtree->zName, argv[2], nName);
 
   /* Figure out the node size to use. */
-  rc = getNodeSize(db, pRtree, isCreate);
+  rc = getNodeSize(db, pRtree, isCreate, pzErr);
 
   /* Create/Connect to the underlying relational database schema. If
   ** that is successful, call sqlite3_declare_vtab() to configure
diff --git a/lib/libsqlite3/ext/rtree/rtree1.test b/lib/libsqlite3/ext/rtree/rtree1.test
index e3c7d68e82d..275b13264f7 100644
--- a/lib/libsqlite3/ext/rtree/rtree1.test
+++ b/lib/libsqlite3/ext/rtree/rtree1.test
@@ -17,6 +17,7 @@ if {![info exists testdir]} {
 }
 source [file join [file dirname [info script]] rtree_util.tcl]
 source $testdir/tester.tcl
+set testprefix rtree1
 
 # Test plan:
 #
diff --git a/lib/libsqlite3/ext/rtree/rtree5.test b/lib/libsqlite3/ext/rtree/rtree5.test
index 8990772356a..8ff90b0cb70 100644
--- a/lib/libsqlite3/ext/rtree/rtree5.test
+++ b/lib/libsqlite3/ext/rtree/rtree5.test
@@ -61,7 +61,7 @@ do_test rtree5-1.9 {
 do_test rtree5-1.10 { 
   execsql { SELECT (1<<31)-5, (1<<31)-1, -1*(1<<31), -1*(1<<31)+5 }
 } {2147483643 2147483647 -2147483648 -2147483643}
-do_test rtree5-1.10 { 
+do_test rtree5-1.11 { 
   execsql { 
     INSERT INTO t1 VALUES(2, (1<<31)-5, (1<<31)-1, -1*(1<<31), -1*(1<<31)+5) 
   }
diff --git a/lib/libsqlite3/src/analyze.c b/lib/libsqlite3/src/analyze.c
index 632fdc1ac14..9a3e9597db0 100644
--- a/lib/libsqlite3/src/analyze.c
+++ b/lib/libsqlite3/src/analyze.c
@@ -473,7 +473,7 @@ static void analyzeOneTable(
     /* Do not gather statistics on views or virtual tables */
     return;
   }
-  if( memcmp(pTab->zName, "sqlite_", 7)==0 ){
+  if( sqlite3_strnicmp(pTab->zName, "sqlite_", 7)==0 ){
     /* Do not gather statistics on system tables */
     return;
   }
@@ -883,7 +883,7 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
     if( pIndex==0 ) break;
     pIndex->aiRowEst[i] = v;
     if( *z==' ' ) z++;
-    if( memcmp(z, "unordered", 10)==0 ){
+    if( strcmp(z, "unordered")==0 ){
       pIndex->bUnordered = 1;
       break;
     }
diff --git a/lib/libsqlite3/src/attach.c b/lib/libsqlite3/src/attach.c
index 6682c914754..b8e12199b57 100644
--- a/lib/libsqlite3/src/attach.c
+++ b/lib/libsqlite3/src/attach.c
@@ -109,7 +109,7 @@ static void attachFunc(
     }
   }
 
-  /* Allocate the new entry in the db->aDb[] array and initialise the schema
+  /* Allocate the new entry in the db->aDb[] array and initialize the schema
   ** hash tables.
   */
   if( db->aDb==db->aDbStatic ){
@@ -126,7 +126,7 @@ static void attachFunc(
 
   /* Open the database file. If the btree is successfully opened, use
   ** it to obtain the database schema. At this point the schema may
-  ** or may not be initialised.
+  ** or may not be initialized.
   */
   flags = db->openFlags;
   rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
diff --git a/lib/libsqlite3/src/backup.c b/lib/libsqlite3/src/backup.c
index b234716d61d..252f61cfcaa 100644
--- a/lib/libsqlite3/src/backup.c
+++ b/lib/libsqlite3/src/backup.c
@@ -212,7 +212,12 @@ static int isFatalError(int rc){
 ** page iSrcPg from the source database. Copy this data into the 
 ** destination database.
 */
-static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){
+static int backupOnePage(
+  sqlite3_backup *p,              /* Backup handle */
+  Pgno iSrcPg,                    /* Source database page to backup */
+  const u8 *zSrcData,             /* Source database page data */
+  int bUpdate                     /* True for an update, false otherwise */
+){
   Pager * const pDestPager = sqlite3BtreePager(p->pDest);
   const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);
   int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);
@@ -285,6 +290,9 @@ static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){
       */
       memcpy(zOut, zIn, nCopy);
       ((u8 *)sqlite3PagerGetExtra(pDestPg))[0] = 0;
+      if( iOff==0 && bUpdate==0 ){
+        sqlite3Put4byte(&zOut[28], sqlite3BtreeLastPage(p->pSrc));
+      }
     }
     sqlite3PagerUnref(pDestPg);
   }
@@ -389,9 +397,10 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       const Pgno iSrcPg = p->iNext;                 /* Source page number */
       if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){
         DbPage *pSrcPg;                             /* Source page object */
-        rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
+        rc = sqlite3PagerAcquire(pSrcPager, iSrcPg, &pSrcPg,
+                                 PAGER_ACQUIRE_READONLY);
         if( rc==SQLITE_OK ){
-          rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg));
+          rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0);
           sqlite3PagerUnref(pSrcPg);
         }
       }
@@ -454,7 +463,6 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           nDestTruncate = nSrcPage * (pgszSrc/pgszDest);
         }
         assert( nDestTruncate>0 );
-        sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
 
         if( pgszSrc<pgszDest ){
           /* If the source page-size is smaller than the destination page-size,
@@ -468,6 +476,8 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           */
           const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
           sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
+          Pgno iPg;
+          int nDstPage;
           i64 iOff;
           i64 iEnd;
 
@@ -478,13 +488,26 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
              && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
           ));
 
-          /* This call ensures that all data required to recreate the original
+          /* This block ensures that all data required to recreate the original
           ** database has been stored in the journal for pDestPager and the
           ** journal synced to disk. So at this point we may safely modify
           ** the database file in any way, knowing that if a power failure
           ** occurs, the original database will be reconstructed from the 
           ** journal file.  */
-          rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
+          sqlite3PagerPagecount(pDestPager, &nDstPage);
+          for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){
+            if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){
+              DbPage *pPg;
+              rc = sqlite3PagerGet(pDestPager, iPg, &pPg);
+              if( rc==SQLITE_OK ){
+                rc = sqlite3PagerWrite(pPg);
+                sqlite3PagerUnref(pPg);
+              }
+            }
+          }
+          if( rc==SQLITE_OK ){
+            rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
+          }
 
           /* Write the extra pages and truncate the database file as required */
           iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
@@ -511,6 +534,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
             rc = sqlite3PagerSync(pDestPager);
           }
         }else{
+          sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
           rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
         }
     
@@ -639,7 +663,7 @@ void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){
       int rc;
       assert( p->pDestDb );
       sqlite3_mutex_enter(p->pDestDb->mutex);
-      rc = backupOnePage(p, iPage, aData);
+      rc = backupOnePage(p, iPage, aData, 1);
       sqlite3_mutex_leave(p->pDestDb->mutex);
       assert( rc!=SQLITE_BUSY && rc!=SQLITE_LOCKED );
       if( rc!=SQLITE_OK ){
diff --git a/lib/libsqlite3/src/bitvec.c b/lib/libsqlite3/src/bitvec.c
index 8d805a6fe5e..52184aa964c 100644
--- a/lib/libsqlite3/src/bitvec.c
+++ b/lib/libsqlite3/src/bitvec.c
@@ -72,7 +72,7 @@
 /*
 ** A bitmap is an instance of the following structure.
 **
-** This bitmap records the existance of zero or more bits
+** This bitmap records the existence of zero or more bits
 ** with values between 1 and iSize, inclusive.
 **
 ** There are three possible representations of the bitmap.
diff --git a/lib/libsqlite3/src/btree.c b/lib/libsqlite3/src/btree.c
index 246843b79e3..3ca60583e3c 100644
--- a/lib/libsqlite3/src/btree.c
+++ b/lib/libsqlite3/src/btree.c
@@ -43,6 +43,25 @@ int sqlite3BtreeTrace=1;  /* True to enable tracing */
 */
 #define get2byteNotZero(X)  (((((int)get2byte(X))-1)&0xffff)+1)
 
+/*
+** Values passed as the 5th argument to allocateBtreePage()
+*/
+#define BTALLOC_ANY   0           /* Allocate any page */
+#define BTALLOC_EXACT 1           /* Allocate exact page if possible */
+#define BTALLOC_LE    2           /* Allocate any page <= the parameter */
+
+/*
+** Macro IfNotOmitAV(x) returns (x) if SQLITE_OMIT_AUTOVACUUM is not 
+** defined, or 0 if it is. For example:
+**
+**   bIncrVacuum = IfNotOmitAV(pBtShared->incrVacuum);
+*/
+#ifndef SQLITE_OMIT_AUTOVACUUM
+#define IfNotOmitAV(expr) (expr)
+#else
+#define IfNotOmitAV(expr) 0
+#endif
+
 #ifndef SQLITE_OMIT_SHARED_CACHE
 /*
 ** A list of BtShared objects that are eligible for participation
@@ -557,6 +576,19 @@ static void btreeClearHasContent(BtShared *pBt){
 }
 
 /*
+** Release all of the apPage[] pages for a cursor.
+*/
+static void btreeReleaseAllCursorPages(BtCursor *pCur){
+  int i;
+  for(i=0; i<=pCur->iPage; i++){
+    releasePage(pCur->apPage[i]);
+    pCur->apPage[i] = 0;
+  }
+  pCur->iPage = -1;
+}
+
+
+/*
 ** Save the current cursor position in the variables BtCursor.nKey 
 ** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
 **
@@ -595,12 +627,7 @@ static int saveCursorPosition(BtCursor *pCur){
   assert( !pCur->apPage[0]->intKey || !pCur->pKey );
 
   if( rc==SQLITE_OK ){
-    int i;
-    for(i=0; i<=pCur->iPage; i++){
-      releasePage(pCur->apPage[i]);
-      pCur->apPage[i] = 0;
-    }
-    pCur->iPage = -1;
+    btreeReleaseAllCursorPages(pCur);
     pCur->eState = CURSOR_REQUIRESEEK;
   }
 
@@ -618,11 +645,15 @@ static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
   assert( sqlite3_mutex_held(pBt->mutex) );
   assert( pExcept==0 || pExcept->pBt==pBt );
   for(p=pBt->pCursor; p; p=p->pNext){
-    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) && 
-        p->eState==CURSOR_VALID ){
-      int rc = saveCursorPosition(p);
-      if( SQLITE_OK!=rc ){
-        return rc;
+    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){
+      if( p->eState==CURSOR_VALID ){
+        int rc = saveCursorPosition(p);
+        if( SQLITE_OK!=rc ){
+          return rc;
+        }
+      }else{
+        testcase( p->iPage>0 );
+        btreeReleaseAllCursorPages(p);
       }
     }
   }
@@ -1550,13 +1581,17 @@ static int btreeGetPage(
   BtShared *pBt,       /* The btree */
   Pgno pgno,           /* Number of the page to fetch */
   MemPage **ppPage,    /* Return the page in this parameter */
-  int noContent        /* Do not load page content if true */
+  int noContent,       /* Do not load page content if true */
+  int bReadonly        /* True if a read-only (mmap) page is ok */
 ){
   int rc;
   DbPage *pDbPage;
+  int flags = (noContent ? PAGER_ACQUIRE_NOCONTENT : 0) 
+            | (bReadonly ? PAGER_ACQUIRE_READONLY : 0);
 
+  assert( noContent==0 || bReadonly==0 );
   assert( sqlite3_mutex_held(pBt->mutex) );
-  rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, noContent);
+  rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
   if( rc ) return rc;
   *ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
   return SQLITE_OK;
@@ -1599,9 +1634,10 @@ u32 sqlite3BtreeLastPage(Btree *p){
 ** may remain unchanged, or it may be set to an invalid value.
 */
 static int getAndInitPage(
-  BtShared *pBt,          /* The database file */
-  Pgno pgno,           /* Number of the page to get */
-  MemPage **ppPage     /* Write the page pointer here */
+  BtShared *pBt,                  /* The database file */
+  Pgno pgno,                      /* Number of the page to get */
+  MemPage **ppPage,               /* Write the page pointer here */
+  int bReadonly                   /* True if a read-only (mmap) page is ok */
 ){
   int rc;
   assert( sqlite3_mutex_held(pBt->mutex) );
@@ -1609,7 +1645,7 @@ static int getAndInitPage(
   if( pgno>btreePagecount(pBt) ){
     rc = SQLITE_CORRUPT_BKPT;
   }else{
-    rc = btreeGetPage(pBt, pgno, ppPage, 0);
+    rc = btreeGetPage(pBt, pgno, ppPage, 0, bReadonly);
     if( rc==SQLITE_OK ){
       rc = btreeInitPage(*ppPage);
       if( rc!=SQLITE_OK ){
@@ -1840,6 +1876,7 @@ int sqlite3BtreeOpen(
     rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
                           EXTRA_SIZE, flags, vfsFlags, pageReinit);
     if( rc==SQLITE_OK ){
+      sqlite3PagerSetMmapLimit(pBt->pPager, db->szMmap);
       rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
     }
     if( rc!=SQLITE_OK ){
@@ -2107,6 +2144,19 @@ int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
 }
 
 /*
+** Change the limit on the amount of the database file that may be
+** memory mapped.
+*/
+int sqlite3BtreeSetMmapLimit(Btree *p, sqlite3_int64 szMmap){
+  BtShared *pBt = p->pBt;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  sqlite3PagerSetMmapLimit(pBt->pPager, szMmap);
+  sqlite3BtreeLeave(p);
+  return SQLITE_OK;
+}
+
+/*
 ** Change the way data is synced to disk in order to increase or decrease
 ** how well the database resists damage due to OS crashes and power
 ** failures.  Level 1 is the same as asynchronous (no syncs() occur and
@@ -2210,7 +2260,7 @@ int sqlite3BtreeGetPageSize(Btree *p){
 ** known that the shared b-tree mutex is held, but the mutex on the 
 ** database handle that owns *p is not. In this case if sqlite3BtreeEnter()
 ** were to be called, it might collide with some other operation on the
-** database handle that owns *p, causing undefined behaviour.
+** database handle that owns *p, causing undefined behavior.
 */
 int sqlite3BtreeGetReserveNoMutex(Btree *p){
   assert( sqlite3_mutex_held(p->pBt->mutex) );
@@ -2331,7 +2381,7 @@ static int lockBtree(BtShared *pBt){
   assert( pBt->pPage1==0 );
   rc = sqlite3PagerSharedLock(pBt->pPager);
   if( rc!=SQLITE_OK ) return rc;
-  rc = btreeGetPage(pBt, 1, &pPage1, 0);
+  rc = btreeGetPage(pBt, 1, &pPage1, 0, 0);
   if( rc!=SQLITE_OK ) return rc;
 
   /* Do some checking to help insure the file we opened really is
@@ -2467,6 +2517,29 @@ page1_init_failed:
   return rc;
 }
 
+#ifndef NDEBUG
+/*
+** Return the number of cursors open on pBt. This is for use
+** in assert() expressions, so it is only compiled if NDEBUG is not
+** defined.
+**
+** Only write cursors are counted if wrOnly is true.  If wrOnly is
+** false then all cursors are counted.
+**
+** For the purposes of this routine, a cursor is any cursor that
+** is capable of reading or writing to the databse.  Cursors that
+** have been tripped into the CURSOR_FAULT state are not counted.
+*/
+static int countValidCursors(BtShared *pBt, int wrOnly){
+  BtCursor *pCur;
+  int r = 0;
+  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
+    if( (wrOnly==0 || pCur->wrFlag) && pCur->eState!=CURSOR_FAULT ) r++; 
+  }
+  return r;
+}
+#endif
+
 /*
 ** If there are no outstanding cursors and we are not in the middle
 ** of a transaction but there is a read lock on the database, then
@@ -2477,7 +2550,7 @@ page1_init_failed:
 */
 static void unlockBtreeIfUnused(BtShared *pBt){
   assert( sqlite3_mutex_held(pBt->mutex) );
-  assert( pBt->pCursor==0 || pBt->inTransaction>TRANS_NONE );
+  assert( countValidCursors(pBt,0)==0 || pBt->inTransaction>TRANS_NONE );
   if( pBt->inTransaction==TRANS_NONE && pBt->pPage1!=0 ){
     assert( pBt->pPage1->aData );
     assert( sqlite3PagerRefcount(pBt->pPager)==1 );
@@ -2595,6 +2668,7 @@ int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
   if( p->inTrans==TRANS_WRITE || (p->inTrans==TRANS_READ && !wrflag) ){
     goto trans_begun;
   }
+  assert( IfNotOmitAV(pBt->bDoTruncate)==0 );
 
   /* Write transactions are not possible on a read-only database */
   if( (pBt->btsFlags & BTS_READ_ONLY)!=0 && wrflag ){
@@ -2889,7 +2963,7 @@ static int relocatePage(
   ** iPtrPage.
   */
   if( eType!=PTRMAP_ROOTPAGE ){
-    rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0);
+    rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0, 0);
     if( rc!=SQLITE_OK ){
       return rc;
     }
@@ -2911,24 +2985,23 @@ static int relocatePage(
 static int allocateBtreePage(BtShared *, MemPage **, Pgno *, Pgno, u8);
 
 /*
-** Perform a single step of an incremental-vacuum. If successful,
-** return SQLITE_OK. If there is no work to do (and therefore no
-** point in calling this function again), return SQLITE_DONE.
+** Perform a single step of an incremental-vacuum. If successful, return
+** SQLITE_OK. If there is no work to do (and therefore no point in 
+** calling this function again), return SQLITE_DONE. Or, if an error 
+** occurs, return some other error code.
 **
-** More specificly, this function attempts to re-organize the 
-** database so that the last page of the file currently in use
-** is no longer in use.
+** More specificly, this function attempts to re-organize the database so 
+** that the last page of the file currently in use is no longer in use.
 **
-** If the nFin parameter is non-zero, this function assumes
-** that the caller will keep calling incrVacuumStep() until
-** it returns SQLITE_DONE or an error, and that nFin is the
-** number of pages the database file will contain after this 
-** process is complete.  If nFin is zero, it is assumed that
-** incrVacuumStep() will be called a finite amount of times
-** which may or may not empty the freelist.  A full autovacuum
-** has nFin>0.  A "PRAGMA incremental_vacuum" has nFin==0.
+** Parameter nFin is the number of pages that this database would contain
+** were this function called until it returns SQLITE_DONE.
+**
+** If the bCommit parameter is non-zero, this function assumes that the 
+** caller will keep calling incrVacuumStep() until it returns SQLITE_DONE 
+** or an error. bCommit is passed true for an auto-vacuum-on-commmit 
+** operation, or false for an incremental vacuum.
 */
-static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
+static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg, int bCommit){
   Pgno nFreeList;           /* Number of pages still on the free-list */
   int rc;
 
@@ -2953,15 +3026,15 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
     }
 
     if( eType==PTRMAP_FREEPAGE ){
-      if( nFin==0 ){
+      if( bCommit==0 ){
         /* Remove the page from the files free-list. This is not required
-        ** if nFin is non-zero. In that case, the free-list will be
+        ** if bCommit is non-zero. In that case, the free-list will be
         ** truncated to zero after this function returns, so it doesn't 
         ** matter if it still contains some garbage entries.
         */
         Pgno iFreePg;
         MemPage *pFreePg;
-        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iLastPg, 1);
+        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iLastPg, BTALLOC_EXACT);
         if( rc!=SQLITE_OK ){
           return rc;
         }
@@ -2971,34 +3044,37 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
     } else {
       Pgno iFreePg;             /* Index of free page to move pLastPg to */
       MemPage *pLastPg;
+      u8 eMode = BTALLOC_ANY;   /* Mode parameter for allocateBtreePage() */
+      Pgno iNear = 0;           /* nearby parameter for allocateBtreePage() */
 
-      rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0);
+      rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
 
-      /* If nFin is zero, this loop runs exactly once and page pLastPg
+      /* If bCommit is zero, this loop runs exactly once and page pLastPg
       ** is swapped with the first free page pulled off the free list.
       **
-      ** On the other hand, if nFin is greater than zero, then keep
+      ** On the other hand, if bCommit is greater than zero, then keep
       ** looping until a free-page located within the first nFin pages
       ** of the file is found.
       */
+      if( bCommit==0 ){
+        eMode = BTALLOC_LE;
+        iNear = nFin;
+      }
       do {
         MemPage *pFreePg;
-        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, 0, 0);
+        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iNear, eMode);
         if( rc!=SQLITE_OK ){
           releasePage(pLastPg);
           return rc;
         }
         releasePage(pFreePg);
-      }while( nFin!=0 && iFreePg>nFin );
+      }while( bCommit && iFreePg>nFin );
       assert( iFreePg<iLastPg );
       
-      rc = sqlite3PagerWrite(pLastPg->pDbPage);
-      if( rc==SQLITE_OK ){
-        rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, nFin!=0);
-      }
+      rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, bCommit);
       releasePage(pLastPg);
       if( rc!=SQLITE_OK ){
         return rc;
@@ -3006,30 +3082,40 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
     }
   }
 
-  if( nFin==0 ){
-    iLastPg--;
-    while( iLastPg==PENDING_BYTE_PAGE(pBt)||PTRMAP_ISPAGE(pBt, iLastPg) ){
-      if( PTRMAP_ISPAGE(pBt, iLastPg) ){
-        MemPage *pPg;
-        rc = btreeGetPage(pBt, iLastPg, &pPg, 0);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        rc = sqlite3PagerWrite(pPg->pDbPage);
-        releasePage(pPg);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-      }
+  if( bCommit==0 ){
+    do {
       iLastPg--;
-    }
-    sqlite3PagerTruncateImage(pBt->pPager, iLastPg);
+    }while( iLastPg==PENDING_BYTE_PAGE(pBt) || PTRMAP_ISPAGE(pBt, iLastPg) );
+    pBt->bDoTruncate = 1;
     pBt->nPage = iLastPg;
   }
   return SQLITE_OK;
 }
 
 /*
+** The database opened by the first argument is an auto-vacuum database
+** nOrig pages in size containing nFree free pages. Return the expected 
+** size of the database in pages following an auto-vacuum operation.
+*/
+static Pgno finalDbSize(BtShared *pBt, Pgno nOrig, Pgno nFree){
+  int nEntry;                     /* Number of entries on one ptrmap page */
+  Pgno nPtrmap;                   /* Number of PtrMap pages to be freed */
+  Pgno nFin;                      /* Return value */
+
+  nEntry = pBt->usableSize/5;
+  nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+nEntry)/nEntry;
+  nFin = nOrig - nFree - nPtrmap;
+  if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<PENDING_BYTE_PAGE(pBt) ){
+    nFin--;
+  }
+  while( PTRMAP_ISPAGE(pBt, nFin) || nFin==PENDING_BYTE_PAGE(pBt) ){
+    nFin--;
+  }
+
+  return nFin;
+}
+
+/*
 ** A write-transaction must be opened before calling this function.
 ** It performs a single unit of work towards an incremental vacuum.
 **
@@ -3046,11 +3132,24 @@ int sqlite3BtreeIncrVacuum(Btree *p){
   if( !pBt->autoVacuum ){
     rc = SQLITE_DONE;
   }else{
-    invalidateAllOverflowCache(pBt);
-    rc = incrVacuumStep(pBt, 0, btreePagecount(pBt));
-    if( rc==SQLITE_OK ){
-      rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
-      put4byte(&pBt->pPage1->aData[28], pBt->nPage);
+    Pgno nOrig = btreePagecount(pBt);
+    Pgno nFree = get4byte(&pBt->pPage1->aData[36]);
+    Pgno nFin = finalDbSize(pBt, nOrig, nFree);
+
+    if( nOrig<nFin ){
+      rc = SQLITE_CORRUPT_BKPT;
+    }else if( nFree>0 ){
+      rc = saveAllCursors(pBt, 0, 0);
+      if( rc==SQLITE_OK ){
+        invalidateAllOverflowCache(pBt);
+        rc = incrVacuumStep(pBt, nFin, nOrig, 0);
+      }
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
+        put4byte(&pBt->pPage1->aData[28], pBt->nPage);
+      }
+    }else{
+      rc = SQLITE_DONE;
     }
   }
   sqlite3BtreeLeave(p);
@@ -3077,9 +3176,7 @@ static int autoVacuumCommit(BtShared *pBt){
   if( !pBt->incrVacuum ){
     Pgno nFin;         /* Number of pages in database after autovacuuming */
     Pgno nFree;        /* Number of pages on the freelist initially */
-    Pgno nPtrmap;      /* Number of PtrMap pages to be freed */
     Pgno iFree;        /* The next page to be freed */
-    int nEntry;        /* Number of entries on one ptrmap page */
     Pgno nOrig;        /* Database size before freeing */
 
     nOrig = btreePagecount(pBt);
@@ -3092,26 +3189,20 @@ static int autoVacuumCommit(BtShared *pBt){
     }
 
     nFree = get4byte(&pBt->pPage1->aData[36]);
-    nEntry = pBt->usableSize/5;
-    nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+nEntry)/nEntry;
-    nFin = nOrig - nFree - nPtrmap;
-    if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<PENDING_BYTE_PAGE(pBt) ){
-      nFin--;
-    }
-    while( PTRMAP_ISPAGE(pBt, nFin) || nFin==PENDING_BYTE_PAGE(pBt) ){
-      nFin--;
-    }
+    nFin = finalDbSize(pBt, nOrig, nFree);
     if( nFin>nOrig ) return SQLITE_CORRUPT_BKPT;
-
+    if( nFin<nOrig ){
+      rc = saveAllCursors(pBt, 0, 0);
+    }
     for(iFree=nOrig; iFree>nFin && rc==SQLITE_OK; iFree--){
-      rc = incrVacuumStep(pBt, nFin, iFree);
+      rc = incrVacuumStep(pBt, nFin, iFree, 1);
     }
     if( (rc==SQLITE_DONE || rc==SQLITE_OK) && nFree>0 ){
       rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
       put4byte(&pBt->pPage1->aData[32], 0);
       put4byte(&pBt->pPage1->aData[36], 0);
       put4byte(&pBt->pPage1->aData[28], nFin);
-      sqlite3PagerTruncateImage(pBt->pPager, nFin);
+      pBt->bDoTruncate = 1;
       pBt->nPage = nFin;
     }
     if( rc!=SQLITE_OK ){
@@ -3119,7 +3210,7 @@ static int autoVacuumCommit(BtShared *pBt){
     }
   }
 
-  assert( nRef==sqlite3PagerRefcount(pPager) );
+  assert( nRef>=sqlite3PagerRefcount(pPager) );
   return rc;
 }
 
@@ -3166,6 +3257,9 @@ int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zMaster){
         return rc;
       }
     }
+    if( pBt->bDoTruncate ){
+      sqlite3PagerTruncateImage(pBt->pPager, pBt->nPage);
+    }
 #endif
     rc = sqlite3PagerCommitPhaseOne(pBt->pPager, zMaster, 0);
     sqlite3BtreeLeave(p);
@@ -3181,7 +3275,9 @@ static void btreeEndTransaction(Btree *p){
   BtShared *pBt = p->pBt;
   assert( sqlite3BtreeHoldsMutex(p) );
 
-  btreeClearHasContent(pBt);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  pBt->bDoTruncate = 0;
+#endif
   if( p->inTrans>TRANS_NONE && p->db->activeVdbeCnt>1 ){
     /* If there are other active statements that belong to this database
     ** handle, downgrade to a read-only transaction. The other statements
@@ -3256,6 +3352,7 @@ int sqlite3BtreeCommitPhaseTwo(Btree *p, int bCleanup){
       return rc;
     }
     pBt->inTransaction = TRANS_READ;
+    btreeClearHasContent(pBt);
   }
 
   btreeEndTransaction(p);
@@ -3277,27 +3374,6 @@ int sqlite3BtreeCommit(Btree *p){
   return rc;
 }
 
-#ifndef NDEBUG
-/*
-** Return the number of write-cursors open on this handle. This is for use
-** in assert() expressions, so it is only compiled if NDEBUG is not
-** defined.
-**
-** For the purposes of this routine, a write-cursor is any cursor that
-** is capable of writing to the databse.  That means the cursor was
-** originally opened for writing and the cursor has not be disabled
-** by having its state changed to CURSOR_FAULT.
-*/
-static int countWriteCursors(BtShared *pBt){
-  BtCursor *pCur;
-  int r = 0;
-  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
-    if( pCur->wrFlag && pCur->eState!=CURSOR_FAULT ) r++; 
-  }
-  return r;
-}
-#endif
-
 /*
 ** This routine sets the state to CURSOR_FAULT and the error
 ** code to errCode for every cursor on BtShared that pBtree
@@ -3369,7 +3445,7 @@ int sqlite3BtreeRollback(Btree *p, int tripCode){
     /* The rollback may have destroyed the pPage1->aData value.  So
     ** call btreeGetPage() on page 1 again to make
     ** sure pPage1->aData is set correctly. */
-    if( btreeGetPage(pBt, 1, &pPage1, 0)==SQLITE_OK ){
+    if( btreeGetPage(pBt, 1, &pPage1, 0, 0)==SQLITE_OK ){
       int nPage = get4byte(28+(u8*)pPage1->aData);
       testcase( nPage==0 );
       if( nPage==0 ) sqlite3PagerPagecount(pBt->pPager, &nPage);
@@ -3377,8 +3453,9 @@ int sqlite3BtreeRollback(Btree *p, int tripCode){
       pBt->nPage = nPage;
       releasePage(pPage1);
     }
-    assert( countWriteCursors(pBt)==0 );
+    assert( countValidCursors(pBt, 1)==0 );
     pBt->inTransaction = TRANS_READ;
+    btreeClearHasContent(pBt);
   }
 
   btreeEndTransaction(p);
@@ -3803,7 +3880,7 @@ static int getOverflowPage(
 
   assert( next==0 || rc==SQLITE_DONE );
   if( rc==SQLITE_OK ){
-    rc = btreeGetPage(pBt, ovfl, &pPage, 0);
+    rc = btreeGetPage(pBt, ovfl, &pPage, 0, (ppPage==0));
     assert( rc==SQLITE_OK || pPage==0 );
     if( rc==SQLITE_OK ){
       next = get4byte(pPage->aData);
@@ -4024,7 +4101,9 @@ static int accessPayload(
 
         {
           DbPage *pDbPage;
-          rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage);
+          rc = sqlite3PagerAcquire(pBt->pPager, nextPage, &pDbPage,
+              (eOp==0 ? PAGER_ACQUIRE_READONLY : 0)
+          );
           if( rc==SQLITE_OK ){
             aPayload = sqlite3PagerGetData(pDbPage);
             nextPage = get4byte(aPayload);
@@ -4203,10 +4282,11 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
   assert( cursorHoldsMutex(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
+  assert( pCur->iPage>=0 );
   if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
     return SQLITE_CORRUPT_BKPT;
   }
-  rc = getAndInitPage(pBt, newPgno, &pNewPage);
+  rc = getAndInitPage(pBt, newPgno, &pNewPage, (pCur->wrFlag==0));
   if( rc ) return rc;
   pCur->apPage[i+1] = pNewPage;
   pCur->aiIdx[i+1] = 0;
@@ -4323,7 +4403,7 @@ static int moveToRoot(BtCursor *pCur){
     pCur->eState = CURSOR_INVALID;
     return SQLITE_OK;
   }else{
-    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]);
+    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0], pCur->wrFlag==0);
     if( rc!=SQLITE_OK ){
       pCur->eState = CURSOR_INVALID;
       return rc;
@@ -4853,21 +4933,23 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
 ** an error.  *ppPage and *pPgno are undefined in the event of an error.
 ** Do not invoke sqlite3PagerUnref() on *ppPage if an error is returned.
 **
-** If the "nearby" parameter is not 0, then a (feeble) effort is made to 
+** If the "nearby" parameter is not 0, then an effort is made to 
 ** locate a page close to the page number "nearby".  This can be used in an
 ** attempt to keep related pages close to each other in the database file,
 ** which in turn can make database access faster.
 **
-** If the "exact" parameter is not 0, and the page-number nearby exists 
-** anywhere on the free-list, then it is guarenteed to be returned. This
-** is only used by auto-vacuum databases when allocating a new table.
+** If the eMode parameter is BTALLOC_EXACT and the nearby page exists
+** anywhere on the free-list, then it is guaranteed to be returned.  If
+** eMode is BTALLOC_LT then the page returned will be less than or equal
+** to nearby if any such page exists.  If eMode is BTALLOC_ANY then there
+** are no restrictions on which page is returned.
 */
 static int allocateBtreePage(
-  BtShared *pBt, 
-  MemPage **ppPage, 
-  Pgno *pPgno, 
-  Pgno nearby,
-  u8 exact
+  BtShared *pBt,         /* The btree */
+  MemPage **ppPage,      /* Store pointer to the allocated page here */
+  Pgno *pPgno,           /* Store the page number here */
+  Pgno nearby,           /* Search for a page near this one */
+  u8 eMode               /* BTALLOC_EXACT, BTALLOC_LT, or BTALLOC_ANY */
 ){
   MemPage *pPage1;
   int rc;
@@ -4878,6 +4960,7 @@ static int allocateBtreePage(
   Pgno mxPage;     /* Total size of the database file */
 
   assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );
   pPage1 = pBt->pPage1;
   mxPage = btreePagecount(pBt);
   n = get4byte(&pPage1->aData[36]);
@@ -4890,21 +4973,24 @@ static int allocateBtreePage(
     Pgno iTrunk;
     u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
     
-    /* If the 'exact' parameter was true and a query of the pointer-map
+    /* If eMode==BTALLOC_EXACT and a query of the pointer-map
     ** shows that the page 'nearby' is somewhere on the free-list, then
     ** the entire-list will be searched for that page.
     */
 #ifndef SQLITE_OMIT_AUTOVACUUM
-    if( exact && nearby<=mxPage ){
-      u8 eType;
-      assert( nearby>0 );
-      assert( pBt->autoVacuum );
-      rc = ptrmapGet(pBt, nearby, &eType, 0);
-      if( rc ) return rc;
-      if( eType==PTRMAP_FREEPAGE ){
-        searchList = 1;
+    if( eMode==BTALLOC_EXACT ){
+      if( nearby<=mxPage ){
+        u8 eType;
+        assert( nearby>0 );
+        assert( pBt->autoVacuum );
+        rc = ptrmapGet(pBt, nearby, &eType, 0);
+        if( rc ) return rc;
+        if( eType==PTRMAP_FREEPAGE ){
+          searchList = 1;
+        }
       }
-      *pPgno = nearby;
+    }else if( eMode==BTALLOC_LE ){
+      searchList = 1;
     }
 #endif
 
@@ -4917,7 +5003,8 @@ static int allocateBtreePage(
 
     /* The code within this loop is run only once if the 'searchList' variable
     ** is not true. Otherwise, it runs once for each trunk-page on the
-    ** free-list until the page 'nearby' is located.
+    ** free-list until the page 'nearby' is located (eMode==BTALLOC_EXACT)
+    ** or until a page less than 'nearby' is located (eMode==BTALLOC_LT)
     */
     do {
       pPrevTrunk = pTrunk;
@@ -4930,7 +5017,7 @@ static int allocateBtreePage(
       if( iTrunk>mxPage ){
         rc = SQLITE_CORRUPT_BKPT;
       }else{
-        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0, 0);
       }
       if( rc ){
         pTrunk = 0;
@@ -4959,11 +5046,13 @@ static int allocateBtreePage(
         rc = SQLITE_CORRUPT_BKPT;
         goto end_allocate_page;
 #ifndef SQLITE_OMIT_AUTOVACUUM
-      }else if( searchList && nearby==iTrunk ){
+      }else if( searchList 
+            && (nearby==iTrunk || (iTrunk<nearby && eMode==BTALLOC_LE)) 
+      ){
         /* The list is being searched and this trunk page is the page
         ** to allocate, regardless of whether it has leaves.
         */
-        assert( *pPgno==iTrunk );
+        *pPgno = iTrunk;
         *ppPage = pTrunk;
         searchList = 0;
         rc = sqlite3PagerWrite(pTrunk->pDbPage);
@@ -4992,7 +5081,7 @@ static int allocateBtreePage(
             goto end_allocate_page;
           }
           testcase( iNewTrunk==mxPage );
-          rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
+          rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0, 0);
           if( rc!=SQLITE_OK ){
             goto end_allocate_page;
           }
@@ -5026,14 +5115,24 @@ static int allocateBtreePage(
         unsigned char *aData = pTrunk->aData;
         if( nearby>0 ){
           u32 i;
-          int dist;
           closest = 0;
-          dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);
-          for(i=1; i<k; i++){
-            int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);
-            if( d2<dist ){
-              closest = i;
-              dist = d2;
+          if( eMode==BTALLOC_LE ){
+            for(i=0; i<k; i++){
+              iPage = get4byte(&aData[8+i*4]);
+              if( iPage<=nearby ){
+                closest = i;
+                break;
+              }
+            }
+          }else{
+            int dist;
+            dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);
+            for(i=1; i<k; i++){
+              int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);
+              if( d2<dist ){
+                closest = i;
+                dist = d2;
+              }
             }
           }
         }else{
@@ -5047,7 +5146,9 @@ static int allocateBtreePage(
           goto end_allocate_page;
         }
         testcase( iPage==mxPage );
-        if( !searchList || iPage==nearby ){
+        if( !searchList 
+         || (iPage==nearby || (iPage<nearby && eMode==BTALLOC_LE)) 
+        ){
           int noContent;
           *pPgno = iPage;
           TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d"
@@ -5060,7 +5161,7 @@ static int allocateBtreePage(
           }
           put4byte(&aData[4], k-1);
           noContent = !btreeGetHasContent(pBt, *pPgno);
-          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
+          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent, 0);
           if( rc==SQLITE_OK ){
             rc = sqlite3PagerWrite((*ppPage)->pDbPage);
             if( rc!=SQLITE_OK ){
@@ -5074,8 +5175,26 @@ static int allocateBtreePage(
       pPrevTrunk = 0;
     }while( searchList );
   }else{
-    /* There are no pages on the freelist, so create a new page at the
-    ** end of the file */
+    /* There are no pages on the freelist, so append a new page to the
+    ** database image.
+    **
+    ** Normally, new pages allocated by this block can be requested from the
+    ** pager layer with the 'no-content' flag set. This prevents the pager
+    ** from trying to read the pages content from disk. However, if the
+    ** current transaction has already run one or more incremental-vacuum
+    ** steps, then the page we are about to allocate may contain content
+    ** that is required in the event of a rollback. In this case, do
+    ** not set the no-content flag. This causes the pager to load and journal
+    ** the current page content before overwriting it.
+    **
+    ** Note that the pager will not actually attempt to load or journal 
+    ** content for any page that really does lie past the end of the database
+    ** file on disk. So the effects of disabling the no-content optimization
+    ** here are confined to those pages that lie between the end of the
+    ** database image and the end of the database file.
+    */
+    int bNoContent = (0==IfNotOmitAV(pBt->bDoTruncate));
+
     rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
     if( rc ) return rc;
     pBt->nPage++;
@@ -5090,7 +5209,7 @@ static int allocateBtreePage(
       MemPage *pPg = 0;
       TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", pBt->nPage));
       assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );
-      rc = btreeGetPage(pBt, pBt->nPage, &pPg, 1);
+      rc = btreeGetPage(pBt, pBt->nPage, &pPg, bNoContent, 0);
       if( rc==SQLITE_OK ){
         rc = sqlite3PagerWrite(pPg->pDbPage);
         releasePage(pPg);
@@ -5104,7 +5223,7 @@ static int allocateBtreePage(
     *pPgno = pBt->nPage;
 
     assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
-    rc = btreeGetPage(pBt, *pPgno, ppPage, 1);
+    rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent, 0);
     if( rc ) return rc;
     rc = sqlite3PagerWrite((*ppPage)->pDbPage);
     if( rc!=SQLITE_OK ){
@@ -5172,7 +5291,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
     /* If the secure_delete option is enabled, then
     ** always fully overwrite deleted information with zeros.
     */
-    if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0))!=0) )
+    if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0, 0))!=0) )
      ||            ((rc = sqlite3PagerWrite(pPage->pDbPage))!=0)
     ){
       goto freepage_out;
@@ -5199,7 +5318,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
     u32 nLeaf;                /* Initial number of leaf cells on trunk page */
 
     iTrunk = get4byte(&pPage1->aData[32]);
-    rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+    rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0, 0);
     if( rc!=SQLITE_OK ){
       goto freepage_out;
     }
@@ -5245,7 +5364,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
   ** first trunk in the free-list is full. Either way, the page being freed
   ** will become the new first trunk page in the free-list.
   */
-  if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0)) ){
+  if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0, 0)) ){
     goto freepage_out;
   }
   rc = sqlite3PagerWrite(pPage->pDbPage);
@@ -5432,7 +5551,7 @@ static int fillInCell(
       ** If this is the first overflow page, then write a partial entry 
       ** to the pointer-map. If we write nothing to this pointer-map slot,
       ** then the optimistic overflow chain processing in clearCell()
-      ** may misinterpret the uninitialised values and delete the
+      ** may misinterpret the uninitialized values and delete the
       ** wrong pages from the database.
       */
       if( pBt->autoVacuum && rc==SQLITE_OK ){
@@ -6046,7 +6165,7 @@ static int balance_nonroot(
   }
   pgno = get4byte(pRight);
   while( 1 ){
-    rc = getAndInitPage(pBt, pgno, &apOld[i]);
+    rc = getAndInitPage(pBt, pgno, &apOld[i], 0);
     if( rc ){
       memset(apOld, 0, (i+1)*sizeof(MemPage*));
       goto balance_cleanup;
@@ -6905,7 +7024,7 @@ int sqlite3BtreeInsert(
   insertCell(pPage, idx, newCell, szNew, 0, 0, &rc);
   assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );
 
-  /* If no error has occured and pPage has an overflow cell, call balance() 
+  /* If no error has occurred and pPage has an overflow cell, call balance() 
   ** to redistribute the cells within the tree. Since balance() may move
   ** the cursor, zero the BtCursor.info.nSize and BtCursor.validNKey
   ** variables.
@@ -7119,7 +7238,7 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
     ** be moved to the allocated page (unless the allocated page happens
     ** to reside at pgnoRoot).
     */
-    rc = allocateBtreePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, 1);
+    rc = allocateBtreePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, BTALLOC_EXACT);
     if( rc!=SQLITE_OK ){
       return rc;
     }
@@ -7134,10 +7253,17 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
       u8 eType = 0;
       Pgno iPtrPage = 0;
 
+      /* Save the positions of any open cursors. This is required in
+      ** case they are holding a reference to an xFetch reference
+      ** corresponding to page pgnoRoot.  */
+      rc = saveAllCursors(pBt, 0, 0);
       releasePage(pPageMove);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
 
       /* Move the page currently at pgnoRoot to pgnoMove. */
-      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
+      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
@@ -7158,7 +7284,7 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
       if( rc!=SQLITE_OK ){
         return rc;
       }
-      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
+      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
@@ -7234,7 +7360,7 @@ static int clearDatabasePage(
     return SQLITE_CORRUPT_BKPT;
   }
 
-  rc = getAndInitPage(pBt, pgno, &pPage);
+  rc = getAndInitPage(pBt, pgno, &pPage, 0);
   if( rc ) return rc;
   for(i=0; i<pPage->nCell; i++){
     pCell = findCell(pPage, i);
@@ -7336,7 +7462,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
     return SQLITE_LOCKED_SHAREDCACHE;
   }
 
-  rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
+  rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0, 0);
   if( rc ) return rc;
   rc = sqlite3BtreeClearTable(p, iTable, 0);
   if( rc ){
@@ -7371,7 +7497,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
         */
         MemPage *pMove;
         releasePage(pPage);
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0, 0);
         if( rc!=SQLITE_OK ){
           return rc;
         }
@@ -7381,7 +7507,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
           return rc;
         }
         pMove = 0;
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0, 0);
         freePage(pMove, &rc);
         releasePage(pMove);
         if( rc!=SQLITE_OK ){
@@ -7793,7 +7919,7 @@ static int checkTreePage(
   usableSize = pBt->usableSize;
   if( iPage==0 ) return 0;
   if( checkRef(pCheck, iPage, zParentContext) ) return 0;
-  if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
+  if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0, 0))!=0 ){
     checkAppendMsg(pCheck, zContext,
        "unable to get the page. error code=%d", rc);
     return 0;
@@ -8026,7 +8152,7 @@ char *sqlite3BtreeIntegrityCheck(
   }
   i = PENDING_BYTE_PAGE(pBt);
   if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);
-  sqlite3StrAccumInit(&sCheck.errMsg, zErr, sizeof(zErr), 20000);
+  sqlite3StrAccumInit(&sCheck.errMsg, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);
   sCheck.errMsg.useMalloc = 2;
 
   /* Check the integrity of the freelist
@@ -8265,6 +8391,17 @@ int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
     return SQLITE_ABORT;
   }
 
+  /* Save the positions of all other cursors open on this table. This is
+  ** required in case any of them are holding references to an xFetch
+  ** version of the b-tree page modified by the accessPayload call below.
+  **
+  ** Note that pCsr must be open on a BTREE_INTKEY table and saveCursorPosition()
+  ** and hence saveAllCursors() cannot fail on a BTREE_INTKEY table, hence
+  ** saveAllCursors can only return SQLITE_OK.
+  */
+  VVA_ONLY(rc =) saveAllCursors(pCsr->pBt, pCsr->pgnoRoot, pCsr);
+  assert( rc==SQLITE_OK );
+
   /* Check some assumptions: 
   **   (a) the cursor is open for writing,
   **   (b) there is a read/write transaction open,
diff --git a/lib/libsqlite3/src/btree.h b/lib/libsqlite3/src/btree.h
index d4c9fe37d78..ace0f8cd217 100644
--- a/lib/libsqlite3/src/btree.h
+++ b/lib/libsqlite3/src/btree.h
@@ -63,6 +63,7 @@ int sqlite3BtreeOpen(
 
 int sqlite3BtreeClose(Btree*);
 int sqlite3BtreeSetCacheSize(Btree*,int);
+int sqlite3BtreeSetMmapLimit(Btree*,sqlite3_int64);
 int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int);
 int sqlite3BtreeSyncDisabled(Btree*);
 int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
@@ -139,6 +140,7 @@ int sqlite3BtreeNewDb(Btree *p);
 #define BTREE_TEXT_ENCODING       5
 #define BTREE_USER_VERSION        6
 #define BTREE_INCR_VACUUM         7
+#define BTREE_APPLICATION_ID      8
 
 /*
 ** Values that may be OR'd together to form the second argument of an
diff --git a/lib/libsqlite3/src/btreeInt.h b/lib/libsqlite3/src/btreeInt.h
index b157decec79..ce3c5493f8c 100644
--- a/lib/libsqlite3/src/btreeInt.h
+++ b/lib/libsqlite3/src/btreeInt.h
@@ -411,6 +411,7 @@ struct BtShared {
 #ifndef SQLITE_OMIT_AUTOVACUUM
   u8 autoVacuum;        /* True if auto-vacuum is enabled */
   u8 incrVacuum;        /* True if incr-vacuum is enabled */
+  u8 bDoTruncate;       /* True to truncate db on commit */
 #endif
   u8 inTransaction;     /* Transaction state */
   u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */
diff --git a/lib/libsqlite3/src/build.c b/lib/libsqlite3/src/build.c
index c21f0172a9b..3c91cdcfdb7 100644
--- a/lib/libsqlite3/src/build.c
+++ b/lib/libsqlite3/src/build.c
@@ -2100,7 +2100,7 @@ void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, int isView){
   /* Drop all SQLITE_MASTER table and index entries that refer to the
   ** table. The program name loops through the master table and deletes
   ** every row that refers to a table of the same name as the one being
-  ** dropped. Triggers are handled seperately because a trigger can be
+  ** dropped. Triggers are handled separately because a trigger can be
   ** created in the temp database that refers to a table in another
   ** database.
   */
@@ -2392,9 +2392,6 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   int tnum;                      /* Root page of index */
   Vdbe *v;                       /* Generate code into this virtual machine */
   KeyInfo *pKey;                 /* KeyInfo for index */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  int regIdxKey;                 /* Registers containing the index key */
-#endif
   int regRecord;                 /* Register holding assemblied index record */
   sqlite3 *db = pParse->db;      /* The database connection */
   int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
@@ -2422,13 +2419,9 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
                     (char *)pKey, P4_KEYINFO_HANDOFF);
   sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR|((memRootPage>=0)?OPFLAG_P2ISREG:0));
 
-#ifndef SQLITE_OMIT_MERGE_SORT
   /* Open the sorter cursor if we are to use one. */
   iSorter = pParse->nTab++;
   sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, 0, (char*)pKey, P4_KEYINFO);
-#else
-  iSorter = iTab;
-#endif
 
   /* Open the table. Loop through all rows of the table, inserting index
   ** records into the sorter. */
@@ -2436,7 +2429,6 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
   regRecord = sqlite3GetTempReg(pParse);
 
-#ifndef SQLITE_OMIT_MERGE_SORT
   sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
   sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
   sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
@@ -2447,8 +2439,8 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
     sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
     addr2 = sqlite3VdbeCurrentAddr(v);
     sqlite3VdbeAddOp3(v, OP_SorterCompare, iSorter, j2, regRecord);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC
+    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_UNIQUE,
+        OE_Abort, "indexed columns are not unique", P4_STATIC
     );
   }else{
     addr2 = sqlite3VdbeCurrentAddr(v);
@@ -2456,30 +2448,6 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   sqlite3VdbeAddOp2(v, OP_SorterData, iSorter, regRecord);
   sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 1);
   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-#else
-  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
-  addr2 = addr1 + 1;
-  if( pIndex->onError!=OE_None ){
-    const int regRowid = regIdxKey + pIndex->nColumn;
-    const int j2 = sqlite3VdbeCurrentAddr(v) + 2;
-    void * const pRegKey = SQLITE_INT_TO_PTR(regIdxKey);
-
-    /* The registers accessed by the OP_IsUnique opcode were allocated
-    ** using sqlite3GetTempRange() inside of the sqlite3GenerateIndexKey()
-    ** call above. Just before that function was freed they were released
-    ** (made available to the compiler for reuse) using 
-    ** sqlite3ReleaseTempRange(). So in some ways having the OP_IsUnique
-    ** opcode use the values stored within seems dangerous. However, since
-    ** we can be sure that no other temp registers have been allocated
-    ** since sqlite3ReleaseTempRange() was called, it is safe to do so.
-    */
-    sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx, j2, regRowid, pRegKey, P4_INT32);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC);
-  }
-  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 0);
-  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-#endif
   sqlite3ReleaseTempReg(pParse, regRecord);
   sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2);
   sqlite3VdbeJumpHere(v, addr1);
@@ -2594,7 +2562,7 @@ Index *sqlite3CreateIndex(
   assert( pTab!=0 );
   assert( pParse->nErr==0 );
   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
-       && memcmp(&pTab->zName[7],"altertab_",9)!=0 ){
+       && sqlite3StrNICmp(&pTab->zName[7],"altertab_",9)!=0 ){
     sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
     goto exit_create_index;
   }
@@ -2691,10 +2659,8 @@ Index *sqlite3CreateIndex(
   for(i=0; i<pList->nExpr; i++){
     Expr *pExpr = pList->a[i].pExpr;
     if( pExpr ){
-      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr);
-      if( pColl ){
-        nExtra += (1 + sqlite3Strlen30(pColl->zName));
-      }
+      assert( pExpr->op==TK_COLLATE );
+      nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));
     }
   }
 
@@ -2755,7 +2721,6 @@ Index *sqlite3CreateIndex(
     const char *zColName = pListItem->zName;
     Column *pTabCol;
     int requestedSortOrder;
-    CollSeq *pColl;                /* Collating sequence */
     char *zColl;                   /* Collation sequence name */
 
     for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
@@ -2768,11 +2733,10 @@ Index *sqlite3CreateIndex(
       goto exit_create_index;
     }
     pIndex->aiColumn[i] = j;
-    if( pListItem->pExpr
-     && (pColl = sqlite3ExprCollSeq(pParse, pListItem->pExpr))!=0
-    ){
+    if( pListItem->pExpr ){
       int nColl;
-      zColl = pColl->zName;
+      assert( pListItem->pExpr->op==TK_COLLATE );
+      zColl = pListItem->pExpr->u.zToken;
       nColl = sqlite3Strlen30(zColl) + 1;
       assert( nExtra>=nColl );
       memcpy(zExtra, zColl, nColl);
@@ -2781,9 +2745,7 @@ Index *sqlite3CreateIndex(
       nExtra -= nColl;
     }else{
       zColl = pTab->aCol[j].zColl;
-      if( !zColl ){
-        zColl = "BINARY";
-      }
+      if( !zColl ) zColl = "BINARY";
     }
     if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){
       goto exit_create_index;
@@ -2839,7 +2801,7 @@ Index *sqlite3CreateIndex(
           ** However the ON CONFLICT clauses are different. If both this 
           ** constraint and the previous equivalent constraint have explicit
           ** ON CONFLICT clauses this is an error. Otherwise, use the
-          ** explicitly specified behaviour for the index.
+          ** explicitly specified behavior for the index.
           */
           if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){
             sqlite3ErrorMsg(pParse, 
@@ -3692,12 +3654,19 @@ void sqlite3MayAbort(Parse *pParse){
 ** error. The onError parameter determines which (if any) of the statement
 ** and/or current transaction is rolled back.
 */
-void sqlite3HaltConstraint(Parse *pParse, int onError, char *p4, int p4type){
+void sqlite3HaltConstraint(
+  Parse *pParse,    /* Parsing context */
+  int errCode,      /* extended error code */
+  int onError,      /* Constraint type */
+  char *p4,         /* Error message */
+  int p4type        /* P4_STATIC or P4_TRANSIENT */
+){
   Vdbe *v = sqlite3GetVdbe(pParse);
+  assert( (errCode&0xff)==SQLITE_CONSTRAINT );
   if( onError==OE_Abort ){
     sqlite3MayAbort(pParse);
   }
-  sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0, p4, p4type);
+  sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
 }
 
 /*
diff --git a/lib/libsqlite3/src/ctime.c b/lib/libsqlite3/src/ctime.c
index 5dee7247478..60595ff88d9 100644
--- a/lib/libsqlite3/src/ctime.c
+++ b/lib/libsqlite3/src/ctime.c
@@ -48,15 +48,15 @@ static const char * const azCompileOpt[] = {
 #ifdef SQLITE_COVERAGE_TEST
   "COVERAGE_TEST",
 #endif
-#ifdef SQLITE_CURDIR
-  "CURDIR",
-#endif
 #ifdef SQLITE_DEBUG
   "DEBUG",
 #endif
 #ifdef SQLITE_DEFAULT_LOCKING_MODE
   "DEFAULT_LOCKING_MODE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOCKING_MODE),
 #endif
+#if defined(SQLITE_DEFAULT_MMAP_SIZE) && !defined(SQLITE_DEFAULT_MMAP_SIZE_xc)
+  "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),
+#endif
 #ifdef SQLITE_DISABLE_DIRSYNC
   "DISABLE_DIRSYNC",
 #endif
@@ -147,6 +147,9 @@ static const char * const azCompileOpt[] = {
 #ifdef SQLITE_LOCK_TRACE
   "LOCK_TRACE",
 #endif
+#if defined(SQLITE_MAX_MMAP_SIZE) && !defined(SQLITE_MAX_MMAP_SIZE_xc)
+  "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE),
+#endif
 #ifdef SQLITE_MAX_SCHEMA_RETRY
   "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),
 #endif
@@ -204,11 +207,6 @@ static const char * const azCompileOpt[] = {
 #ifdef SQLITE_OMIT_CHECK
   "OMIT_CHECK",
 #endif
-/* // redundant
-** #ifdef SQLITE_OMIT_COMPILEOPTION_DIAGS
-**   "OMIT_COMPILEOPTION_DIAGS",
-** #endif
-*/
 #ifdef SQLITE_OMIT_COMPLETE
   "OMIT_COMPLETE",
 #endif
@@ -263,9 +261,6 @@ static const char * const azCompileOpt[] = {
 #ifdef SQLITE_OMIT_MEMORYDB
   "OMIT_MEMORYDB",
 #endif
-#ifdef SQLITE_OMIT_MERGE_SORT
-  "OMIT_MERGE_SORT",
-#endif
 #ifdef SQLITE_OMIT_OR_OPTIMIZATION
   "OMIT_OR_OPTIMIZATION",
 #endif
@@ -353,13 +348,13 @@ static const char * const azCompileOpt[] = {
 #ifdef SQLITE_TCL
   "TCL",
 #endif
-#ifdef SQLITE_TEMP_STORE
+#if defined(SQLITE_TEMP_STORE) && !defined(SQLITE_TEMP_STORE_xc)
   "TEMP_STORE=" CTIMEOPT_VAL(SQLITE_TEMP_STORE),
 #endif
 #ifdef SQLITE_TEST
   "TEST",
 #endif
-#ifdef SQLITE_THREADSAFE
+#if defined(SQLITE_THREADSAFE)
   "THREADSAFE=" CTIMEOPT_VAL(SQLITE_THREADSAFE),
 #endif
 #ifdef SQLITE_USE_ALLOCA
@@ -385,8 +380,11 @@ int sqlite3_compileoption_used(const char *zOptName){
   /* Since ArraySize(azCompileOpt) is normally in single digits, a
   ** linear search is adequate.  No need for a binary search. */
   for(i=0; i<ArraySize(azCompileOpt); i++){
-    if(   (sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0)
-       && ( (azCompileOpt[i][n]==0) || (azCompileOpt[i][n]=='=') ) ) return 1;
+    if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
+     && sqlite3CtypeMap[(unsigned char)azCompileOpt[i][n]]==0
+    ){
+      return 1;
+    }
   }
   return 0;
 }
diff --git a/lib/libsqlite3/src/delete.c b/lib/libsqlite3/src/delete.c
index 01a130d65b4..634e115563a 100644
--- a/lib/libsqlite3/src/delete.c
+++ b/lib/libsqlite3/src/delete.c
@@ -93,30 +93,28 @@ void sqlite3MaterializeView(
   int iCur             /* Cursor number for ephemerial table */
 ){
   SelectDest dest;
-  Select *pDup;
+  Select *pSel;
+  SrcList *pFrom;
   sqlite3 *db = pParse->db;
+  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
 
-  pDup = sqlite3SelectDup(db, pView->pSelect, 0);
-  if( pWhere ){
-    SrcList *pFrom;
-    
-    pWhere = sqlite3ExprDup(db, pWhere, 0);
-    pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
-    if( pFrom ){
-      assert( pFrom->nSrc==1 );
-      pFrom->a[0].zAlias = sqlite3DbStrDup(db, pView->zName);
-      pFrom->a[0].pSelect = pDup;
-      assert( pFrom->a[0].pOn==0 );
-      assert( pFrom->a[0].pUsing==0 );
-    }else{
-      sqlite3SelectDelete(db, pDup);
-    }
-    pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
-    if( pDup ) pDup->selFlags |= SF_Materialize;
+  pWhere = sqlite3ExprDup(db, pWhere, 0);
+  pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
+
+  if( pFrom ){
+    assert( pFrom->nSrc==1 );
+    pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
+    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
+    assert( pFrom->a[0].pOn==0 );
+    assert( pFrom->a[0].pUsing==0 );
   }
+
+  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
+  if( pSel ) pSel->selFlags |= SF_Materialize;
+
   sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
-  sqlite3Select(pParse, pDup, &dest);
-  sqlite3SelectDelete(db, pDup);
+  sqlite3Select(pParse, pSel, &dest);
+  sqlite3SelectDelete(db, pSel);
 }
 #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
 
diff --git a/lib/libsqlite3/src/expr.c b/lib/libsqlite3/src/expr.c
index 9ca34ec7b7f..660397e078a 100644
--- a/lib/libsqlite3/src/expr.c
+++ b/lib/libsqlite3/src/expr.c
@@ -116,12 +116,7 @@ CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
     }
     assert( op!=TK_REGISTER || p->op2!=TK_COLLATE );
     if( op==TK_COLLATE ){
-      if( db->init.busy ){
-        /* Do not report errors when parsing while the schema */
-        pColl = sqlite3FindCollSeq(db, ENC(db), p->u.zToken, 0);
-      }else{
-        pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
-      }
+      pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
       break;
     }
     if( p->pTab!=0
@@ -638,7 +633,7 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
       */
       ynVar i;
       for(i=0; i<pParse->nzVar; i++){
-        if( pParse->azVar[i] && memcmp(pParse->azVar[i],z,n+1)==0 ){
+        if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
           pExpr->iColumn = x = (ynVar)i+1;
           break;
         }
@@ -1214,6 +1209,7 @@ static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
 }
 static int exprIsConst(Expr *p, int initFlag){
   Walker w;
+  memset(&w, 0, sizeof(w));
   w.u.i = initFlag;
   w.xExprCallback = exprNodeIsConstant;
   w.xSelectCallback = selectNodeIsConstant;
@@ -1456,10 +1452,11 @@ int sqlite3CodeOnce(Parse *pParse){
 **
 ** The returned value of this function indicates the b-tree type, as follows:
 **
-**   IN_INDEX_ROWID - The cursor was opened on a database table.
-**   IN_INDEX_INDEX - The cursor was opened on a database index.
-**   IN_INDEX_EPH -   The cursor was opened on a specially created and
-**                    populated epheremal table.
+**   IN_INDEX_ROWID      - The cursor was opened on a database table.
+**   IN_INDEX_INDEX_ASC  - The cursor was opened on an ascending index.
+**   IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
+**   IN_INDEX_EPH        - The cursor was opened on a specially created and
+**                         populated epheremal table.
 **
 ** An existing b-tree might be used if the RHS expression pX is a simple
 ** subquery such as:
@@ -1582,7 +1579,8 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
           sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                                pKey,P4_KEYINFO_HANDOFF);
           VdbeComment((v, "%s", pIdx->zName));
-          eType = IN_INDEX_INDEX;
+          assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
+          eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
 
           sqlite3VdbeJumpHere(v, iAddr);
           if( prNotFound && !pTab->aCol[iCol].notNull ){
@@ -2935,7 +2933,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
         sqlite3VdbeAddOp4(
             v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
       }else{
-        sqlite3HaltConstraint(pParse, pExpr->affinity, pExpr->u.zToken, 0);
+        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,
+                              pExpr->affinity, pExpr->u.zToken, 0);
       }
 
       break;
@@ -3281,6 +3280,12 @@ void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
       sqlite3ExplainPush(pOut);
       sqlite3ExplainExpr(pOut, pList->a[i].pExpr);
       sqlite3ExplainPop(pOut);
+      if( pList->a[i].zName ){
+        sqlite3ExplainPrintf(pOut, " AS %s", pList->a[i].zName);
+      }
+      if( pList->a[i].bSpanIsTab ){
+        sqlite3ExplainPrintf(pOut, " (%s)", pList->a[i].zSpan);
+      }
       if( i<pList->nExpr-1 ){
         sqlite3ExplainNL(pOut);
       }
@@ -3419,8 +3424,8 @@ void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
   Walker w;
   if( pParse->cookieGoto ) return;
   if( OptimizationDisabled(pParse->db, SQLITE_FactorOutConst) ) return;
+  memset(&w, 0, sizeof(w));
   w.xExprCallback = evalConstExpr;
-  w.xSelectCallback = 0;
   w.pParse = pParse;
   sqlite3WalkExpr(&w, pExpr);
 }
@@ -3533,7 +3538,7 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
   int r1, r2;
 
   assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
-  if( NEVER(v==0) )     return;  /* Existance of VDBE checked by caller */
+  if( NEVER(v==0) )     return;  /* Existence of VDBE checked by caller */
   if( NEVER(pExpr==0) ) return;  /* No way this can happen */
   op = pExpr->op;
   switch( op ){
@@ -3653,7 +3658,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
   int r1, r2;
 
   assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
-  if( NEVER(v==0) ) return; /* Existance of VDBE checked by caller */
+  if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
   if( pExpr==0 )    return;
 
   /* The value of pExpr->op and op are related as follows:
diff --git a/lib/libsqlite3/src/fkey.c b/lib/libsqlite3/src/fkey.c
index 2d01e2524b3..ac35bc194cd 100644
--- a/lib/libsqlite3/src/fkey.c
+++ b/lib/libsqlite3/src/fkey.c
@@ -21,8 +21,9 @@
 ** --------------------------
 **
 ** Foreign keys in SQLite come in two flavours: deferred and immediate.
-** If an immediate foreign key constraint is violated, SQLITE_CONSTRAINT
-** is returned and the current statement transaction rolled back. If a 
+** If an immediate foreign key constraint is violated,
+** SQLITE_CONSTRAINT_FOREIGNKEY is returned and the current
+** statement transaction rolled back. If a 
 ** deferred foreign key constraint is violated, no action is taken 
 ** immediately. However if the application attempts to commit the 
 ** transaction before fixing the constraint violation, the attempt fails.
@@ -86,7 +87,8 @@
 ** Immediate constraints are usually handled similarly. The only difference 
 ** is that the counter used is stored as part of each individual statement
 ** object (struct Vdbe). If, after the statement has run, its immediate
-** constraint counter is greater than zero, it returns SQLITE_CONSTRAINT
+** constraint counter is greater than zero,
+** it returns SQLITE_CONSTRAINT_FOREIGNKEY
 ** and the statement transaction is rolled back. An exception is an INSERT
 ** statement that inserts a single row only (no triggers). In this case,
 ** instead of using a counter, an exception is thrown immediately if the
@@ -142,7 +144,7 @@
 ** A foreign key constraint requires that the key columns in the parent
 ** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.
 ** Given that pParent is the parent table for foreign key constraint pFKey, 
-** search the schema a unique index on the parent key columns. 
+** search the schema for a unique index on the parent key columns. 
 **
 ** If successful, zero is returned. If the parent key is an INTEGER PRIMARY 
 ** KEY column, then output variable *ppIdx is set to NULL. Otherwise, *ppIdx 
@@ -178,7 +180,7 @@
 ** into pParse. If an OOM error occurs, non-zero is returned and the
 ** pParse->db->mallocFailed flag is set.
 */
-static int locateFkeyIndex(
+int sqlite3FkLocateIndex(
   Parse *pParse,                  /* Parse context to store any error in */
   Table *pParent,                 /* Parent table of FK constraint pFKey */
   FKey *pFKey,                    /* Foreign key to find index for */
@@ -275,7 +277,9 @@ static int locateFkeyIndex(
 
   if( !pIdx ){
     if( !pParse->disableTriggers ){
-      sqlite3ErrorMsg(pParse, "foreign key mismatch");
+      sqlite3ErrorMsg(pParse,
+           "foreign key mismatch - \"%w\" referencing \"%w\"",
+           pFKey->pFrom->zName, pFKey->zTo);
     }
     sqlite3DbFree(pParse->db, aiCol);
     return 1;
@@ -424,8 +428,8 @@ static void fkLookupParent(
     ** incrementing a counter. This is necessary as the VM code is being
     ** generated for will not open a statement transaction.  */
     assert( nIncr==1 );
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
+    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
+        OE_Abort, "foreign key constraint failed", P4_STATIC
     );
   }else{
     if( nIncr>0 && pFKey->isDeferred==0 ){
@@ -665,8 +669,8 @@ void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTab){
     ** any modifications to the schema are made. This is because statement
     ** transactions are not able to rollback schema changes.  */
     sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
+    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
+        OE_Abort, "foreign key constraint failed", P4_STATIC
     );
 
     if( iSkip ){
@@ -736,7 +740,7 @@ void sqlite3FkCheck(
     }else{
       pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);
     }
-    if( !pTo || locateFkeyIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
+    if( !pTo || sqlite3FkLocateIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
       assert( isIgnoreErrors==0 || (regOld!=0 && regNew==0) );
       if( !isIgnoreErrors || db->mallocFailed ) return;
       if( pTo==0 ){
@@ -816,7 +820,7 @@ void sqlite3FkCheck(
       continue;
     }
 
-    if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
+    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
       if( !isIgnoreErrors || db->mallocFailed ) return;
       continue;
     }
@@ -871,7 +875,7 @@ u32 sqlite3FkOldmask(
     }
     for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
       Index *pIdx = 0;
-      locateFkeyIndex(pParse, pTab, p, &pIdx, 0);
+      sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
       if( pIdx ){
         for(i=0; i<pIdx->nColumn; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);
       }
@@ -997,7 +1001,7 @@ static Trigger *fkActionTrigger(
     int i;                        /* Iterator variable */
     Expr *pWhen = 0;              /* WHEN clause for the trigger */
 
-    if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
+    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
     assert( aiCol || pFKey->nCol==1 );
 
     for(i=0; i<pFKey->nCol; i++){
diff --git a/lib/libsqlite3/src/func.c b/lib/libsqlite3/src/func.c
index d4655ad7e96..e40fdad55a8 100644
--- a/lib/libsqlite3/src/func.c
+++ b/lib/libsqlite3/src/func.c
@@ -694,6 +694,13 @@ static int patternCompare(
 }
 
 /*
+** The sqlite3_strglob() interface.
+*/
+int sqlite3_strglob(const char *zGlobPattern, const char *zString){
+  return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, 0)==0;
+}
+
+/*
 ** Count the number of times that the LIKE operator (or GLOB which is
 ** just a variation of LIKE) gets called.  This is used for testing
 ** only.
@@ -963,6 +970,62 @@ static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 }
 
 /*
+** The unicode() function.  Return the integer unicode code-point value
+** for the first character of the input string. 
+*/
+static void unicodeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *z = sqlite3_value_text(argv[0]);
+  (void)argc;
+  if( z && z[0] ) sqlite3_result_int(context, sqlite3Utf8Read(&z));
+}
+
+/*
+** The char() function takes zero or more arguments, each of which is
+** an integer.  It constructs a string where each character of the string
+** is the unicode character for the corresponding integer argument.
+*/
+static void charFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  unsigned char *z, *zOut;
+  int i;
+  zOut = z = sqlite3_malloc( argc*4 );
+  if( z==0 ){
+    sqlite3_result_error_nomem(context);
+    return;
+  }
+  for(i=0; i<argc; i++){
+    sqlite3_int64 x;
+    unsigned c;
+    x = sqlite3_value_int64(argv[i]);
+    if( x<0 || x>0x10ffff ) x = 0xfffd;
+    c = (unsigned)(x & 0x1fffff);
+    if( c<0x00080 ){
+      *zOut++ = (u8)(c&0xFF);
+    }else if( c<0x00800 ){
+      *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);
+      *zOut++ = 0x80 + (u8)(c & 0x3F);
+    }else if( c<0x10000 ){
+      *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);
+      *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
+      *zOut++ = 0x80 + (u8)(c & 0x3F);
+    }else{
+      *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);
+      *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);
+      *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
+      *zOut++ = 0x80 + (u8)(c & 0x3F);
+    }                                                    \
+  }
+  sqlite3_result_text(context, (char*)z, (int)(zOut-z), sqlite3_free);
+}
+
+/*
 ** The hex() function.  Interpret the argument as a blob.  Return
 ** a hexadecimal rendering as text.
 */
@@ -1589,6 +1652,8 @@ void sqlite3RegisterGlobalFunctions(void){
     FUNCTION(instr,              2, 0, 0, instrFunc        ),
     FUNCTION(substr,             2, 0, 0, substrFunc       ),
     FUNCTION(substr,             3, 0, 0, substrFunc       ),
+    FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),
+    FUNCTION(char,              -1, 0, 0, charFunc         ),
     FUNCTION(abs,                1, 0, 0, absFunc          ),
 #ifndef SQLITE_OMIT_FLOATING_POINT
     FUNCTION(round,              1, 0, 0, roundFunc        ),
diff --git a/lib/libsqlite3/src/global.c b/lib/libsqlite3/src/global.c
index f5da7e7f1f4..7b02cf2130e 100644
--- a/lib/libsqlite3/src/global.c
+++ b/lib/libsqlite3/src/global.c
@@ -156,6 +156,8 @@ SQLITE_WSD struct Sqlite3Config sqlite3Config = {
    (void*)0,                  /* pHeap */
    0,                         /* nHeap */
    0, 0,                      /* mnHeap, mxHeap */
+   SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */
+   SQLITE_MAX_MMAP_SIZE,      /* mxMmap */
    (void*)0,                  /* pScratch */
    0,                         /* szScratch */
    0,                         /* nScratch */
diff --git a/lib/libsqlite3/src/hash.h b/lib/libsqlite3/src/hash.h
index 990a2d6e22d..82b7c58c710 100644
--- a/lib/libsqlite3/src/hash.h
+++ b/lib/libsqlite3/src/hash.h
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.
 */
 #ifndef _SQLITE_HASH_H_
diff --git a/lib/libsqlite3/src/insert.c b/lib/libsqlite3/src/insert.c
index 89a5dc8a13e..9a5661f59a7 100644
--- a/lib/libsqlite3/src/insert.c
+++ b/lib/libsqlite3/src/insert.c
@@ -1245,7 +1245,7 @@ void sqlite3GenerateConstraintChecks(
       case OE_Fail: {
         char *zMsg;
         sqlite3VdbeAddOp3(v, OP_HaltIfNull,
-                                  SQLITE_CONSTRAINT, onError, regData+i);
+                          SQLITE_CONSTRAINT_NOTNULL, onError, regData+i);
         zMsg = sqlite3MPrintf(db, "%s.%s may not be NULL",
                               pTab->zName, pTab->aCol[i].zName);
         sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
@@ -1285,7 +1285,8 @@ void sqlite3GenerateConstraintChecks(
         }else{
           zConsName = 0;
         }
-        sqlite3HaltConstraint(pParse, onError, zConsName, P4_DYNAMIC);
+        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
+                              onError, zConsName, P4_DYNAMIC);
       }
       sqlite3VdbeResolveLabel(v, allOk);
     }
@@ -1316,8 +1317,8 @@ void sqlite3GenerateConstraintChecks(
       case OE_Rollback:
       case OE_Abort:
       case OE_Fail: {
-        sqlite3HaltConstraint(
-          pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
+        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_PRIMARYKEY,
+           onError, "PRIMARY KEY must be unique", P4_STATIC);
         break;
       }
       case OE_Replace: {
@@ -1444,7 +1445,8 @@ void sqlite3GenerateConstraintChecks(
         sqlite3StrAccumAppend(&errMsg,
             pIdx->nColumn>1 ? " are not unique" : " is not unique", -1);
         zErr = sqlite3StrAccumFinish(&errMsg);
-        sqlite3HaltConstraint(pParse, onError, zErr, 0);
+        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_UNIQUE,
+                              onError, zErr, 0);
         sqlite3DbFree(errMsg.db, zErr);
         break;
       }
@@ -1852,8 +1854,8 @@ static int xferOptimization(
   if( pDest->iPKey>=0 ){
     addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
     addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
-    sqlite3HaltConstraint(
-        pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
+    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_PRIMARYKEY,
+        onError, "PRIMARY KEY must be unique", P4_STATIC);
     sqlite3VdbeJumpHere(v, addr2);
     autoIncStep(pParse, regAutoinc, regRowid);
   }else if( pDest->pIndex==0 ){
diff --git a/lib/libsqlite3/src/journal.c b/lib/libsqlite3/src/journal.c
index 06605cc9566..fed27be3e38 100644
--- a/lib/libsqlite3/src/journal.c
+++ b/lib/libsqlite3/src/journal.c
@@ -59,6 +59,14 @@ static int createFile(JournalFile *p){
         assert(p->iSize<=p->nBuf);
         rc = sqlite3OsWrite(p->pReal, p->zBuf, p->iSize, 0);
       }
+      if( rc!=SQLITE_OK ){
+        /* If an error occurred while writing to the file, close it before
+        ** returning. This way, SQLite uses the in-memory journal data to 
+        ** roll back changes made to the internal page-cache before this
+        ** function was called.  */
+        sqlite3OsClose(pReal);
+        p->pReal = 0;
+      }
     }
   }
   return rc;
diff --git a/lib/libsqlite3/src/legacy.c b/lib/libsqlite3/src/legacy.c
index ebab2de37d9..94649ae705a 100644
--- a/lib/libsqlite3/src/legacy.c
+++ b/lib/libsqlite3/src/legacy.c
@@ -38,7 +38,6 @@ int sqlite3_exec(
   const char *zLeftover;      /* Tail of unprocessed SQL */
   sqlite3_stmt *pStmt = 0;    /* The current SQL statement */
   char **azCols = 0;          /* Names of result columns */
-  int nRetry = 0;             /* Number of retry attempts */
   int callbackIsInit;         /* True if callback data is initialized */
 
   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
@@ -46,12 +45,12 @@ int sqlite3_exec(
 
   sqlite3_mutex_enter(db->mutex);
   sqlite3Error(db, SQLITE_OK, 0);
-  while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){
+  while( rc==SQLITE_OK && zSql[0] ){
     int nCol;
     char **azVals = 0;
 
     pStmt = 0;
-    rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);
+    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
     assert( rc==SQLITE_OK || pStmt==0 );
     if( rc!=SQLITE_OK ){
       continue;
@@ -108,11 +107,8 @@ int sqlite3_exec(
       if( rc!=SQLITE_ROW ){
         rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
         pStmt = 0;
-        if( rc!=SQLITE_SCHEMA ){
-          nRetry = 0;
-          zSql = zLeftover;
-          while( sqlite3Isspace(zSql[0]) ) zSql++;
-        }
+        zSql = zLeftover;
+        while( sqlite3Isspace(zSql[0]) ) zSql++;
         break;
       }
     }
diff --git a/lib/libsqlite3/src/main.c b/lib/libsqlite3/src/main.c
index b52d4744431..39f60421e68 100644
--- a/lib/libsqlite3/src/main.c
+++ b/lib/libsqlite3/src/main.c
@@ -496,6 +496,19 @@ int sqlite3_config(int op, ...){
     }
 #endif
 
+    case SQLITE_CONFIG_MMAP_SIZE: {
+      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
+      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
+      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
+        mxMmap = SQLITE_MAX_MMAP_SIZE;
+      }
+      sqlite3GlobalConfig.mxMmap = mxMmap;
+      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
+      if( szMmap>mxMmap) szMmap = mxMmap;
+      sqlite3GlobalConfig.szMmap = szMmap;
+      break;
+    }
+
     default: {
       rc = SQLITE_ERROR;
       break;
@@ -885,10 +898,16 @@ void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
 
   /* If we reach this point, it means that the database connection has
   ** closed all sqlite3_stmt and sqlite3_backup objects and has been
-  ** pased to sqlite3_close (meaning that it is a zombie).  Therefore,
+  ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
   ** go ahead and free all resources.
   */
 
+  /* If a transaction is open, roll it back. This also ensures that if
+  ** any database schemas have been modified by an uncommitted transaction
+  ** they are reset. And that the required b-tree mutex is held to make
+  ** the pager rollback and schema reset an atomic operation. */
+  sqlite3RollbackAll(db, SQLITE_OK);
+
   /* Free any outstanding Savepoint structures. */
   sqlite3CloseSavepoints(db);
 
@@ -989,6 +1008,15 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
   int inTrans = 0;
   assert( sqlite3_mutex_held(db->mutex) );
   sqlite3BeginBenignMalloc();
+
+  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
+  ** This is important in case the transaction being rolled back has
+  ** modified the database schema. If the b-tree mutexes are not taken
+  ** here, then another shared-cache connection might sneak in between
+  ** the database rollback and schema reset, which can cause false
+  ** corruption reports in some cases.  */
+  sqlite3BtreeEnterAll(db);
+
   for(i=0; i<db->nDb; i++){
     Btree *p = db->aDb[i].pBt;
     if( p ){
@@ -1002,10 +1030,11 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
   sqlite3VtabRollback(db);
   sqlite3EndBenignMalloc();
 
-  if( db->flags&SQLITE_InternChanges ){
+  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
     sqlite3ExpirePreparedStatements(db);
     sqlite3ResetAllSchemasOfConnection(db);
   }
+  sqlite3BtreeLeaveAll(db);
 
   /* Any deferred constraint violations have now been resolved. */
   db->nDeferredCons = 0;
@@ -1017,6 +1046,110 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
 }
 
 /*
+** Return a static string containing the name corresponding to the error code
+** specified in the argument.
+*/
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) || \
+    defined(SQLITE_DEBUG_OS_TRACE)
+const char *sqlite3ErrName(int rc){
+  const char *zName = 0;
+  int i, origRc = rc;
+  for(i=0; i<2 && zName==0; i++, rc &= 0xff){
+    switch( rc ){
+      case SQLITE_OK:                 zName = "SQLITE_OK";                break;
+      case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
+      case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
+      case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
+      case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
+      case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
+      case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
+      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
+      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
+      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
+      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
+      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
+      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
+      case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
+      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
+      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
+      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
+      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
+      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
+      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
+      case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
+      case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
+      case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
+      case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
+      case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
+      case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
+      case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
+      case SQLITE_IOERR_BLOCKED:      zName = "SQLITE_IOERR_BLOCKED";     break;
+      case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
+      case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
+      case SQLITE_IOERR_CHECKRESERVEDLOCK:
+                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
+      case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
+      case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
+      case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
+      case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
+      case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
+      case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
+      case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
+      case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
+      case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
+      case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
+      case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
+      case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
+      case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
+      case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
+      case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
+      case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
+      case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
+      case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
+      case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
+      case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
+      case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
+      case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
+      case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
+      case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
+      case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
+      case SQLITE_CONSTRAINT_FOREIGNKEY:
+                                zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
+      case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
+      case SQLITE_CONSTRAINT_PRIMARYKEY:
+                                zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
+      case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
+      case SQLITE_CONSTRAINT_COMMITHOOK:
+                                zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
+      case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
+      case SQLITE_CONSTRAINT_FUNCTION:
+                                zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
+      case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
+      case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
+      case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
+      case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
+      case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
+      case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
+      case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
+      case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
+      case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
+      case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
+      case SQLITE_NOTICE_RECOVER_ROLLBACK:
+                                zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
+      case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
+      case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
+    }
+  }
+  if( zName==0 ){
+    static char zBuf[50];
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
+    zName = zBuf;
+  }
+  return zName;
+}
+#endif
+
+/*
 ** Return a static string that describes the kind of error specified in the
 ** argument.
 */
@@ -2316,6 +2449,7 @@ static int openDatabase(
   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
   db->autoCommit = 1;
   db->nextAutovac = -1;
+  db->szMmap = sqlite3GlobalConfig.szMmap;
   db->nextPagesize = 0;
   db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger
 #if SQLITE_DEFAULT_FILE_FORMAT<4
diff --git a/lib/libsqlite3/src/memjournal.c b/lib/libsqlite3/src/memjournal.c
index 3e66e215b2a..05725948f65 100644
--- a/lib/libsqlite3/src/memjournal.c
+++ b/lib/libsqlite3/src/memjournal.c
@@ -230,7 +230,9 @@ static const struct sqlite3_io_methods MemJournalMethods = {
   0,                /* xShmMap */
   0,                /* xShmLock */
   0,                /* xShmBarrier */
-  0                 /* xShmUnlock */
+  0,                /* xShmUnmap */
+  0,                /* xFetch */
+  0                 /* xUnfetch */
 };
 
 /* 
diff --git a/lib/libsqlite3/src/os.c b/lib/libsqlite3/src/os.c
index b5e918a7272..be2ea4cfc01 100644
--- a/lib/libsqlite3/src/os.c
+++ b/lib/libsqlite3/src/os.c
@@ -141,6 +141,26 @@ int sqlite3OsShmMap(
   return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/* The real implementation of xFetch and xUnfetch */
+int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
+  DO_OS_MALLOC_TEST(id);
+  return id->pMethods->xFetch(id, iOff, iAmt, pp);
+}
+int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
+  return id->pMethods->xUnfetch(id, iOff, p);
+}
+#else
+/* No-op stubs to use when memory-mapped I/O is disabled */
+int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
+  *pp = 0;
+  return SQLITE_OK;
+}
+int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
+  return SQLITE_OK;
+}
+#endif
+
 /*
 ** The next group of routines are convenience wrappers around the
 ** VFS methods.
diff --git a/lib/libsqlite3/src/os.h b/lib/libsqlite3/src/os.h
index 1ec7d4ba11c..070a2ddd17f 100644
--- a/lib/libsqlite3/src/os.h
+++ b/lib/libsqlite3/src/os.h
@@ -99,14 +99,6 @@
 # define SQLITE_OS_WINRT 0
 #endif
 
-/*
-** When compiled for WinCE or WinRT, there is no concept of the current
-** directory.
- */
-#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
-# define SQLITE_CURDIR 1
-#endif
-
 /* If the SET_FULLSYNC macro is not defined above, then make it
 ** a no-op
 */
@@ -259,6 +251,8 @@ int sqlite3OsShmMap(sqlite3_file *,int,int,int,void volatile **);
 int sqlite3OsShmLock(sqlite3_file *id, int, int, int);
 void sqlite3OsShmBarrier(sqlite3_file *id);
 int sqlite3OsShmUnmap(sqlite3_file *id, int);
+int sqlite3OsFetch(sqlite3_file *id, i64, int, void **);
+int sqlite3OsUnfetch(sqlite3_file *, i64, void *);
 
 
 /* 
diff --git a/lib/libsqlite3/src/os_unix.c b/lib/libsqlite3/src/os_unix.c
index 315f1501888..abc23a452e7 100644
--- a/lib/libsqlite3/src/os_unix.c
+++ b/lib/libsqlite3/src/os_unix.c
@@ -126,7 +126,7 @@
 #include <time.h>
 #include <sys/time.h>
 #include <errno.h>
-#ifndef SQLITE_OMIT_WAL
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
 #include <sys/mman.h>
 #endif
 
@@ -225,6 +225,11 @@ struct unixFile {
   const char *zPath;                  /* Name of the file */
   unixShm *pShm;                      /* Shared memory segment information */
   int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
+  int nFetchOut;                      /* Number of outstanding xFetch refs */
+  sqlite3_int64 mmapSize;             /* Usable size of mapping at pMapRegion */
+  sqlite3_int64 mmapSizeActual;       /* Actual size of mapping at pMapRegion */
+  sqlite3_int64 mmapSizeMax;          /* Configured FCNTL_MMAP_SIZE value */
+  void *pMapRegion;                   /* Memory mapped region */
 #ifdef __QNXNTO__
   int sectorSize;                     /* Device sector size */
   int deviceCharacteristics;          /* Precomputed device characteristics */
@@ -249,7 +254,9 @@ struct unixFile {
   unsigned char transCntrChng;   /* True if the transaction counter changed */
   unsigned char dbUpdate;        /* True if any part of database file changed */
   unsigned char inNormalWrite;   /* True if in a normal write operation */
+
 #endif
+
 #ifdef SQLITE_TEST
   /* In test mode, increase the size of this structure a bit so that 
   ** it is larger than the struct CrashFile defined in test6.c.
@@ -273,6 +280,7 @@ struct unixFile {
 #define UNIXFILE_DELETE      0x20     /* Delete on close */
 #define UNIXFILE_URI         0x40     /* Filename might have query parameters */
 #define UNIXFILE_NOLOCK      0x80     /* Do no file locking */
+#define UNIXFILE_WARNED    0x0100     /* verifyDbFile() warnings have been issued */
 
 /*
 ** Include code that is common to all os_*.c files
@@ -307,6 +315,17 @@ struct unixFile {
 #endif
 
 /*
+** HAVE_MREMAP defaults to true on Linux and false everywhere else.
+*/
+#if !defined(HAVE_MREMAP)
+# if defined(__linux__) && defined(_GNU_SOURCE)
+#  define HAVE_MREMAP 1
+# else
+#  define HAVE_MREMAP 0
+# endif
+#endif
+
+/*
 ** Different Unix systems declare open() in different ways.  Same use
 ** open(const char*,int,mode_t).  Others use open(const char*,int,...).
 ** The difference is important when using a pointer to the function.
@@ -337,7 +356,7 @@ static int openDirectory(const char*, int*);
 ** to all overrideable system calls.
 */
 static struct unix_syscall {
-  const char *zName;            /* Name of the sytem call */
+  const char *zName;            /* Name of the system call */
   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
   sqlite3_syscall_ptr pDefault; /* Default value */
 } aSyscall[] = {
@@ -412,11 +431,7 @@ static struct unix_syscall {
 #define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
                     aSyscall[13].pCurrent)
 
-#if SQLITE_ENABLE_LOCKING_STYLE
   { "fchmod",       (sqlite3_syscall_ptr)fchmod,     0  },
-#else
-  { "fchmod",       (sqlite3_syscall_ptr)0,          0  },
-#endif
 #define osFchmod    ((int(*)(int,mode_t))aSyscall[14].pCurrent)
 
 #if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
@@ -441,8 +456,18 @@ static struct unix_syscall {
   { "fchown",       (sqlite3_syscall_ptr)posixFchown,     0 },
 #define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)
 
-  { "umask",        (sqlite3_syscall_ptr)umask,           0 },
-#define osUmask     ((mode_t(*)(mode_t))aSyscall[21].pCurrent)
+  { "mmap",       (sqlite3_syscall_ptr)mmap,     0 },
+#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[21].pCurrent)
+
+  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
+#define osMunmap ((void*(*)(void*,size_t))aSyscall[22].pCurrent)
+
+#if HAVE_MREMAP
+  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
+#else
+  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[23].pCurrent)
 
 }; /* End of the overrideable system calls */
 
@@ -548,14 +573,7 @@ static const char *unixNextSystemCall(sqlite3_vfs *p, const char *zName){
 */
 static int robust_open(const char *z, int f, mode_t m){
   int fd;
-  mode_t m2;
-  mode_t origM = 0;
-  if( m==0 ){
-    m2 = SQLITE_DEFAULT_FILE_PERMISSIONS;
-  }else{
-    m2 = m;
-    origM = osUmask(0);
-  }
+  mode_t m2 = m ? m : SQLITE_DEFAULT_FILE_PERMISSIONS;
   do{
 #if defined(O_CLOEXEC)
     fd = osOpen(z,f|O_CLOEXEC,m2);
@@ -563,12 +581,20 @@ static int robust_open(const char *z, int f, mode_t m){
     fd = osOpen(z,f,m2);
 #endif
   }while( fd<0 && errno==EINTR );
-  if( m ){
-    osUmask(origM);
-  }
+  if( fd>=0 ){
+    if( m!=0 ){
+      struct stat statbuf;
+      if( osFstat(fd, &statbuf)==0 
+       && statbuf.st_size==0
+       && (statbuf.st_mode&0777)!=m 
+      ){
+        osFchmod(fd, m);
+      }
+    }
 #if defined(FD_CLOEXEC) && (!defined(O_CLOEXEC) || O_CLOEXEC==0)
-  if( fd>=0 ) osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
+    osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
 #endif
+  }
   return fd;
 }
 
@@ -774,7 +800,6 @@ static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
 }
 
 
-
 /******************************************************************************
 ****************** Begin Unique File ID Utility Used By VxWorks ***************
 **
@@ -1110,7 +1135,6 @@ static int unixLogErrorAtLine(
   zErr = strerror(iErrno);
 #endif
 
-  assert( errcode!=SQLITE_OK );
   if( zPath==0 ) zPath = "";
   sqlite3_log(errcode,
       "os_unix.c:%d: (%d) %s(%s) - %s",
@@ -1277,6 +1301,50 @@ static int findInodeInfo(
 
 
 /*
+** Check a unixFile that is a database.  Verify the following:
+**
+** (1) There is exactly one hard link on the file
+** (2) The file is not a symbolic link
+** (3) The file has not been renamed or unlinked
+**
+** Issue sqlite3_log(SQLITE_WARNING,...) messages if anything is not right.
+*/
+static void verifyDbFile(unixFile *pFile){
+  struct stat buf;
+  int rc;
+  if( pFile->ctrlFlags & UNIXFILE_WARNED ){
+    /* One or more of the following warnings have already been issued.  Do not
+    ** repeat them so as not to clutter the error log */
+    return;
+  }
+  rc = osFstat(pFile->h, &buf);
+  if( rc!=0 ){
+    sqlite3_log(SQLITE_WARNING, "cannot fstat db file %s", pFile->zPath);
+    pFile->ctrlFlags |= UNIXFILE_WARNED;
+    return;
+  }
+  if( buf.st_nlink==0 && (pFile->ctrlFlags & UNIXFILE_DELETE)==0 ){
+    sqlite3_log(SQLITE_WARNING, "file unlinked while open: %s", pFile->zPath);
+    pFile->ctrlFlags |= UNIXFILE_WARNED;
+    return;
+  }
+  if( buf.st_nlink>1 ){
+    sqlite3_log(SQLITE_WARNING, "multiple links to file: %s", pFile->zPath);
+    pFile->ctrlFlags |= UNIXFILE_WARNED;
+    return;
+  }
+  if( pFile->pInode!=0
+   && ((rc = osStat(pFile->zPath, &buf))!=0
+       || buf.st_ino!=pFile->pInode->fileId.ino)
+  ){
+    sqlite3_log(SQLITE_WARNING, "file renamed while open: %s", pFile->zPath);
+    pFile->ctrlFlags |= UNIXFILE_WARNED;
+    return;
+  }
+}
+
+
+/*
 ** This routine checks if there is a RESERVED lock held on the specified
 ** file by this or any other process. If such a lock is held, set *pResOut
 ** to a non-zero value otherwise *pResOut is set to zero.  The return value
@@ -1806,9 +1874,13 @@ end_unlock:
 ** the requested locking level, this routine is a no-op.
 */
 static int unixUnlock(sqlite3_file *id, int eFileLock){
+  assert( eFileLock==SHARED_LOCK || ((unixFile *)id)->nFetchOut==0 );
   return posixUnlock(id, eFileLock, 0);
 }
 
+static int unixMapfile(unixFile *pFd, i64 nByte);
+static void unixUnmapfile(unixFile *pFd);
+
 /*
 ** This function performs the parts of the "close file" operation 
 ** common to all locking schemes. It closes the directory and file
@@ -1821,6 +1893,7 @@ static int unixUnlock(sqlite3_file *id, int eFileLock){
 */
 static int closeUnixFile(sqlite3_file *id){
   unixFile *pFile = (unixFile*)id;
+  unixUnmapfile(pFile);
   if( pFile->h>=0 ){
     robust_close(pFile, pFile->h, __LINE__);
     pFile->h = -1;
@@ -1847,6 +1920,7 @@ static int closeUnixFile(sqlite3_file *id){
 static int unixClose(sqlite3_file *id){
   int rc = SQLITE_OK;
   unixFile *pFile = (unixFile *)id;
+  verifyDbFile(pFile);
   unixUnlock(id, NO_LOCK);
   unixEnterMutex();
 
@@ -1915,7 +1989,7 @@ static int nolockClose(sqlite3_file *id) {
 /******************************************************************************
 ************************* Begin dot-file Locking ******************************
 **
-** The dotfile locking implementation uses the existance of separate lock
+** The dotfile locking implementation uses the existence of separate lock
 ** files (really a directory) to control access to the database.  This works
 ** on just about every filesystem imaginable.  But there are serious downsides:
 **
@@ -1930,7 +2004,7 @@ static int nolockClose(sqlite3_file *id) {
 **
 ** Dotfile locking works by creating a subdirectory in the same directory as
 ** the database and with the same name but with a ".lock" extension added.
-** The existance of a lock directory implies an EXCLUSIVE lock.  All other
+** The existence of a lock directory implies an EXCLUSIVE lock.  All other
 ** lock types (SHARED, RESERVED, PENDING) are mapped into EXCLUSIVE.
 */
 
@@ -3078,6 +3152,8 @@ static int unixRead(
   unixFile *pFile = (unixFile *)id;
   int got;
   assert( id );
+  assert( offset>=0 );
+  assert( amt>0 );
 
   /* If this is a database file (not a journal, master-journal or temp
   ** file), the bytes in the locking range should never be read or written. */
@@ -3088,6 +3164,23 @@ static int unixRead(
   );
 #endif
 
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this read request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
+      return SQLITE_OK;
+    }else{
+      int nCopy = pFile->mmapSize - offset;
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
+
   got = seekAndRead(pFile, offset, pBuf, amt);
   if( got==amt ){
     return SQLITE_OK;
@@ -3103,46 +3196,59 @@ static int unixRead(
 }
 
 /*
-** Seek to the offset in id->offset then read cnt bytes into pBuf.
-** Return the number of bytes actually read.  Update the offset.
-**
-** To avoid stomping the errno value on a failed write the lastErrno value
-** is set before returning.
+** Attempt to seek the file-descriptor passed as the first argument to
+** absolute offset iOff, then attempt to write nBuf bytes of data from
+** pBuf to it. If an error occurs, return -1 and set *piErrno. Otherwise, 
+** return the actual number of bytes written (which may be less than
+** nBuf).
 */
-static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
-  int got;
-#if (!defined(USE_PREAD) && !defined(USE_PREAD64))
-  i64 newOffset;
-#endif
-  assert( cnt==(cnt&0x1ffff) );
-  cnt &= 0x1ffff;
+static int seekAndWriteFd(
+  int fd,                         /* File descriptor to write to */
+  i64 iOff,                       /* File offset to begin writing at */
+  const void *pBuf,               /* Copy data from this buffer to the file */
+  int nBuf,                       /* Size of buffer pBuf in bytes */
+  int *piErrno                    /* OUT: Error number if error occurs */
+){
+  int rc = 0;                     /* Value returned by system call */
+
+  assert( nBuf==(nBuf&0x1ffff) );
+  nBuf &= 0x1ffff;
   TIMER_START;
+
 #if defined(USE_PREAD)
-  do{ got = osPwrite(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
+  do{ rc = osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );
 #elif defined(USE_PREAD64)
-  do{ got = osPwrite64(id->h, pBuf, cnt, offset);}while( got<0 && errno==EINTR);
+  do{ rc = osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);
 #else
   do{
-    newOffset = lseek(id->h, offset, SEEK_SET);
-    SimulateIOError( newOffset-- );
-    if( newOffset!=offset ){
-      if( newOffset == -1 ){
-        ((unixFile*)id)->lastErrno = errno;
-      }else{
-        ((unixFile*)id)->lastErrno = 0;
-      }
+    i64 iSeek = lseek(fd, iOff, SEEK_SET);
+    SimulateIOError( iSeek-- );
+
+    if( iSeek!=iOff ){
+      if( piErrno ) *piErrno = (iSeek==-1 ? errno : 0);
       return -1;
     }
-    got = osWrite(id->h, pBuf, cnt);
-  }while( got<0 && errno==EINTR );
+    rc = osWrite(fd, pBuf, nBuf);
+  }while( rc<0 && errno==EINTR );
 #endif
+
   TIMER_END;
-  if( got<0 ){
-    ((unixFile*)id)->lastErrno = errno;
-  }
+  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", fd, rc, iOff, TIMER_ELAPSED));
+
+  if( rc<0 && piErrno ) *piErrno = errno;
+  return rc;
+}
+
 
-  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));
-  return got;
+/*
+** Seek to the offset in id->offset then read cnt bytes into pBuf.
+** Return the number of bytes actually read.  Update the offset.
+**
+** To avoid stomping the errno value on a failed write the lastErrno value
+** is set before returning.
+*/
+static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
+  return seekAndWriteFd(id->h, offset, pBuf, cnt, &id->lastErrno);
 }
 
 
@@ -3192,6 +3298,23 @@ static int unixWrite(
   }
 #endif
 
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this write request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
+      return SQLITE_OK;
+    }else{
+      int nCopy = pFile->mmapSize - offset;
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
+
   while( amt>0 && (wrote = seekAndWrite(pFile, offset, pBuf, amt))>0 ){
     amt -= wrote;
     offset += wrote;
@@ -3419,7 +3542,7 @@ static int unixSync(sqlite3_file *id, int flags){
   }
 
   /* Also fsync the directory containing the file if the DIRSYNC flag
-  ** is set.  This is a one-time occurrance.  Many systems (examples: AIX)
+  ** is set.  This is a one-time occurrence.  Many systems (examples: AIX)
   ** are unable to fsync a directory, so ignore errors on the fsync.
   */
   if( pFile->ctrlFlags & UNIXFILE_DIRSYNC ){
@@ -3474,6 +3597,14 @@ static int unixTruncate(sqlite3_file *id, i64 nByte){
     }
 #endif
 
+    /* If the file was just truncated to a size smaller than the currently
+    ** mapped region, reduce the effective mapping size as well. SQLite will
+    ** use read() and write() to access data beyond this point from now on.  
+    */
+    if( nByte<pFile->mmapSize ){
+      pFile->mmapSize = nByte;
+    }
+
     return SQLITE_OK;
   }
 }
@@ -3562,6 +3693,19 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
     }
   }
 
+  if( pFile->mmapSizeMax>0 && nByte>pFile->mmapSize ){
+    int rc;
+    if( pFile->szChunk<=0 ){
+      if( robust_ftruncate(pFile->h, nByte) ){
+        pFile->lastErrno = errno;
+        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
+      }
+    }
+
+    rc = unixMapfile(pFile, nByte);
+    return rc;
+  }
+
   return SQLITE_OK;
 }
 
@@ -3629,6 +3773,18 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       }
       return SQLITE_OK;
     }
+    case SQLITE_FCNTL_MMAP_SIZE: {
+      i64 newLimit = *(i64*)pArg;
+      if( newLimit>sqlite3GlobalConfig.mxMmap ){
+        newLimit = sqlite3GlobalConfig.mxMmap;
+      }
+      *(i64*)pArg = pFile->mmapSizeMax;
+      if( newLimit>=0 ){
+        pFile->mmapSizeMax = newLimit;
+        if( newLimit<pFile->mmapSize ) pFile->mmapSize = newLimit;
+      }
+      return SQLITE_OK;
+    }
 #ifdef SQLITE_DEBUG
     /* The pager calls this method to signal that it has done
     ** a rollback and that the database is therefore unchanged and
@@ -3941,7 +4097,7 @@ static void unixShmPurge(unixFile *pFd){
     sqlite3_mutex_free(p->mutex);
     for(i=0; i<p->nRegion; i++){
       if( p->h>=0 ){
-        munmap(p->apRegion[i], p->szRegion);
+        osMunmap(p->apRegion[i], p->szRegion);
       }else{
         sqlite3_free(p->apRegion[i]);
       }
@@ -4181,24 +4337,32 @@ static int unixShmMap(
       if( sStat.st_size<nByte ){
         /* The requested memory region does not exist. If bExtend is set to
         ** false, exit early. *pp will be set to NULL and SQLITE_OK returned.
-        **
-        ** Alternatively, if bExtend is true, use ftruncate() to allocate
-        ** the requested memory region.
         */
-        if( !bExtend ) goto shmpage_out;
-#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
-        if( osFallocate(pShmNode->h, sStat.st_size, nByte)!=0 ){
-          rc = unixLogError(SQLITE_IOERR_SHMSIZE, "fallocate",
-                            pShmNode->zFilename);
+        if( !bExtend ){
           goto shmpage_out;
         }
-#else
-        if( robust_ftruncate(pShmNode->h, nByte) ){
-          rc = unixLogError(SQLITE_IOERR_SHMSIZE, "ftruncate",
-                            pShmNode->zFilename);
-          goto shmpage_out;
+
+        /* Alternatively, if bExtend is true, extend the file. Do this by
+        ** writing a single byte to the end of each (OS) page being
+        ** allocated or extended. Technically, we need only write to the
+        ** last page in order to extend the file. But writing to all new
+        ** pages forces the OS to allocate them immediately, which reduces
+        ** the chances of SIGBUS while accessing the mapped region later on.
+        */
+        else{
+          static const int pgsz = 4096;
+          int iPg;
+
+          /* Write to the last byte of each newly allocated or extended page */
+          assert( (nByte % pgsz)==0 );
+          for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){
+            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, 0)!=1 ){
+              const char *zFile = pShmNode->zFilename;
+              rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);
+              goto shmpage_out;
+            }
+          }
         }
-#endif
       }
     }
 
@@ -4214,7 +4378,7 @@ static int unixShmMap(
     while(pShmNode->nRegion<=iRegion){
       void *pMem;
       if( pShmNode->h>=0 ){
-        pMem = mmap(0, szRegion,
+        pMem = osMmap(0, szRegion,
             pShmNode->isReadonly ? PROT_READ : PROT_READ|PROT_WRITE, 
             MAP_SHARED, pShmNode->h, szRegion*(i64)pShmNode->nRegion
         );
@@ -4432,6 +4596,236 @@ static int unixShmUnmap(
 #endif /* #ifndef SQLITE_OMIT_WAL */
 
 /*
+** If it is currently memory mapped, unmap file pFd.
+*/
+static void unixUnmapfile(unixFile *pFd){
+  assert( pFd->nFetchOut==0 );
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFd->pMapRegion ){
+    osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);
+    pFd->pMapRegion = 0;
+    pFd->mmapSize = 0;
+    pFd->mmapSizeActual = 0;
+  }
+#endif
+}
+
+#if SQLITE_MAX_MMAP_SIZE>0
+/*
+** Return the system page size.
+*/
+static int unixGetPagesize(void){
+#if HAVE_MREMAP
+  return 512;
+#elif defined(_BSD_SOURCE)
+  return getpagesize();
+#else
+  return (int)sysconf(_SC_PAGESIZE);
+#endif
+}
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+
+#if SQLITE_MAX_MMAP_SIZE>0
+/*
+** Attempt to set the size of the memory mapping maintained by file 
+** descriptor pFd to nNew bytes. Any existing mapping is discarded.
+**
+** If successful, this function sets the following variables:
+**
+**       unixFile.pMapRegion
+**       unixFile.mmapSize
+**       unixFile.mmapSizeActual
+**
+** If unsuccessful, an error message is logged via sqlite3_log() and
+** the three variables above are zeroed. In this case SQLite should
+** continue accessing the database using the xRead() and xWrite()
+** methods.
+*/
+static void unixRemapfile(
+  unixFile *pFd,                  /* File descriptor object */
+  i64 nNew                        /* Required mapping size */
+){
+  const char *zErr = "mmap";
+  int h = pFd->h;                      /* File descriptor open on db file */
+  u8 *pOrig = (u8 *)pFd->pMapRegion;   /* Pointer to current file mapping */
+  i64 nOrig = pFd->mmapSizeActual;     /* Size of pOrig region in bytes */
+  u8 *pNew = 0;                        /* Location of new mapping */
+  int flags = PROT_READ;               /* Flags to pass to mmap() */
+
+  assert( pFd->nFetchOut==0 );
+  assert( nNew>pFd->mmapSize );
+  assert( nNew<=pFd->mmapSizeMax );
+  assert( nNew>0 );
+  assert( pFd->mmapSizeActual>=pFd->mmapSize );
+  assert( MAP_FAILED!=0 );
+
+  if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;
+
+  if( pOrig ){
+    const int szSyspage = unixGetPagesize();
+    i64 nReuse = (pFd->mmapSize & ~(szSyspage-1));
+    u8 *pReq = &pOrig[nReuse];
+
+    /* Unmap any pages of the existing mapping that cannot be reused. */
+    if( nReuse!=nOrig ){
+      osMunmap(pReq, nOrig-nReuse);
+    }
+
+#if HAVE_MREMAP
+    pNew = osMremap(pOrig, nReuse, nNew, MREMAP_MAYMOVE);
+    zErr = "mremap";
+#else
+    pNew = osMmap(pReq, nNew-nReuse, flags, MAP_SHARED, h, nReuse);
+    if( pNew!=MAP_FAILED ){
+      if( pNew!=pReq ){
+        osMunmap(pNew, nNew - nReuse);
+        pNew = 0;
+      }else{
+        pNew = pOrig;
+      }
+    }
+#endif
+
+    /* The attempt to extend the existing mapping failed. Free it. */
+    if( pNew==MAP_FAILED || pNew==0 ){
+      osMunmap(pOrig, nReuse);
+    }
+  }
+
+  /* If pNew is still NULL, try to create an entirely new mapping. */
+  if( pNew==0 ){
+    pNew = osMmap(0, nNew, flags, MAP_SHARED, h, 0);
+  }
+
+  if( pNew==MAP_FAILED ){
+    pNew = 0;
+    nNew = 0;
+    unixLogError(SQLITE_OK, zErr, pFd->zPath);
+
+    /* If the mmap() above failed, assume that all subsequent mmap() calls
+    ** will probably fail too. Fall back to using xRead/xWrite exclusively
+    ** in this case.  */
+    pFd->mmapSizeMax = 0;
+  }
+  pFd->pMapRegion = (void *)pNew;
+  pFd->mmapSize = pFd->mmapSizeActual = nNew;
+}
+#endif
+
+/*
+** Memory map or remap the file opened by file-descriptor pFd (if the file
+** is already mapped, the existing mapping is replaced by the new). Or, if 
+** there already exists a mapping for this file, and there are still 
+** outstanding xFetch() references to it, this function is a no-op.
+**
+** If parameter nByte is non-negative, then it is the requested size of 
+** the mapping to create. Otherwise, if nByte is less than zero, then the 
+** requested size is the size of the file on disk. The actual size of the
+** created mapping is either the requested size or the value configured 
+** using SQLITE_FCNTL_MMAP_LIMIT, whichever is smaller.
+**
+** SQLITE_OK is returned if no error occurs (even if the mapping is not
+** recreated as a result of outstanding references) or an SQLite error
+** code otherwise.
+*/
+static int unixMapfile(unixFile *pFd, i64 nByte){
+#if SQLITE_MAX_MMAP_SIZE>0
+  i64 nMap = nByte;
+  int rc;
+
+  assert( nMap>=0 || pFd->nFetchOut==0 );
+  if( pFd->nFetchOut>0 ) return SQLITE_OK;
+
+  if( nMap<0 ){
+    struct stat statbuf;          /* Low-level file information */
+    rc = osFstat(pFd->h, &statbuf);
+    if( rc!=SQLITE_OK ){
+      return SQLITE_IOERR_FSTAT;
+    }
+    nMap = statbuf.st_size;
+  }
+  if( nMap>pFd->mmapSizeMax ){
+    nMap = pFd->mmapSizeMax;
+  }
+
+  if( nMap!=pFd->mmapSize ){
+    if( nMap>0 ){
+      unixRemapfile(pFd, nMap);
+    }else{
+      unixUnmapfile(pFd);
+    }
+  }
+#endif
+
+  return SQLITE_OK;
+}
+
+/*
+** If possible, return a pointer to a mapping of file fd starting at offset
+** iOff. The mapping must be valid for at least nAmt bytes.
+**
+** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
+** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
+** Finally, if an error does occur, return an SQLite error code. The final
+** value of *pp is undefined in this case.
+**
+** If this function does return a pointer, the caller must eventually 
+** release the reference by calling unixUnfetch().
+*/
+static int unixFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
+#if SQLITE_MAX_MMAP_SIZE>0
+  unixFile *pFd = (unixFile *)fd;   /* The underlying database file */
+#endif
+  *pp = 0;
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFd->mmapSizeMax>0 ){
+    if( pFd->pMapRegion==0 ){
+      int rc = unixMapfile(pFd, -1);
+      if( rc!=SQLITE_OK ) return rc;
+    }
+    if( pFd->mmapSize >= iOff+nAmt ){
+      *pp = &((u8 *)pFd->pMapRegion)[iOff];
+      pFd->nFetchOut++;
+    }
+  }
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** If the third argument is non-NULL, then this function releases a 
+** reference obtained by an earlier call to unixFetch(). The second
+** argument passed to this function must be the same as the corresponding
+** argument that was passed to the unixFetch() invocation. 
+**
+** Or, if the third argument is NULL, then this function is being called 
+** to inform the VFS layer that, according to POSIX, any existing mapping 
+** may now be invalid and should be unmapped.
+*/
+static int unixUnfetch(sqlite3_file *fd, i64 iOff, void *p){
+  unixFile *pFd = (unixFile *)fd;   /* The underlying database file */
+  UNUSED_PARAMETER(iOff);
+
+  /* If p==0 (unmap the entire file) then there must be no outstanding 
+  ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
+  ** then there must be at least one outstanding.  */
+  assert( (p==0)==(pFd->nFetchOut==0) );
+
+  /* If p!=0, it must match the iOff value. */
+  assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
+
+  if( p ){
+    pFd->nFetchOut--;
+  }else{
+    unixUnmapfile(pFd);
+  }
+
+  assert( pFd->nFetchOut>=0 );
+  return SQLITE_OK;
+}
+
+/*
 ** Here ends the implementation of all sqlite3_file methods.
 **
 ********************** End sqlite3_file Methods *******************************
@@ -4489,7 +4883,9 @@ static const sqlite3_io_methods METHOD = {                                   \
    unixShmMap,                 /* xShmMap */                                 \
    unixShmLock,                /* xShmLock */                                \
    unixShmBarrier,             /* xShmBarrier */                             \
-   unixShmUnmap                /* xShmUnmap */                               \
+   unixShmUnmap,               /* xShmUnmap */                               \
+   unixFetch,                  /* xFetch */                                  \
+   unixUnfetch,                /* xUnfetch */                                \
 };                                                                           \
 static const sqlite3_io_methods *FINDER##Impl(const char *z, unixFile *p){   \
   UNUSED_PARAMETER(z); UNUSED_PARAMETER(p);                                  \
@@ -4506,7 +4902,7 @@ static const sqlite3_io_methods *(*const FINDER)(const char*,unixFile *p)    \
 IOMETHODS(
   posixIoFinder,            /* Finder function name */
   posixIoMethods,           /* sqlite3_io_methods object name */
-  2,                        /* shared memory is enabled */
+  3,                        /* shared memory and mmap are enabled */
   unixClose,                /* xClose method */
   unixLock,                 /* xLock method */
   unixUnlock,               /* xUnlock method */
@@ -4757,11 +5153,12 @@ static int fillInUnixFile(
   pNew->pVfs = pVfs;
   pNew->zPath = zFilename;
   pNew->ctrlFlags = (u8)ctrlFlags;
+  pNew->mmapSizeMax = sqlite3GlobalConfig.szMmap;
   if( sqlite3_uri_boolean(((ctrlFlags & UNIXFILE_URI) ? zFilename : 0),
                            "psow", SQLITE_POWERSAFE_OVERWRITE) ){
     pNew->ctrlFlags |= UNIXFILE_PSOW;
   }
-  if( memcmp(pVfs->zName,"unix-excl",10)==0 ){
+  if( strcmp(pVfs->zName,"unix-excl")==0 ){
     pNew->ctrlFlags |= UNIXFILE_EXCL;
   }
 
@@ -4793,7 +5190,7 @@ static int fillInUnixFile(
     unixEnterMutex();
     rc = findInodeInfo(pNew, &pNew->pInode);
     if( rc!=SQLITE_OK ){
-      /* If an error occured in findInodeInfo(), close the file descriptor
+      /* If an error occurred in findInodeInfo(), close the file descriptor
       ** immediately, before releasing the mutex. findInodeInfo() may fail
       ** in two scenarios:
       **
@@ -4892,15 +5289,15 @@ static int fillInUnixFile(
     if( h>=0 ) robust_close(pNew, h, __LINE__);
     h = -1;
     osUnlink(zFilename);
-    isDelete = 0;
+    pNew->ctrlFlags |= UNIXFILE_DELETE;
   }
-  if( isDelete ) pNew->ctrlFlags |= UNIXFILE_DELETE;
 #endif
   if( rc!=SQLITE_OK ){
     if( h>=0 ) robust_close(pNew, h, __LINE__);
   }else{
     pNew->pMethod = pLockingStyle;
     OpenCounter(+1);
+    verifyDbFile(pNew);
   }
   return rc;
 }
@@ -5431,7 +5828,7 @@ static int unixDelete(
 }
 
 /*
-** Test the existance of or access permissions of file zPath. The
+** Test the existence of or access permissions of file zPath. The
 ** test performed depends on the value of flags:
 **
 **     SQLITE_ACCESS_EXISTS: Return 1 if the file exists
@@ -6994,7 +7391,7 @@ int sqlite3_os_init(void){
 
   /* Double-check that the aSyscall[] array has been constructed
   ** correctly.  See ticket [bb3a86e890c8e96ab] */
-  assert( ArraySize(aSyscall)==22 );
+  assert( ArraySize(aSyscall)==24 );
 
   /* Register all VFSes defined in the aVfs[] array */
   for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
diff --git a/lib/libsqlite3/src/os_win.c b/lib/libsqlite3/src/os_win.c
index 107370c41be..aeb08814b3d 100644
--- a/lib/libsqlite3/src/os_win.c
+++ b/lib/libsqlite3/src/os_win.c
@@ -150,11 +150,20 @@ struct winFile {
   winceLock local;        /* Locks obtained by this instance of winFile */
   winceLock *shared;      /* Global shared lock memory for the file  */
 #endif
+#if SQLITE_MAX_MMAP_SIZE>0
+  int nFetchOut;                /* Number of outstanding xFetch references */
+  HANDLE hMap;                  /* Handle for accessing memory mapping */
+  void *pMapRegion;             /* Area memory mapped */
+  sqlite3_int64 mmapSize;       /* Usable size of mapped region */
+  sqlite3_int64 mmapSizeActual; /* Actual size of mapped region */
+  sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */
+#endif
 };
 
 /*
 ** Allowed values for winFile.ctrlFlags
 */
+#define WINFILE_RDONLY          0x02   /* Connection is read only */
 #define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
 #define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
 
@@ -308,7 +317,7 @@ static int sqlite3_os_type = 0;
 ** to all overrideable system calls.
 */
 static struct win_syscall {
-  const char *zName;            /* Name of the sytem call */
+  const char *zName;            /* Name of the system call */
   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
   sqlite3_syscall_ptr pDefault; /* Default value */
 } aSyscall[] = {
@@ -988,7 +997,7 @@ static const char *winNextSystemCall(sqlite3_vfs *p, const char *zName){
 ** (if available).
 */
 
-void sqlite3_win32_write_debug(char *zBuf, int nBuf){
+void sqlite3_win32_write_debug(const char *zBuf, int nBuf){
   char zDbgBuf[SQLITE_WIN32_DBG_BUF_SIZE];
   int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */
   if( nMin<-1 ) nMin = -1; /* all negative values become -1. */
@@ -1514,7 +1523,7 @@ static int getLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
   }
 #endif
   if( 0 == dwLen ){
-    sqlite3_snprintf(nBuf, zBuf, "OsError 0x%x (%u)", lastErrno, lastErrno);
+    sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);
   }else{
     /* copy a maximum of nBuf chars to output buffer */
     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);
@@ -1557,7 +1566,7 @@ static int winLogErrorAtLine(
   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
   zMsg[i] = 0;
   sqlite3_log(errcode,
-      "os_win.c:%d: (%d) %s(%s) - %s",
+      "os_win.c:%d: (%lu) %s(%s) - %s",
       iLine, lastErrno, zFunc, zPath, zMsg
   );
 
@@ -1621,9 +1630,10 @@ static void logIoerr(int nRetry){
 /*************************************************************************
 ** This section contains code for WinCE only.
 */
+#if !defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API
 /*
-** Windows CE does not have a localtime() function.  So create a
-** substitute.
+** The MSVC CRT on Windows CE may not have a localtime() function.  So
+** create a substitute.
 */
 #include <time.h>
 struct tm *__cdecl localtime(const time_t *t)
@@ -1647,6 +1657,7 @@ struct tm *__cdecl localtime(const time_t *t)
   y.tm_sec = pTm.wSecond;
   return &y;
 }
+#endif
 
 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
 
@@ -1668,15 +1679,17 @@ static void winceMutexAcquire(HANDLE h){
 ** Create the mutex and shared memory used for locking in the file
 ** descriptor pFile
 */
-static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
+static int winceCreateLock(const char *zFilename, winFile *pFile){
   LPWSTR zTok;
   LPWSTR zName;
+  DWORD lastErrno;
+  BOOL bLogged = FALSE;
   BOOL bInit = TRUE;
 
   zName = utf8ToUnicode(zFilename);
   if( zName==0 ){
     /* out of memory */
-    return FALSE;
+    return SQLITE_IOERR_NOMEM;
   }
 
   /* Initialize the local lockdata */
@@ -1693,9 +1706,10 @@ static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
   pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);
   if (!pFile->hMutex){
     pFile->lastErrno = osGetLastError();
-    winLogError(SQLITE_ERROR, pFile->lastErrno, "winceCreateLock1", zFilename);
+    winLogError(SQLITE_IOERR, pFile->lastErrno,
+                "winceCreateLock1", zFilename);
     sqlite3_free(zName);
-    return FALSE;
+    return SQLITE_IOERR;
   }
 
   /* Acquire the mutex before continuing */
@@ -1712,41 +1726,49 @@ static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
 
   /* Set a flag that indicates we're the first to create the memory so it 
   ** must be zero-initialized */
-  if (osGetLastError() == ERROR_ALREADY_EXISTS){
+  lastErrno = osGetLastError();
+  if (lastErrno == ERROR_ALREADY_EXISTS){
     bInit = FALSE;
   }
 
   sqlite3_free(zName);
 
   /* If we succeeded in making the shared memory handle, map it. */
-  if (pFile->hShared){
+  if( pFile->hShared ){
     pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared, 
              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
     /* If mapping failed, close the shared memory handle and erase it */
-    if (!pFile->shared){
+    if( !pFile->shared ){
       pFile->lastErrno = osGetLastError();
-      winLogError(SQLITE_ERROR, pFile->lastErrno,
-               "winceCreateLock2", zFilename);
+      winLogError(SQLITE_IOERR, pFile->lastErrno,
+                  "winceCreateLock2", zFilename);
+      bLogged = TRUE;
       osCloseHandle(pFile->hShared);
       pFile->hShared = NULL;
     }
   }
 
   /* If shared memory could not be created, then close the mutex and fail */
-  if (pFile->hShared == NULL){
+  if( pFile->hShared==NULL ){
+    if( !bLogged ){
+      pFile->lastErrno = lastErrno;
+      winLogError(SQLITE_IOERR, pFile->lastErrno,
+                  "winceCreateLock3", zFilename);
+      bLogged = TRUE;
+    }
     winceMutexRelease(pFile->hMutex);
     osCloseHandle(pFile->hMutex);
     pFile->hMutex = NULL;
-    return FALSE;
+    return SQLITE_IOERR;
   }
   
   /* Initialize the shared memory if we're supposed to */
-  if (bInit) {
+  if( bInit ){
     memset(pFile->shared, 0, sizeof(winceLock));
   }
 
   winceMutexRelease(pFile->hMutex);
-  return TRUE;
+  return SQLITE_OK;
 }
 
 /*
@@ -1825,7 +1847,8 @@ static BOOL winceLockFile(
   }
 
   /* Want a pending lock? */
-  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE && nNumberOfBytesToLockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
+           && nNumberOfBytesToLockLow == 1){
     /* If no pending lock has been acquired, then acquire it */
     if (pFile->shared->bPending == 0) {
       pFile->shared->bPending = TRUE;
@@ -1835,7 +1858,8 @@ static BOOL winceLockFile(
   }
 
   /* Want a reserved lock? */
-  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE && nNumberOfBytesToLockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
+           && nNumberOfBytesToLockLow == 1){
     if (pFile->shared->bReserved == 0) {
       pFile->shared->bReserved = TRUE;
       pFile->local.bReserved = TRUE;
@@ -1878,7 +1902,8 @@ static BOOL winceUnlockFile(
 
     /* Did we just have a reader lock? */
     else if (pFile->local.nReaders){
-      assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE || nNumberOfBytesToUnlockLow == 1);
+      assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE
+             || nNumberOfBytesToUnlockLow == 1);
       pFile->local.nReaders --;
       if (pFile->local.nReaders == 0)
       {
@@ -1889,7 +1914,8 @@ static BOOL winceUnlockFile(
   }
 
   /* Releasing a pending lock */
-  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE && nNumberOfBytesToUnlockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
+           && nNumberOfBytesToUnlockLow == 1){
     if (pFile->local.bPending){
       pFile->local.bPending = FALSE;
       pFile->shared->bPending = FALSE;
@@ -1897,7 +1923,8 @@ static BOOL winceUnlockFile(
     }
   }
   /* Releasing a reserved lock */
-  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE && nNumberOfBytesToUnlockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
+           && nNumberOfBytesToUnlockLow == 1){
     if (pFile->local.bReserved) {
       pFile->local.bReserved = FALSE;
       pFile->shared->bReserved = FALSE;
@@ -2000,6 +2027,8 @@ static int seekWinFile(winFile *pFile, sqlite3_int64 iOffset){
   DWORD dwRet;                    /* Value returned by SetFilePointer() */
   DWORD lastErrno;                /* Value returned by GetLastError() */
 
+  OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));
+
   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
   lowerBits = (LONG)(iOffset & 0xffffffff);
 
@@ -2007,7 +2036,7 @@ static int seekWinFile(winFile *pFile, sqlite3_int64 iOffset){
   ** containing the lower 32-bits of the new file-offset. Or, if it fails,
   ** it returns INVALID_SET_FILE_POINTER. However according to MSDN, 
   ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine 
-  ** whether an error has actually occured, it is also necessary to call 
+  ** whether an error has actually occurred, it is also necessary to call 
   ** GetLastError().
   */
   dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
@@ -2017,9 +2046,11 @@ static int seekWinFile(winFile *pFile, sqlite3_int64 iOffset){
     pFile->lastErrno = lastErrno;
     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
              "seekWinFile", pFile->zPath);
+    OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
     return 1;
   }
 
+  OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
   return 0;
 #else
   /*
@@ -2036,13 +2067,20 @@ static int seekWinFile(winFile *pFile, sqlite3_int64 iOffset){
     pFile->lastErrno = osGetLastError();
     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
              "seekWinFile", pFile->zPath);
+    OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
     return 1;
   }
 
+  OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
   return 0;
 #endif
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/* Forward references to VFS methods */
+static int winUnmapfile(winFile*);
+#endif
+
 /*
 ** Close a file.
 **
@@ -2062,7 +2100,14 @@ static int winClose(sqlite3_file *id){
 #ifndef SQLITE_OMIT_WAL
   assert( pFile->pShm==0 );
 #endif
-  OSTRACE(("CLOSE %d\n", pFile->h));
+  assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
+  OSTRACE(("CLOSE file=%p\n", pFile->h));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  rc = winUnmapfile(pFile);
+  if( rc!=SQLITE_OK ) return rc;
+#endif
+
   do{
     rc = osCloseHandle(pFile->h);
     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
@@ -2082,11 +2127,11 @@ static int winClose(sqlite3_file *id){
     sqlite3_free(pFile->zDeleteOnClose);
   }
 #endif
-  OSTRACE(("CLOSE %d %s\n", pFile->h, rc ? "ok" : "failed"));
   if( rc ){
     pFile->h = NULL;
   }
   OpenCounter(-1);
+  OSTRACE(("CLOSE file=%p, rc=%s\n", pFile->h, rc ? "ok" : "failed"));
   return rc ? SQLITE_OK
             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
                           "winClose", pFile->zPath);
@@ -2111,11 +2156,33 @@ static int winRead(
   int nRetry = 0;                 /* Number of retrys */
 
   assert( id!=0 );
+  assert( amt>0 );
+  assert( offset>=0 );
   SimulateIOError(return SQLITE_IOERR_READ);
-  OSTRACE(("READ %d lock=%d\n", pFile->h, pFile->locktype));
+  OSTRACE(("READ file=%p, buffer=%p, amount=%d, offset=%lld, lock=%d\n",
+           pFile->h, pBuf, amt, offset, pFile->locktype));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this read request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
+      OSTRACE(("READ-MMAP file=%p, rc=SQLITE_OK\n", pFile->h));
+      return SQLITE_OK;
+    }else{
+      int nCopy = (int)(pFile->mmapSize - offset);
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
 
 #if SQLITE_OS_WINCE
   if( seekWinFile(pFile, offset) ){
+    OSTRACE(("READ file=%p, rc=SQLITE_FULL\n", pFile->h));
     return SQLITE_FULL;
   }
   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
@@ -2129,6 +2196,7 @@ static int winRead(
     DWORD lastErrno;
     if( retryIoerr(&nRetry, &lastErrno) ) continue;
     pFile->lastErrno = lastErrno;
+    OSTRACE(("READ file=%p, rc=SQLITE_IOERR_READ\n", pFile->h));
     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
              "winRead", pFile->zPath);
   }
@@ -2136,9 +2204,11 @@ static int winRead(
   if( nRead<(DWORD)amt ){
     /* Unread parts of the buffer must be zero-filled */
     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
+    OSTRACE(("READ file=%p, rc=SQLITE_IOERR_SHORT_READ\n", pFile->h));
     return SQLITE_IOERR_SHORT_READ;
   }
 
+  OSTRACE(("READ file=%p, rc=SQLITE_OK\n", pFile->h));
   return SQLITE_OK;
 }
 
@@ -2152,7 +2222,7 @@ static int winWrite(
   int amt,                        /* Number of bytes to write */
   sqlite3_int64 offset            /* Offset into the file to begin writing at */
 ){
-  int rc = 0;                     /* True if error has occured, else false */
+  int rc = 0;                     /* True if error has occurred, else false */
   winFile *pFile = (winFile*)id;  /* File handle */
   int nRetry = 0;                 /* Number of retries */
 
@@ -2161,7 +2231,26 @@ static int winWrite(
   SimulateIOError(return SQLITE_IOERR_WRITE);
   SimulateDiskfullError(return SQLITE_FULL);
 
-  OSTRACE(("WRITE %d lock=%d\n", pFile->h, pFile->locktype));
+  OSTRACE(("WRITE file=%p, buffer=%p, amount=%d, offset=%lld, lock=%d\n",
+           pFile->h, pBuf, amt, offset, pFile->locktype));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this write request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
+      OSTRACE(("WRITE-MMAP file=%p, rc=SQLITE_OK\n", pFile->h));
+      return SQLITE_OK;
+    }else{
+      int nCopy = (int)(pFile->mmapSize - offset);
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
 
 #if SQLITE_OS_WINCE
   rc = seekWinFile(pFile, offset);
@@ -2214,13 +2303,16 @@ static int winWrite(
   if( rc ){
     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
        || ( pFile->lastErrno==ERROR_DISK_FULL )){
+      OSTRACE(("WRITE file=%p, rc=SQLITE_FULL\n", pFile->h));
       return SQLITE_FULL;
     }
+    OSTRACE(("WRITE file=%p, rc=SQLITE_IOERR_WRITE\n", pFile->h));
     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
              "winWrite", pFile->zPath);
   }else{
     logIoerr(nRetry);
   }
+  OSTRACE(("WRITE file=%p, rc=SQLITE_OK\n", pFile->h));
   return SQLITE_OK;
 }
 
@@ -2230,11 +2322,12 @@ static int winWrite(
 static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   winFile *pFile = (winFile*)id;  /* File handle object */
   int rc = SQLITE_OK;             /* Return code for this function */
+  DWORD lastErrno;
 
   assert( pFile );
-
-  OSTRACE(("TRUNCATE %d %lld\n", pFile->h, nByte));
   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
+  OSTRACE(("TRUNCATE file=%p, size=%lld, lock=%d\n",
+           pFile->h, nByte, pFile->locktype));
 
   /* If the user has configured a chunk-size for this file, truncate the
   ** file so that it consists of an integer number of chunks (i.e. the
@@ -2248,14 +2341,25 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
   if( seekWinFile(pFile, nByte) ){
     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
-             "winTruncate1", pFile->zPath);
-  }else if( 0==osSetEndOfFile(pFile->h) ){
-    pFile->lastErrno = osGetLastError();
+                     "winTruncate1", pFile->zPath);
+  }else if( 0==osSetEndOfFile(pFile->h) &&
+            ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
+    pFile->lastErrno = lastErrno;
     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
-             "winTruncate2", pFile->zPath);
+                     "winTruncate2", pFile->zPath);
   }
 
-  OSTRACE(("TRUNCATE %d %lld %s\n", pFile->h, nByte, rc ? "failed" : "ok"));
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* If the file was truncated to a size smaller than the currently
+  ** mapped region, reduce the effective mapping size as well. SQLite will
+  ** use read() and write() to access data beyond this point from now on.
+  */
+  if( pFile->pMapRegion && nByte<pFile->mmapSize ){
+    pFile->mmapSize = nByte;
+  }
+#endif
+
+  OSTRACE(("TRUNCATE file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -2295,13 +2399,14 @@ static int winSync(sqlite3_file *id, int flags){
       || (flags&0x0F)==SQLITE_SYNC_FULL
   );
 
-  OSTRACE(("SYNC %d lock=%d\n", pFile->h, pFile->locktype));
-
   /* Unix cannot, but some systems may return SQLITE_FULL from here. This
   ** line is to test that doing so does not cause any problems.
   */
   SimulateDiskfullError( return SQLITE_FULL );
 
+  OSTRACE(("SYNC file=%p, flags=%x, lock=%d\n",
+           pFile->h, flags, pFile->locktype));
+
 #ifndef SQLITE_TEST
   UNUSED_PARAMETER(flags);
 #else
@@ -2320,9 +2425,11 @@ static int winSync(sqlite3_file *id, int flags){
   rc = osFlushFileBuffers(pFile->h);
   SimulateIOError( rc=FALSE );
   if( rc ){
+    OSTRACE(("SYNC file=%p, rc=SQLITE_OK\n", pFile->h));
     return SQLITE_OK;
   }else{
     pFile->lastErrno = osGetLastError();
+    OSTRACE(("SYNC file=%p, rc=SQLITE_IOERR_FSYNC\n", pFile->h));
     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
              "winSync", pFile->zPath);
   }
@@ -2337,7 +2444,10 @@ static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
   int rc = SQLITE_OK;
 
   assert( id!=0 );
+  assert( pSize!=0 );
   SimulateIOError(return SQLITE_IOERR_FSTAT);
+  OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));
+
 #if SQLITE_OS_WINRT
   {
     FILE_STANDARD_INFO info;
@@ -2366,6 +2476,8 @@ static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
     }
   }
 #endif
+  OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",
+           pFile->h, pSize, *pSize, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -2407,6 +2519,7 @@ static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
 */
 static int getReadLock(winFile *pFile){
   int res;
+  OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
   if( isNT() ){
 #if SQLITE_OS_WINCE
     /*
@@ -2432,6 +2545,7 @@ static int getReadLock(winFile *pFile){
     pFile->lastErrno = osGetLastError();
     /* No need to log a failure to lock */
   }
+  OSTRACE(("READ-LOCK file=%p, rc=%s\n", pFile->h, sqlite3ErrName(res)));
   return res;
 }
 
@@ -2441,6 +2555,7 @@ static int getReadLock(winFile *pFile){
 static int unlockReadLock(winFile *pFile){
   int res;
   DWORD lastErrno;
+  OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
   if( isNT() ){
     res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
   }
@@ -2454,6 +2569,7 @@ static int unlockReadLock(winFile *pFile){
     winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
              "unlockReadLock", pFile->zPath);
   }
+  OSTRACE(("READ-UNLOCK file=%p, rc=%s\n", pFile->h, sqlite3ErrName(res)));
   return res;
 }
 
@@ -2492,14 +2608,15 @@ static int winLock(sqlite3_file *id, int locktype){
   DWORD lastErrno = NO_ERROR;
 
   assert( id!=0 );
-  OSTRACE(("LOCK %d %d was %d(%d)\n",
-           pFile->h, locktype, pFile->locktype, pFile->sharedLockByte));
+  OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
+           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
 
   /* If there is already a lock of this type or more restrictive on the
   ** OsFile, do nothing. Don't use the end_lock: exit path, as
   ** sqlite3OsEnterMutex() hasn't been called yet.
   */
   if( pFile->locktype>=locktype ){
+    OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));
     return SQLITE_OK;
   }
 
@@ -2527,7 +2644,8 @@ static int winLock(sqlite3_file *id, int locktype){
       ** If you are using this code as a model for alternative VFSes, do not
       ** copy this retry logic.  It is a hack intended for Windows only.
       */
-      OSTRACE(("could not get a PENDING lock. cnt=%d\n", cnt));
+      OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, rc=%s\n",
+               pFile->h, cnt, sqlite3ErrName(res)));
       if( cnt ) sqlite3_win32_sleep(1);
     }
     gotPendingLock = res;
@@ -2572,14 +2690,12 @@ static int winLock(sqlite3_file *id, int locktype){
   if( locktype==EXCLUSIVE_LOCK && res ){
     assert( pFile->locktype>=SHARED_LOCK );
     res = unlockReadLock(pFile);
-    OSTRACE(("unreadlock = %d\n", res));
     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
                       SHARED_SIZE, 0);
     if( res ){
       newLocktype = EXCLUSIVE_LOCK;
     }else{
       lastErrno = osGetLastError();
-      OSTRACE(("error-code = %d\n", lastErrno));
       getReadLock(pFile);
     }
   }
@@ -2597,12 +2713,14 @@ static int winLock(sqlite3_file *id, int locktype){
   if( res ){
     rc = SQLITE_OK;
   }else{
-    OSTRACE(("LOCK FAILED %d trying for %d but got %d\n", pFile->h,
-           locktype, newLocktype));
+    OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
+             pFile->h, locktype, newLocktype));
     pFile->lastErrno = lastErrno;
     rc = SQLITE_BUSY;
   }
   pFile->locktype = (u8)newLocktype;
+  OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
+           pFile->h, pFile->locktype, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -2616,20 +2734,23 @@ static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
   winFile *pFile = (winFile*)id;
 
   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
+  OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
 
   assert( id!=0 );
   if( pFile->locktype>=RESERVED_LOCK ){
     rc = 1;
-    OSTRACE(("TEST WR-LOCK %d %d (local)\n", pFile->h, rc));
+    OSTRACE(("TEST-WR-LOCK file=%p, rc=%d (local)\n", pFile->h, rc));
   }else{
-    rc = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);
+    rc = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE, 0, 1, 0);
     if( rc ){
       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
     }
     rc = !rc;
-    OSTRACE(("TEST WR-LOCK %d %d (remote)\n", pFile->h, rc));
+    OSTRACE(("TEST-WR-LOCK file=%p, rc=%d (remote)\n", pFile->h, rc));
   }
   *pResOut = rc;
+  OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
+           pFile->h, pResOut, *pResOut));
   return SQLITE_OK;
 }
 
@@ -2650,8 +2771,8 @@ static int winUnlock(sqlite3_file *id, int locktype){
   int rc = SQLITE_OK;
   assert( pFile!=0 );
   assert( locktype<=SHARED_LOCK );
-  OSTRACE(("UNLOCK %d to %d was %d(%d)\n", pFile->h, locktype,
-          pFile->locktype, pFile->sharedLockByte));
+  OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
+           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
   type = pFile->locktype;
   if( type>=EXCLUSIVE_LOCK ){
     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
@@ -2672,6 +2793,8 @@ static int winUnlock(sqlite3_file *id, int locktype){
     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
   }
   pFile->locktype = (u8)locktype;
+  OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
+           pFile->h, pFile->locktype, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -2699,17 +2822,21 @@ static int getTempname(int nBuf, char *zBuf);
 */
 static int winFileControl(sqlite3_file *id, int op, void *pArg){
   winFile *pFile = (winFile*)id;
+  OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
   switch( op ){
     case SQLITE_FCNTL_LOCKSTATE: {
       *(int*)pArg = pFile->locktype;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_LAST_ERRNO: {
       *(int*)pArg = (int)pFile->lastErrno;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_CHUNK_SIZE: {
       pFile->szChunk = *(int *)pArg;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_SIZE_HINT: {
@@ -2724,20 +2851,25 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
             SimulateIOErrorBenign(0);
           }
         }
+        OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
         return rc;
       }
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_PERSIST_WAL: {
       winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
       winModeBit(pFile, WINFILE_PSOW, (int*)pArg);
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_VFSNAME: {
       *(char**)pArg = sqlite3_mprintf("win32");
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_WIN32_AV_RETRY: {
@@ -2752,17 +2884,32 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
       }else{
         a[1] = win32IoerrRetryDelay;
       }
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_TEMPFILENAME: {
-      char *zTFile = sqlite3_malloc( pFile->pVfs->mxPathname );
+      char *zTFile = sqlite3MallocZero( pFile->pVfs->mxPathname );
       if( zTFile ){
         getTempname(pFile->pVfs->mxPathname, zTFile);
         *(char**)pArg = zTFile;
       }
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
+      return SQLITE_OK;
+    }
+#if SQLITE_MAX_MMAP_SIZE>0
+    case SQLITE_FCNTL_MMAP_SIZE: {
+      i64 newLimit = *(i64*)pArg;
+      if( newLimit>sqlite3GlobalConfig.mxMmap ){
+        newLimit = sqlite3GlobalConfig.mxMmap;
+      }
+      *(i64*)pArg = pFile->mmapSizeMax;
+      if( newLimit>=0 ) pFile->mmapSizeMax = newLimit;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
+#endif
   }
+  OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));
   return SQLITE_NOTFOUND;
 }
 
@@ -2790,8 +2937,6 @@ static int winDeviceCharacteristics(sqlite3_file *id){
          ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);
 }
 
-#ifndef SQLITE_OMIT_WAL
-
 /* 
 ** Windows will only let you create file view mappings
 ** on allocation size granularity boundaries.
@@ -2800,6 +2945,8 @@ static int winDeviceCharacteristics(sqlite3_file *id){
 */
 SYSTEM_INFO winSysInfo;
 
+#ifndef SQLITE_OMIT_WAL
+
 /*
 ** Helper functions to obtain and relinquish the global mutex. The
 ** global mutex is used to protect the winLockInfo objects used by 
@@ -2923,6 +3070,9 @@ static int winShmSystemLock(
   /* Access to the winShmNode object is serialized by the caller */
   assert( sqlite3_mutex_held(pFile->mutex) || pFile->nRef==0 );
 
+  OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
+           pFile->hFile.h, lockType, ofst, nByte));
+
   /* Release/Acquire the system-level lock */
   if( lockType==_SHM_UNLCK ){
     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
@@ -2940,11 +3090,9 @@ static int winShmSystemLock(
     rc = SQLITE_BUSY;
   }
 
-  OSTRACE(("SHM-LOCK %d %s %s 0x%08lx\n", 
-           pFile->hFile.h,
-           rc==SQLITE_OK ? "ok" : "failed",
-           lockType==_SHM_UNLCK ? "UnlockFileEx" : "LockFileEx",
-           pFile->lastErrno));
+  OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
+           pFile->hFile.h, (lockType == _SHM_UNLCK) ? "winUnlockFile" :
+           "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
 
   return rc;
 }
@@ -2964,6 +3112,8 @@ static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
   winShmNode *p;
   BOOL bRc;
   assert( winShmMutexHeld() );
+  OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
+           osGetCurrentProcessId(), deleteFlag));
   pp = &winShmNodeList;
   while( (p = *pp)!=0 ){
     if( p->nRef==0 ){
@@ -2971,15 +3121,13 @@ static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
       if( p->mutex ) sqlite3_mutex_free(p->mutex);
       for(i=0; i<p->nRegion; i++){
         bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
-        OSTRACE(("SHM-PURGE pid-%d unmap region=%d %s\n",
-                 (int)osGetCurrentProcessId(), i,
-                 bRc ? "ok" : "failed"));
+        OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
+                 osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
         bRc = osCloseHandle(p->aRegion[i].hMap);
-        OSTRACE(("SHM-PURGE pid-%d close region=%d %s\n",
-                 (int)osGetCurrentProcessId(), i,
-                 bRc ? "ok" : "failed"));
+        OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
+                 osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
       }
-      if( p->hFile.h != INVALID_HANDLE_VALUE ){
+      if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
         SimulateIOErrorBenign(1);
         winClose((sqlite3_file *)&p->hFile);
         SimulateIOErrorBenign(0);
@@ -3059,7 +3207,7 @@ static int winOpenSharedMemory(winFile *pDbFd){
     rc = winOpen(pDbFd->pVfs,
                  pShmNode->zFilename,             /* Name of the file (UTF-8) */
                  (sqlite3_file*)&pShmNode->hFile,  /* File handle here */
-                 SQLITE_OPEN_WAL | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, /* Mode flags */
+                 SQLITE_OPEN_WAL | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
                  0);
     if( SQLITE_OK!=rc ){
       goto shm_open_err;
@@ -3256,9 +3404,9 @@ static int winShmLock(
     }
   }
   sqlite3_mutex_leave(pShmNode->mutex);
-  OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x %s\n",
-           p->id, (int)osGetCurrentProcessId(), p->sharedMask, p->exclMask,
-           rc ? "failed" : "ok"));
+  OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",
+           osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,
+           sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -3379,8 +3527,8 @@ static int winShmMap(
           NULL, PAGE_READWRITE, 0, nByte, NULL
       );
 #endif
-      OSTRACE(("SHM-MAP pid-%d create region=%d nbyte=%d %s\n",
-               (int)osGetCurrentProcessId(), pShmNode->nRegion, nByte,
+      OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
+               osGetCurrentProcessId(), pShmNode->nRegion, nByte,
                hMap ? "ok" : "failed"));
       if( hMap ){
         int iOffset = pShmNode->nRegion*szRegion;
@@ -3394,8 +3542,8 @@ static int winShmMap(
             0, iOffset - iOffsetShift, szRegion + iOffsetShift
         );
 #endif
-        OSTRACE(("SHM-MAP pid-%d map region=%d offset=%d size=%d %s\n",
-                 (int)osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
+        OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
+                 osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
                  szRegion, pMap ? "ok" : "failed"));
       }
       if( !pMap ){
@@ -3433,6 +3581,230 @@ shmpage_out:
 #endif /* #ifndef SQLITE_OMIT_WAL */
 
 /*
+** Cleans up the mapped region of the specified file, if any.
+*/
+#if SQLITE_MAX_MMAP_SIZE>0
+static int winUnmapfile(winFile *pFile){
+  assert( pFile!=0 );
+  OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "
+           "mmapSize=%lld, mmapSizeActual=%lld, mmapSizeMax=%lld\n",
+           osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,
+           pFile->mmapSize, pFile->mmapSizeActual, pFile->mmapSizeMax));
+  if( pFile->pMapRegion ){
+    if( !osUnmapViewOfFile(pFile->pMapRegion) ){
+      pFile->lastErrno = osGetLastError();
+      OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "
+               "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,
+               pFile->pMapRegion));
+      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
+                         "winUnmap1", pFile->zPath);
+    }
+    pFile->pMapRegion = 0;
+    pFile->mmapSize = 0;
+    pFile->mmapSizeActual = 0;
+  }
+  if( pFile->hMap!=NULL ){
+    if( !osCloseHandle(pFile->hMap) ){
+      pFile->lastErrno = osGetLastError();
+      OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",
+               osGetCurrentProcessId(), pFile, pFile->hMap));
+      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
+                         "winUnmap2", pFile->zPath);
+    }
+    pFile->hMap = NULL;
+  }
+  OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile));
+  return SQLITE_OK;
+}
+
+/*
+** Memory map or remap the file opened by file-descriptor pFd (if the file
+** is already mapped, the existing mapping is replaced by the new). Or, if 
+** there already exists a mapping for this file, and there are still 
+** outstanding xFetch() references to it, this function is a no-op.
+**
+** If parameter nByte is non-negative, then it is the requested size of 
+** the mapping to create. Otherwise, if nByte is less than zero, then the 
+** requested size is the size of the file on disk. The actual size of the
+** created mapping is either the requested size or the value configured 
+** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
+**
+** SQLITE_OK is returned if no error occurs (even if the mapping is not
+** recreated as a result of outstanding references) or an SQLite error
+** code otherwise.
+*/
+static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
+  sqlite3_int64 nMap = nByte;
+  int rc;
+
+  assert( nMap>=0 || pFd->nFetchOut==0 );
+  OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",
+           osGetCurrentProcessId(), pFd, nByte));
+
+  if( pFd->nFetchOut>0 ) return SQLITE_OK;
+
+  if( nMap<0 ){
+    rc = winFileSize((sqlite3_file*)pFd, &nMap);
+    if( rc ){
+      OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",
+               osGetCurrentProcessId(), pFd));
+      return SQLITE_IOERR_FSTAT;
+    }
+  }
+  if( nMap>pFd->mmapSizeMax ){
+    nMap = pFd->mmapSizeMax;
+  }
+  nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
+ 
+  if( nMap==0 && pFd->mmapSize>0 ){
+    winUnmapfile(pFd);
+  }
+  if( nMap!=pFd->mmapSize ){
+    void *pNew = 0;
+    DWORD protect = PAGE_READONLY;
+    DWORD flags = FILE_MAP_READ;
+
+    winUnmapfile(pFd);
+    if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
+      protect = PAGE_READWRITE;
+      flags |= FILE_MAP_WRITE;
+    }
+#if SQLITE_OS_WINRT
+    pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
+#elif defined(SQLITE_WIN32_HAS_WIDE)
+    pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
+                                (DWORD)((nMap>>32) & 0xffffffff),
+                                (DWORD)(nMap & 0xffffffff), NULL);
+#elif defined(SQLITE_WIN32_HAS_ANSI)
+    pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
+                                (DWORD)((nMap>>32) & 0xffffffff),
+                                (DWORD)(nMap & 0xffffffff), NULL);
+#endif
+    if( pFd->hMap==NULL ){
+      pFd->lastErrno = osGetLastError();
+      rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
+                       "winMapfile", pFd->zPath);
+      /* Log the error, but continue normal operation using xRead/xWrite */
+      OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=SQLITE_IOERR_MMAP\n",
+               osGetCurrentProcessId(), pFd));
+      return SQLITE_OK;
+    }
+    assert( (nMap % winSysInfo.dwPageSize)==0 );
+#if SQLITE_OS_WINRT
+    pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, nMap);
+#else
+    assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
+    pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
+#endif
+    if( pNew==NULL ){
+      osCloseHandle(pFd->hMap);
+      pFd->hMap = NULL;
+      pFd->lastErrno = osGetLastError();
+      winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
+                  "winMapfile", pFd->zPath);
+      OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=SQLITE_IOERR_MMAP\n",
+               osGetCurrentProcessId(), pFd));
+      return SQLITE_OK;
+    }
+    pFd->pMapRegion = pNew;
+    pFd->mmapSize = nMap;
+    pFd->mmapSizeActual = nMap;
+  }
+
+  OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFd));
+  return SQLITE_OK;
+}
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+
+/*
+** If possible, return a pointer to a mapping of file fd starting at offset
+** iOff. The mapping must be valid for at least nAmt bytes.
+**
+** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
+** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
+** Finally, if an error does occur, return an SQLite error code. The final
+** value of *pp is undefined in this case.
+**
+** If this function does return a pointer, the caller must eventually 
+** release the reference by calling winUnfetch().
+*/
+static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
+#if SQLITE_MAX_MMAP_SIZE>0
+  winFile *pFd = (winFile*)fd;   /* The underlying database file */
+#endif
+  *pp = 0;
+
+  OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",
+           osGetCurrentProcessId(), fd, iOff, nAmt, pp));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFd->mmapSizeMax>0 ){
+    if( pFd->pMapRegion==0 ){
+      int rc = winMapfile(pFd, -1);
+      if( rc!=SQLITE_OK ){
+        OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",
+                 osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
+        return rc;
+      }
+    }
+    if( pFd->mmapSize >= iOff+nAmt ){
+      *pp = &((u8 *)pFd->pMapRegion)[iOff];
+      pFd->nFetchOut++;
+    }
+  }
+#endif
+
+  OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), fd, pp, *pp));
+  return SQLITE_OK;
+}
+
+/*
+** If the third argument is non-NULL, then this function releases a 
+** reference obtained by an earlier call to winFetch(). The second
+** argument passed to this function must be the same as the corresponding
+** argument that was passed to the winFetch() invocation. 
+**
+** Or, if the third argument is NULL, then this function is being called 
+** to inform the VFS layer that, according to POSIX, any existing mapping 
+** may now be invalid and should be unmapped.
+*/
+static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){
+#if SQLITE_MAX_MMAP_SIZE>0
+  winFile *pFd = (winFile*)fd;   /* The underlying database file */
+
+  /* If p==0 (unmap the entire file) then there must be no outstanding 
+  ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
+  ** then there must be at least one outstanding.  */
+  assert( (p==0)==(pFd->nFetchOut==0) );
+
+  /* If p!=0, it must match the iOff value. */
+  assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
+
+  OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",
+           osGetCurrentProcessId(), pFd, iOff, p));
+
+  if( p ){
+    pFd->nFetchOut--;
+  }else{
+    /* FIXME:  If Windows truly always prevents truncating or deleting a
+    ** file while a mapping is held, then the following winUnmapfile() call
+    ** is unnecessary can can be omitted - potentially improving
+    ** performance.  */
+    winUnmapfile(pFd);
+  }
+
+  assert( pFd->nFetchOut>=0 );
+#endif
+
+  OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), fd));
+  return SQLITE_OK;
+}
+
+/*
 ** Here ends the implementation of all sqlite3_file methods.
 **
 ********************** End sqlite3_file Methods *******************************
@@ -3443,7 +3815,7 @@ shmpage_out:
 ** sqlite3_file for win32.
 */
 static const sqlite3_io_methods winIoMethod = {
-  2,                              /* iVersion */
+  3,                              /* iVersion */
   winClose,                       /* xClose */
   winRead,                        /* xRead */
   winWrite,                       /* xWrite */
@@ -3459,7 +3831,9 @@ static const sqlite3_io_methods winIoMethod = {
   winShmMap,                      /* xShmMap */
   winShmLock,                     /* xShmLock */
   winShmBarrier,                  /* xShmBarrier */
-  winShmUnmap                     /* xShmUnmap */
+  winShmUnmap,                    /* xShmUnmap */
+  winFetch,                       /* xFetch */
+  winUnfetch                      /* xUnfetch */
 };
 
 /****************************************************************************
@@ -3523,6 +3897,7 @@ static int getTempname(int nBuf, char *zBuf){
       sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zMulti);
       sqlite3_free(zMulti);
     }else{
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
       return SQLITE_IOERR_NOMEM;
     }
   }
@@ -3536,6 +3911,7 @@ static int getTempname(int nBuf, char *zBuf){
       sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zUtf8);
       sqlite3_free(zUtf8);
     }else{
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
       return SQLITE_IOERR_NOMEM;
     }
   }
@@ -3548,6 +3924,7 @@ static int getTempname(int nBuf, char *zBuf){
   nTempPath = sqlite3Strlen30(zTempPath);
 
   if( (nTempPath + sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX) + 18) >= nBuf ){
+    OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
     return SQLITE_ERROR;
   }
 
@@ -3565,8 +3942,8 @@ static int getTempname(int nBuf, char *zBuf){
   zBuf[j] = 0;
   zBuf[j+1] = 0;
 
-  OSTRACE(("TEMP FILENAME: %s\n", zBuf));
-  return SQLITE_OK; 
+  OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
+  return SQLITE_OK;
 }
 
 /*
@@ -3635,9 +4012,7 @@ static int winOpen(
   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
   int isCreate     = (flags & SQLITE_OPEN_CREATE);
-#ifndef NDEBUG
   int isReadonly   = (flags & SQLITE_OPEN_READONLY);
-#endif
   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
 
 #ifndef NDEBUG
@@ -3648,6 +4023,9 @@ static int winOpen(
   ));
 #endif
 
+  OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
+           zUtf8Name, id, flags, pOutFlags));
+
   /* Check the following statements are true: 
   **
   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and 
@@ -3674,8 +4052,9 @@ static int winOpen(
        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
   );
 
-  assert( id!=0 );
-  UNUSED_PARAMETER(pVfs);
+  assert( pFile!=0 );
+  memset(pFile, 0, sizeof(winFile));
+  pFile->h = INVALID_HANDLE_VALUE;
 
 #if SQLITE_OS_WINRT
   if( !sqlite3_temp_directory ){
@@ -3684,15 +4063,15 @@ static int winOpen(
   }
 #endif
 
-  pFile->h = INVALID_HANDLE_VALUE;
-
   /* If the second argument to this function is NULL, generate a 
   ** temporary file name to use 
   */
   if( !zUtf8Name ){
     assert(isDelete && !isOpenJournal);
+    memset(zTmpname, 0, MAX_PATH+2);
     rc = getTempname(MAX_PATH+2, zTmpname);
     if( rc!=SQLITE_OK ){
+      OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
       return rc;
     }
     zUtf8Name = zTmpname;
@@ -3708,11 +4087,13 @@ static int winOpen(
   /* Convert the filename to the system encoding. */
   zConverted = convertUtf8Filename(zUtf8Name);
   if( zConverted==0 ){
+    OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
     return SQLITE_IOERR_NOMEM;
   }
 
   if( winIsDir(zConverted) ){
     sqlite3_free(zConverted);
+    OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
     return SQLITE_CANTOPEN_ISDIR;
   }
 
@@ -3803,9 +4184,8 @@ static int winOpen(
 #endif
   logIoerr(cnt);
 
-  OSTRACE(("OPEN %d %s 0x%lx %s\n", 
-           h, zName, dwDesiredAccess, 
-           h==INVALID_HANDLE_VALUE ? "failed" : "ok"));
+  OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
+           dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
 
   if( h==INVALID_HANDLE_VALUE ){
     pFile->lastErrno = lastErrno;
@@ -3813,7 +4193,9 @@ static int winOpen(
     sqlite3_free(zConverted);
     if( isReadWrite && !isExclusive ){
       return winOpen(pVfs, zName, id, 
-             ((flags|SQLITE_OPEN_READONLY)&~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)), pOutFlags);
+         ((flags|SQLITE_OPEN_READONLY) &
+                     ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
+         pOutFlags);
     }else{
       return SQLITE_CANTOPEN_BKPT;
     }
@@ -3827,26 +4209,18 @@ static int winOpen(
     }
   }
 
-  memset(pFile, 0, sizeof(*pFile));
-  pFile->pMethod = &winIoMethod;
-  pFile->h = h;
-  pFile->lastErrno = NO_ERROR;
-  pFile->pVfs = pVfs;
-#ifndef SQLITE_OMIT_WAL
-  pFile->pShm = 0;
-#endif
-  pFile->zPath = zName;
-  if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
-    pFile->ctrlFlags |= WINFILE_PSOW;
-  }
+  OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "
+           "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
+           *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
 
 #if SQLITE_OS_WINCE
   if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
-       && !winceCreateLock(zName, pFile)
+       && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
   ){
     osCloseHandle(h);
     sqlite3_free(zConverted);
-    return SQLITE_CANTOPEN_BKPT;
+    OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
+    return rc;
   }
   if( isTemp ){
     pFile->zDeleteOnClose = zConverted;
@@ -3856,6 +4230,25 @@ static int winOpen(
     sqlite3_free(zConverted);
   }
 
+  pFile->pMethod = &winIoMethod;
+  pFile->pVfs = pVfs;
+  pFile->h = h;
+  if( isReadonly ){
+    pFile->ctrlFlags |= WINFILE_RDONLY;
+  }
+  if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
+    pFile->ctrlFlags |= WINFILE_PSOW;
+  }
+  pFile->lastErrno = NO_ERROR;
+  pFile->zPath = zName;
+#if SQLITE_MAX_MMAP_SIZE>0
+  pFile->hMap = NULL;
+  pFile->pMapRegion = 0;
+  pFile->mmapSize = 0;
+  pFile->mmapSizeActual = 0;
+  pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;
+#endif
+
   OpenCounter(+1);
   return rc;
 }
@@ -3886,6 +4279,8 @@ static int winDelete(
   UNUSED_PARAMETER(syncDir);
 
   SimulateIOError(return SQLITE_IOERR_DELETE);
+  OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));
+
   zConverted = convertUtf8Filename(zFilename);
   if( zConverted==0 ){
     return SQLITE_IOERR_NOMEM;
@@ -3900,7 +4295,8 @@ static int winDelete(
         attr = sAttrData.dwFileAttributes;
       }else{
         lastErrno = osGetLastError();
-        if( lastErrno==ERROR_FILE_NOT_FOUND || lastErrno==ERROR_PATH_NOT_FOUND ){
+        if( lastErrno==ERROR_FILE_NOT_FOUND
+         || lastErrno==ERROR_PATH_NOT_FOUND ){
           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
         }else{
           rc = SQLITE_ERROR;
@@ -3912,7 +4308,8 @@ static int winDelete(
 #endif
       if ( attr==INVALID_FILE_ATTRIBUTES ){
         lastErrno = osGetLastError();
-        if( lastErrno==ERROR_FILE_NOT_FOUND || lastErrno==ERROR_PATH_NOT_FOUND ){
+        if( lastErrno==ERROR_FILE_NOT_FOUND
+         || lastErrno==ERROR_PATH_NOT_FOUND ){
           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
         }else{
           rc = SQLITE_ERROR;
@@ -3939,7 +4336,8 @@ static int winDelete(
       attr = osGetFileAttributesA(zConverted);
       if ( attr==INVALID_FILE_ATTRIBUTES ){
         lastErrno = osGetLastError();
-        if( lastErrno==ERROR_FILE_NOT_FOUND || lastErrno==ERROR_PATH_NOT_FOUND ){
+        if( lastErrno==ERROR_FILE_NOT_FOUND
+         || lastErrno==ERROR_PATH_NOT_FOUND ){
           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
         }else{
           rc = SQLITE_ERROR;
@@ -3968,12 +4366,12 @@ static int winDelete(
     logIoerr(cnt);
   }
   sqlite3_free(zConverted);
-  OSTRACE(("DELETE \"%s\" %s\n", zFilename, (rc ? "failed" : "ok" )));
+  OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
   return rc;
 }
 
 /*
-** Check the existance and status of a file.
+** Check the existence and status of a file.
 */
 static int winAccess(
   sqlite3_vfs *pVfs,         /* Not used on win32 */
@@ -3988,8 +4386,12 @@ static int winAccess(
   UNUSED_PARAMETER(pVfs);
 
   SimulateIOError( return SQLITE_IOERR_ACCESS; );
+  OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
+           zFilename, flags, pResOut));
+
   zConverted = convertUtf8Filename(zFilename);
   if( zConverted==0 ){
+    OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
     return SQLITE_IOERR_NOMEM;
   }
   if( isNT() ){
@@ -4040,6 +4442,8 @@ static int winAccess(
       assert(!"Invalid flags argument");
   }
   *pResOut = rc;
+  OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
+           zFilename, pResOut, *pResOut));
   return SQLITE_OK;
 }
 
@@ -4107,16 +4511,12 @@ static int winFullPathname(
     */
     char zOut[MAX_PATH+1];
     memset(zOut, 0, MAX_PATH+1);
-    cygwin_conv_to_win32_path(zRelative, zOut); /* POSIX to Win32 */
+    cygwin_conv_path(CCP_POSIX_TO_WIN_A|CCP_RELATIVE, zRelative, zOut,
+                     MAX_PATH+1);
     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s\\%s",
                      sqlite3_data_directory, zOut);
   }else{
-    /*
-    ** NOTE: The Cygwin docs state that the maximum length needed
-    **       for the buffer passed to cygwin_conv_to_full_win32_path
-    **       is MAX_PATH.
-    */
-    cygwin_conv_to_full_win32_path(zRelative, zFull);
+    cygwin_conv_path(CCP_POSIX_TO_WIN_A, zRelative, zFull, nFull);
   }
   return SQLITE_OK;
 #endif
@@ -4274,9 +4674,9 @@ static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
   UNUSED_PARAMETER(pVfs);
   getLastErrorMsg(osGetLastError(), nBuf, zBufOut);
 }
-static void (*winDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol))(void){
+static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
   UNUSED_PARAMETER(pVfs);
-  return (void(*)(void))osGetProcAddressA((HANDLE)pHandle, zSymbol);
+  return (void(*)(void))osGetProcAddressA((HANDLE)pH, zSym);
 }
 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
   UNUSED_PARAMETER(pVfs);
@@ -4374,7 +4774,8 @@ static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
 #endif
   /* 2^32 - to avoid use of LL and warnings in gcc */
   static const sqlite3_int64 max32BitValue = 
-      (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 + (sqlite3_int64)294967296;
+      (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +
+      (sqlite3_int64)294967296;
 
 #if SQLITE_OS_WINCE
   SYSTEMTIME time;
@@ -4483,7 +4884,6 @@ int sqlite3_os_init(void){
   ** correctly.  See ticket [bb3a86e890c8e96ab] */
   assert( ArraySize(aSyscall)==74 );
 
-#ifndef SQLITE_OMIT_WAL
   /* get memory map allocation granularity */
   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
 #if SQLITE_OS_WINRT
@@ -4491,8 +4891,8 @@ int sqlite3_os_init(void){
 #else
   osGetSystemInfo(&winSysInfo);
 #endif
-  assert(winSysInfo.dwAllocationGranularity > 0);
-#endif
+  assert( winSysInfo.dwAllocationGranularity>0 );
+  assert( winSysInfo.dwPageSize>0 );
 
   sqlite3_vfs_register(&winVfs, 1);
   return SQLITE_OK; 
diff --git a/lib/libsqlite3/src/pager.c b/lib/libsqlite3/src/pager.c
index 5879cf760af..1c6a84fea4b 100644
--- a/lib/libsqlite3/src/pager.c
+++ b/lib/libsqlite3/src/pager.c
@@ -273,7 +273,7 @@ int sqlite3PagerTrace=1;  /* True to enable tracing */
 **    * A write transaction is active.
 **    * An EXCLUSIVE or greater lock is held on the database file.
 **    * All writing and syncing of journal and database data has finished.
-**      If no error occured, all that remains is to finalize the journal to
+**      If no error occurred, all that remains is to finalize the journal to
 **      commit the transaction. If an error did occur, the caller will need
 **      to rollback the transaction. 
 **
@@ -521,7 +521,7 @@ struct PagerSavepoint {
 **
 ** doNotSpill, doNotSyncSpill
 **
-**   These two boolean variables control the behaviour of cache-spills
+**   These two boolean variables control the behavior of cache-spills
 **   (calls made by the pcache module to the pagerStress() routine to
 **   write cached data to the file-system in order to free up memory).
 **
@@ -655,6 +655,11 @@ struct Pager {
   PagerSavepoint *aSavepoint; /* Array of active savepoints */
   int nSavepoint;             /* Number of elements in aSavepoint[] */
   char dbFileVers[16];        /* Changes whenever database file changes */
+
+  u8 bUseFetch;               /* True to use xFetch() */
+  int nMmapOut;               /* Number of mmap pages currently outstanding */
+  sqlite3_int64 szMmap;       /* Desired maximum mmap size */
+  PgHdr *pMmapFreelist;       /* List of free mmap page headers (pDirty) */
   /*
   ** End of the routinely-changing class members
   ***************************************************************************/
@@ -766,6 +771,16 @@ static const unsigned char aJournalMagic[] = {
 #endif
 
 /*
+** The macro USEFETCH is true if we are allowed to use the xFetch and xUnfetch
+** interfaces to access the database using memory-mapped I/O.
+*/
+#if SQLITE_MAX_MMAP_SIZE>0
+# define USEFETCH(x) ((x)->bUseFetch)
+#else
+# define USEFETCH(x) 0
+#endif
+
+/*
 ** The maximum legal page number is (2^31 - 1).
 */
 #define PAGER_MAX_PGNO 2147483647
@@ -1399,7 +1414,7 @@ static int writeJournalHdr(Pager *pPager){
     memset(zHeader, 0, sizeof(aJournalMagic)+4);
   }
 
-  /* The random check-hash initialiser */ 
+  /* The random check-hash initializer */ 
   sqlite3_randomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
   put32bits(&zHeader[sizeof(aJournalMagic)+4], pPager->cksumInit);
   /* The initial database size */
@@ -1838,6 +1853,8 @@ static int pager_error(Pager *pPager, int rc){
   return rc;
 }
 
+static int pager_truncate(Pager *pPager, Pgno nPage);
+
 /*
 ** This routine ends a transaction. A transaction is usually ended by 
 ** either a COMMIT or a ROLLBACK operation. This routine may be called 
@@ -1891,7 +1908,7 @@ static int pager_error(Pager *pPager, int rc){
 ** to the first error encountered (the journal finalization one) is
 ** returned.
 */
-static int pager_end_transaction(Pager *pPager, int hasMaster){
+static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
   int rc = SQLITE_OK;      /* Error code from journal finalization operation */
   int rc2 = SQLITE_OK;     /* Error code from db file unlock operation */
 
@@ -1977,7 +1994,17 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
     */
     rc2 = sqlite3WalEndWriteTransaction(pPager->pWal);
     assert( rc2==SQLITE_OK );
+  }else if( rc==SQLITE_OK && bCommit && pPager->dbFileSize>pPager->dbSize ){
+    /* This branch is taken when committing a transaction in rollback-journal
+    ** mode if the database file on disk is larger than the database image.
+    ** At this point the journal has been finalized and the transaction 
+    ** successfully committed, but the EXCLUSIVE lock is still held on the
+    ** file. So it is safe to truncate the database file to its minimum
+    ** required size.  */
+    assert( pPager->eLock==EXCLUSIVE_LOCK );
+    rc = pager_truncate(pPager, pPager->dbSize);
   }
+
   if( !pPager->exclusiveMode 
    && (!pagerUseWal(pPager) || sqlite3WalExclusiveMode(pPager->pWal, 0))
   ){
@@ -2016,7 +2043,7 @@ static void pagerUnlockAndRollback(Pager *pPager){
       sqlite3EndBenignMalloc();
     }else if( !pPager->exclusiveMode ){
       assert( pPager->eState==PAGER_READER );
-      pager_end_transaction(pPager, 0);
+      pager_end_transaction(pPager, 0, 0);
     }
   }
   pager_unlock(pPager);
@@ -2240,7 +2267,7 @@ static int pager_playback_one_page(
     i64 ofst = (pgno-1)*(i64)pPager->pageSize;
     testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
     assert( !pagerUseWal(pPager) );
-    rc = sqlite3OsWrite(pPager->fd, (u8*)aData, pPager->pageSize, ofst);
+    rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);
     if( pgno>pPager->dbFileSize ){
       pPager->dbFileSize = pgno;
     }
@@ -2631,6 +2658,7 @@ static int pager_playback(Pager *pPager, int isHot){
   int res = 1;             /* Value returned by sqlite3OsAccess() */
   char *zMaster = 0;       /* Name of master journal file if any */
   int needPagerReset;      /* True to reset page prior to first page rollback */
+  int nPlayback = 0;       /* Total number of pages restored from journal */
 
   /* Figure out how many records are in the journal.  Abort early if
   ** the journal is empty.
@@ -2731,7 +2759,9 @@ static int pager_playback(Pager *pPager, int isHot){
         needPagerReset = 0;
       }
       rc = pager_playback_one_page(pPager,&pPager->journalOff,0,1,0);
-      if( rc!=SQLITE_OK ){
+      if( rc==SQLITE_OK ){
+        nPlayback++;
+      }else{
         if( rc==SQLITE_DONE ){
           pPager->journalOff = szJ;
           break;
@@ -2791,7 +2821,7 @@ end_playback:
     rc = sqlite3PagerSync(pPager);
   }
   if( rc==SQLITE_OK ){
-    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
+    rc = pager_end_transaction(pPager, zMaster[0]!='\0', 0);
     testcase( rc!=SQLITE_OK );
   }
   if( rc==SQLITE_OK && zMaster[0] && res ){
@@ -2801,6 +2831,10 @@ end_playback:
     rc = pager_delmaster(pPager, zMaster);
     testcase( rc!=SQLITE_OK );
   }
+  if( isHot && nPlayback ){
+    sqlite3_log(SQLITE_NOTICE_RECOVER_ROLLBACK, "recovered %d pages from %s",
+                nPlayback, pPager->zJournal);
+  }
 
   /* The Pager.sectorSize variable may have been updated while rolling
   ** back a journal created by a process with a different sector size
@@ -2822,11 +2856,10 @@ end_playback:
 ** If an IO error occurs, then the IO error is returned to the caller.
 ** Otherwise, SQLITE_OK is returned.
 */
-static int readDbPage(PgHdr *pPg){
+static int readDbPage(PgHdr *pPg, u32 iFrame){
   Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
   Pgno pgno = pPg->pgno;       /* Page number to read */
   int rc = SQLITE_OK;          /* Return code */
-  int isInWal = 0;             /* True if page is in log file */
   int pgsz = pPager->pageSize; /* Number of bytes to read */
 
   assert( pPager->eState>=PAGER_READER && !MEMDB );
@@ -2838,11 +2871,13 @@ static int readDbPage(PgHdr *pPg){
     return SQLITE_OK;
   }
 
-  if( pagerUseWal(pPager) ){
+#ifndef SQLITE_OMIT_WAL
+  if( iFrame ){
     /* Try to pull the page from the write-ahead log. */
-    rc = sqlite3WalRead(pPager->pWal, pgno, &isInWal, pgsz, pPg->pData);
-  }
-  if( rc==SQLITE_OK && !isInWal ){
+    rc = sqlite3WalReadFrame(pPager->pWal, iFrame, pgsz, pPg->pData);
+  }else
+#endif
+  {
     i64 iOffset = (pgno-1)*(i64)pPager->pageSize;
     rc = sqlite3OsRead(pPager->fd, pPg->pData, pgsz, iOffset);
     if( rc==SQLITE_IOERR_SHORT_READ ){
@@ -2921,12 +2956,17 @@ static int pagerUndoCallback(void *pCtx, Pgno iPg){
   Pager *pPager = (Pager *)pCtx;
   PgHdr *pPg;
 
+  assert( pagerUseWal(pPager) );
   pPg = sqlite3PagerLookup(pPager, iPg);
   if( pPg ){
     if( sqlite3PcachePageRefcount(pPg)==1 ){
       sqlite3PcacheDrop(pPg);
     }else{
-      rc = readDbPage(pPg);
+      u32 iFrame = 0;
+      rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);
+      if( rc==SQLITE_OK ){
+        rc = readDbPage(pPg, iFrame);
+      }
       if( rc==SQLITE_OK ){
         pPager->xReiniter(pPg);
       }
@@ -3070,6 +3110,7 @@ static int pagerBeginReadTransaction(Pager *pPager){
   rc = sqlite3WalBeginReadTransaction(pPager->pWal, &changed);
   if( rc!=SQLITE_OK || changed ){
     pager_reset(pPager);
+    if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
   }
 
   return rc;
@@ -3332,6 +3373,29 @@ void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
 }
 
 /*
+** Invoke SQLITE_FCNTL_MMAP_SIZE based on the current value of szMmap.
+*/
+static void pagerFixMaplimit(Pager *pPager){
+#if SQLITE_MAX_MMAP_SIZE>0
+  sqlite3_file *fd = pPager->fd;
+  if( isOpen(fd) ){
+    sqlite3_int64 sz;
+    pPager->bUseFetch = (fd->pMethods->iVersion>=3) && pPager->szMmap>0;
+    sz = pPager->szMmap;
+    sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_MMAP_SIZE, &sz);
+  }
+#endif
+}
+
+/*
+** Change the maximum size of any memory mapping made of the database file.
+*/
+void sqlite3PagerSetMmapLimit(Pager *pPager, sqlite3_int64 szMmap){
+  pPager->szMmap = szMmap;
+  pagerFixMaplimit(pPager);
+}
+
+/*
 ** Free as much memory as possible from the pager.
 */
 void sqlite3PagerShrink(Pager *pPager){
@@ -3566,6 +3630,7 @@ int sqlite3PagerSetPagesize(Pager *pPager, u32 *pPageSize, int nReserve){
     assert( nReserve>=0 && nReserve<1000 );
     pPager->nReserve = (i16)nReserve;
     pagerReportSize(pPager);
+    pagerFixMaplimit(pPager);
   }
   return rc;
 }
@@ -3719,7 +3784,7 @@ static int pager_wait_on_lock(Pager *pPager, int locktype){
 ** dirty page were to be discarded from the cache via the pagerStress()
 ** routine, pagerStress() would not write the current page content to
 ** the database file. If a savepoint transaction were rolled back after
-** this happened, the correct behaviour would be to restore the current
+** this happened, the correct behavior would be to restore the current
 ** content of the page. However, since this content is not present in either
 ** the database file or the portion of the rollback journal and 
 ** sub-journal rolled back the content could not be restored and the
@@ -3743,12 +3808,26 @@ static void assertTruncateConstraint(Pager *pPager){
 ** function does not actually modify the database file on disk. It 
 ** just sets the internal state of the pager object so that the 
 ** truncation will be done when the current transaction is committed.
+**
+** This function is only called right before committing a transaction.
+** Once this function has been called, the transaction must either be
+** rolled back or committed. It is not safe to call this function and
+** then continue writing to the database.
 */
 void sqlite3PagerTruncateImage(Pager *pPager, Pgno nPage){
   assert( pPager->dbSize>=nPage );
   assert( pPager->eState>=PAGER_WRITER_CACHEMOD );
   pPager->dbSize = nPage;
-  assertTruncateConstraint(pPager);
+
+  /* At one point the code here called assertTruncateConstraint() to
+  ** ensure that all pages being truncated away by this operation are,
+  ** if one or more savepoints are open, present in the savepoint 
+  ** journal so that they can be restored if the savepoint is rolled
+  ** back. This is no longer necessary as this function is now only
+  ** called right before committing a transaction. So although the 
+  ** Pager object may still have open savepoints (Pager.nSavepoint!=0), 
+  ** they cannot be rolled back. So the assertTruncateConstraint() call
+  ** is no longer correct. */
 }
 
 
@@ -3778,6 +3857,81 @@ static int pagerSyncHotJournal(Pager *pPager){
 }
 
 /*
+** Obtain a reference to a memory mapped page object for page number pgno. 
+** The new object will use the pointer pData, obtained from xFetch().
+** If successful, set *ppPage to point to the new page reference
+** and return SQLITE_OK. Otherwise, return an SQLite error code and set
+** *ppPage to zero.
+**
+** Page references obtained by calling this function should be released
+** by calling pagerReleaseMapPage().
+*/
+static int pagerAcquireMapPage(
+  Pager *pPager,                  /* Pager object */
+  Pgno pgno,                      /* Page number */
+  void *pData,                    /* xFetch()'d data for this page */
+  PgHdr **ppPage                  /* OUT: Acquired page object */
+){
+  PgHdr *p;                       /* Memory mapped page to return */
+
+  if( pPager->pMmapFreelist ){
+    *ppPage = p = pPager->pMmapFreelist;
+    pPager->pMmapFreelist = p->pDirty;
+    p->pDirty = 0;
+    memset(p->pExtra, 0, pPager->nExtra);
+  }else{
+    *ppPage = p = (PgHdr *)sqlite3MallocZero(sizeof(PgHdr) + pPager->nExtra);
+    if( p==0 ){
+      sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1) * pPager->pageSize, pData);
+      return SQLITE_NOMEM;
+    }
+    p->pExtra = (void *)&p[1];
+    p->flags = PGHDR_MMAP;
+    p->nRef = 1;
+    p->pPager = pPager;
+  }
+
+  assert( p->pExtra==(void *)&p[1] );
+  assert( p->pPage==0 );
+  assert( p->flags==PGHDR_MMAP );
+  assert( p->pPager==pPager );
+  assert( p->nRef==1 );
+
+  p->pgno = pgno;
+  p->pData = pData;
+  pPager->nMmapOut++;
+
+  return SQLITE_OK;
+}
+
+/*
+** Release a reference to page pPg. pPg must have been returned by an 
+** earlier call to pagerAcquireMapPage().
+*/
+static void pagerReleaseMapPage(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  pPager->nMmapOut--;
+  pPg->pDirty = pPager->pMmapFreelist;
+  pPager->pMmapFreelist = pPg;
+
+  assert( pPager->fd->pMethods->iVersion>=3 );
+  sqlite3OsUnfetch(pPager->fd, (i64)(pPg->pgno-1)*pPager->pageSize, pPg->pData);
+}
+
+/*
+** Free all PgHdr objects stored in the Pager.pMmapFreelist list.
+*/
+static void pagerFreeMapHdrs(Pager *pPager){
+  PgHdr *p;
+  PgHdr *pNext;
+  for(p=pPager->pMmapFreelist; p; p=pNext){
+    pNext = p->pDirty;
+    sqlite3_free(p);
+  }
+}
+
+
+/*
 ** Shutdown the page cache.  Free all memory and close all files.
 **
 ** If a transaction was in progress when this routine is called, that
@@ -3797,6 +3951,7 @@ int sqlite3PagerClose(Pager *pPager){
   assert( assert_pager_state(pPager) );
   disable_simulated_io_errors();
   sqlite3BeginBenignMalloc();
+  pagerFreeMapHdrs(pPager);
   /* pPager->errCode = 0; */
   pPager->exclusiveMode = 0;
 #ifndef SQLITE_OMIT_WAL
@@ -4058,7 +4213,9 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
   ** file size will be.
   */
   assert( rc!=SQLITE_OK || isOpen(pPager->fd) );
-  if( rc==SQLITE_OK && pPager->dbSize>pPager->dbHintSize ){
+  if( rc==SQLITE_OK 
+   && (pList->pDirty ? pPager->dbSize : pList->pgno+1)>pPager->dbHintSize 
+  ){
     sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
     sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
     pPager->dbHintSize = pPager->dbSize;
@@ -4612,6 +4769,7 @@ int sqlite3PagerOpen(
   /* pPager->pBusyHandlerArg = 0; */
   pPager->xReiniter = xReinit;
   /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
+  /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */
 
   *ppPager = pPager;
   return SQLITE_OK;
@@ -4801,6 +4959,11 @@ int sqlite3PagerSharedLock(Pager *pPager){
       goto failed;
     }
     if( bHotJournal ){
+      if( pPager->readOnly ){
+        rc = SQLITE_READONLY_ROLLBACK;
+        goto failed;
+      }
+
       /* Get an EXCLUSIVE lock on the database file. At this point it is
       ** important that a RESERVED lock is not obtained on the way to the
       ** EXCLUSIVE lock. If it were, another process might open the
@@ -4898,9 +5061,11 @@ int sqlite3PagerSharedLock(Pager *pPager){
       );
     }
 
-    if( !pPager->tempFile 
-     && (pPager->pBackup || sqlite3PcachePagecount(pPager->pPCache)>0) 
-    ){
+    if( !pPager->tempFile && (
+        pPager->pBackup 
+     || sqlite3PcachePagecount(pPager->pPCache)>0 
+     || USEFETCH(pPager)
+    )){
       /* The shared-lock has just been acquired on the database file
       ** and there are already pages in the cache (from a previous
       ** read or write transaction).  Check to see if the database
@@ -4926,7 +5091,7 @@ int sqlite3PagerSharedLock(Pager *pPager){
       if( nPage>0 ){
         IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
         rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
-        if( rc!=SQLITE_OK ){
+        if( rc!=SQLITE_OK && rc!=SQLITE_IOERR_SHORT_READ ){
           goto failed;
         }
       }else{
@@ -4935,6 +5100,16 @@ int sqlite3PagerSharedLock(Pager *pPager){
 
       if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
         pager_reset(pPager);
+
+        /* Unmap the database file. It is possible that external processes
+        ** may have truncated the database file and then extended it back
+        ** to its original size while this process was not holding a lock.
+        ** In this case there may exist a Pager.pMap mapping that appears
+        ** to be the right size but is not actually valid. Avoid this
+        ** possibility by unmapping the db here. */
+        if( USEFETCH(pPager) ){
+          sqlite3OsUnfetch(pPager->fd, 0, 0);
+        }
       }
     }
 
@@ -4976,7 +5151,7 @@ int sqlite3PagerSharedLock(Pager *pPager){
 ** nothing to rollback, so this routine is a no-op.
 */ 
 static void pagerUnlockIfUnused(Pager *pPager){
-  if( (sqlite3PcacheRefCount(pPager->pPCache)==0) ){
+  if( pPager->nMmapOut==0 && (sqlite3PcacheRefCount(pPager->pPCache)==0) ){
     pagerUnlockAndRollback(pPager);
   }
 }
@@ -5035,13 +5210,27 @@ int sqlite3PagerAcquire(
   Pager *pPager,      /* The pager open on the database file */
   Pgno pgno,          /* Page number to fetch */
   DbPage **ppPage,    /* Write a pointer to the page here */
-  int noContent       /* Do not bother reading content from disk if true */
+  int flags           /* PAGER_ACQUIRE_XXX flags */
 ){
-  int rc;
-  PgHdr *pPg;
+  int rc = SQLITE_OK;
+  PgHdr *pPg = 0;
+  u32 iFrame = 0;                 /* Frame to read from WAL file */
+  const int noContent = (flags & PAGER_ACQUIRE_NOCONTENT);
+
+  /* It is acceptable to use a read-only (mmap) page for any page except
+  ** page 1 if there is no write-transaction open or the ACQUIRE_READONLY
+  ** flag was specified by the caller. And so long as the db is not a 
+  ** temporary or in-memory database.  */
+  const int bMmapOk = (pgno!=1 && USEFETCH(pPager)
+   && (pPager->eState==PAGER_READER || (flags & PAGER_ACQUIRE_READONLY))
+#ifdef SQLITE_HAS_CODEC
+   && pPager->xCodec==0
+#endif
+  );
 
   assert( pPager->eState>=PAGER_READER );
   assert( assert_pager_state(pPager) );
+  assert( noContent==0 || bMmapOk==0 );
 
   if( pgno==0 ){
     return SQLITE_CORRUPT_BKPT;
@@ -5052,6 +5241,39 @@ int sqlite3PagerAcquire(
   if( pPager->errCode!=SQLITE_OK ){
     rc = pPager->errCode;
   }else{
+
+    if( bMmapOk && pagerUseWal(pPager) ){
+      rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
+      if( rc!=SQLITE_OK ) goto pager_acquire_err;
+    }
+
+    if( iFrame==0 && bMmapOk ){
+      void *pData = 0;
+
+      rc = sqlite3OsFetch(pPager->fd, 
+          (i64)(pgno-1) * pPager->pageSize, pPager->pageSize, &pData
+      );
+
+      if( rc==SQLITE_OK && pData ){
+        if( pPager->eState>PAGER_READER ){
+          (void)sqlite3PcacheFetch(pPager->pPCache, pgno, 0, &pPg);
+        }
+        if( pPg==0 ){
+          rc = pagerAcquireMapPage(pPager, pgno, pData, &pPg);
+        }else{
+          sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1)*pPager->pageSize, pData);
+        }
+        if( pPg ){
+          assert( rc==SQLITE_OK );
+          *ppPage = pPg;
+          return SQLITE_OK;
+        }
+      }
+      if( rc!=SQLITE_OK ){
+        goto pager_acquire_err;
+      }
+    }
+
     rc = sqlite3PcacheFetch(pPager->pPCache, pgno, 1, ppPage);
   }
 
@@ -5110,9 +5332,13 @@ int sqlite3PagerAcquire(
       memset(pPg->pData, 0, pPager->pageSize);
       IOTRACE(("ZERO %p %d\n", pPager, pgno));
     }else{
+      if( pagerUseWal(pPager) && bMmapOk==0 ){
+        rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
+        if( rc!=SQLITE_OK ) goto pager_acquire_err;
+      }
       assert( pPg->pPager==pPager );
       pPager->aStat[PAGER_STAT_MISS]++;
-      rc = readDbPage(pPg);
+      rc = readDbPage(pPg, iFrame);
       if( rc!=SQLITE_OK ){
         goto pager_acquire_err;
       }
@@ -5165,7 +5391,11 @@ DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){
 void sqlite3PagerUnref(DbPage *pPg){
   if( pPg ){
     Pager *pPager = pPg->pPager;
-    sqlite3PcacheRelease(pPg);
+    if( pPg->flags & PGHDR_MMAP ){
+      pagerReleaseMapPage(pPg);
+    }else{
+      sqlite3PcacheRelease(pPg);
+    }
     pagerUnlockIfUnused(pPager);
   }
 }
@@ -5500,6 +5730,7 @@ int sqlite3PagerWrite(DbPage *pDbPage){
   Pager *pPager = pPg->pPager;
   Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
 
+  assert( (pPg->flags & PGHDR_MMAP)==0 );
   assert( pPager->eState>=PAGER_WRITER_LOCKED );
   assert( pPager->eState!=PAGER_ERROR );
   assert( assert_pager_state(pPager) );
@@ -5699,6 +5930,11 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
           pPager->aStat[PAGER_STAT_WRITE]++;
         }
         if( rc==SQLITE_OK ){
+          /* Update the pager's copy of the change-counter. Otherwise, the
+          ** next time a read transaction is opened the cache will be
+          ** flushed (as the change-counter values will not match).  */
+          const void *pCopy = (const void *)&((const char *)zBuf)[24];
+          memcpy(&pPager->dbFileVers, pCopy, sizeof(pPager->dbFileVers));
           pPager->changeCountDone = 1;
         }
       }else{
@@ -5885,36 +6121,6 @@ int sqlite3PagerCommitPhaseOne(
   #endif
       if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
   
-      /* If this transaction has made the database smaller, then all pages
-      ** being discarded by the truncation must be written to the journal
-      ** file.
-      **
-      ** Before reading the pages with page numbers larger than the 
-      ** current value of Pager.dbSize, set dbSize back to the value
-      ** that it took at the start of the transaction. Otherwise, the
-      ** calls to sqlite3PagerGet() return zeroed pages instead of 
-      ** reading data from the database file.
-      */
-      if( pPager->dbSize<pPager->dbOrigSize 
-       && pPager->journalMode!=PAGER_JOURNALMODE_OFF
-      ){
-        Pgno i;                                   /* Iterator variable */
-        const Pgno iSkip = PAGER_MJ_PGNO(pPager); /* Pending lock page */
-        const Pgno dbSize = pPager->dbSize;       /* Database image size */ 
-        pPager->dbSize = pPager->dbOrigSize;
-        for( i=dbSize+1; i<=pPager->dbOrigSize; i++ ){
-          if( !sqlite3BitvecTest(pPager->pInJournal, i) && i!=iSkip ){
-            PgHdr *pPage;             /* Page to journal */
-            rc = sqlite3PagerGet(pPager, i, &pPage);
-            if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
-            rc = sqlite3PagerWrite(pPage);
-            sqlite3PagerUnref(pPage);
-            if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
-          }
-        }
-        pPager->dbSize = dbSize;
-      } 
-  
       /* Write the master journal name into the journal file. If a master 
       ** journal file name has already been written to the journal file, 
       ** or if zMaster is NULL (no master journal), then this call is a no-op.
@@ -5942,11 +6148,14 @@ int sqlite3PagerCommitPhaseOne(
         goto commit_phase_one_exit;
       }
       sqlite3PcacheCleanAll(pPager->pPCache);
-  
-      /* If the file on disk is not the same size as the database image,
-      ** then use pager_truncate to grow or shrink the file here.
-      */
-      if( pPager->dbSize!=pPager->dbFileSize ){
+
+      /* If the file on disk is smaller than the database image, use 
+      ** pager_truncate to grow the file here. This can happen if the database
+      ** image was extended as part of the current transaction and then the
+      ** last page in the db image moved to the free-list. In this case the
+      ** last page is never written out to disk, leaving the database file
+      ** undersized. Fix this now if it is the case.  */
+      if( pPager->dbSize>pPager->dbFileSize ){
         Pgno nNew = pPager->dbSize - (pPager->dbSize==PAGER_MJ_PGNO(pPager));
         assert( pPager->eState==PAGER_WRITER_DBMOD );
         rc = pager_truncate(pPager, nNew);
@@ -6019,7 +6228,7 @@ int sqlite3PagerCommitPhaseTwo(Pager *pPager){
   }
 
   PAGERTRACE(("COMMIT %d\n", PAGERID(pPager)));
-  rc = pager_end_transaction(pPager, pPager->setMaster);
+  rc = pager_end_transaction(pPager, pPager->setMaster, 1);
   return pager_error(pPager, rc);
 }
 
@@ -6064,11 +6273,11 @@ int sqlite3PagerRollback(Pager *pPager){
   if( pagerUseWal(pPager) ){
     int rc2;
     rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
-    rc2 = pager_end_transaction(pPager, pPager->setMaster);
+    rc2 = pager_end_transaction(pPager, pPager->setMaster, 0);
     if( rc==SQLITE_OK ) rc = rc2;
   }else if( !isOpen(pPager->jfd) || pPager->eState==PAGER_WRITER_LOCKED ){
     int eState = pPager->eState;
-    rc = pager_end_transaction(pPager, 0);
+    rc = pager_end_transaction(pPager, 0, 0);
     if( !MEMDB && eState>PAGER_WRITER_LOCKED ){
       /* This can happen using journal_mode=off. Move the pager to the error 
       ** state to indicate that the contents of the cache may not be trusted.
@@ -6083,7 +6292,7 @@ int sqlite3PagerRollback(Pager *pPager){
   }
 
   assert( pPager->eState==PAGER_READER || rc!=SQLITE_OK );
-  assert( rc==SQLITE_OK || rc==SQLITE_FULL
+  assert( rc==SQLITE_OK || rc==SQLITE_FULL || rc==SQLITE_CORRUPT
           || rc==SQLITE_NOMEM || (rc&0xFF)==SQLITE_IOERR );
 
   /* If an error occurs during a ROLLBACK, we can no longer trust the pager
@@ -6466,7 +6675,8 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
   */
   if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){
     needSyncPgno = pPg->pgno;
-    assert( pageInJournal(pPg) || pPg->pgno>pPager->dbOrigSize );
+    assert( pPager->journalMode==PAGER_JOURNALMODE_OFF ||
+            pageInJournal(pPg) || pPg->pgno>pPager->dbOrigSize );
     assert( pPg->flags&PGHDR_DIRTY );
   }
 
@@ -6816,11 +7026,12 @@ static int pagerOpenWal(Pager *pPager){
   ** (e.g. due to malloc() failure), return an error code.
   */
   if( rc==SQLITE_OK ){
-    rc = sqlite3WalOpen(pPager->pVfs, 
+    rc = sqlite3WalOpen(pPager->pVfs,
         pPager->fd, pPager->zWal, pPager->exclusiveMode,
         pPager->journalSizeLimit, &pPager->pWal
     );
   }
+  pagerFixMaplimit(pPager);
 
   return rc;
 }
@@ -6911,6 +7122,7 @@ int sqlite3PagerCloseWal(Pager *pPager){
       rc = sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags,
                            pPager->pageSize, (u8*)pPager->pTmpSpace);
       pPager->pWal = 0;
+      pagerFixMaplimit(pPager);
     }
   }
   return rc;
diff --git a/lib/libsqlite3/src/pager.h b/lib/libsqlite3/src/pager.h
index 90f8e6af787..6f659136e27 100644
--- a/lib/libsqlite3/src/pager.h
+++ b/lib/libsqlite3/src/pager.h
@@ -79,6 +79,12 @@ typedef struct PgHdr DbPage;
 #define PAGER_JOURNALMODE_WAL         5   /* Use write-ahead logging */
 
 /*
+** Flags that make up the mask passed to sqlite3PagerAcquire().
+*/
+#define PAGER_ACQUIRE_NOCONTENT     0x01  /* Do not load data from disk */
+#define PAGER_ACQUIRE_READONLY      0x02  /* Read-only page is acceptable */
+
+/*
 ** The remainder of this file contains the declarations of the functions
 ** that make up the Pager sub-system API. See source code comments for 
 ** a detailed description of each routine.
@@ -102,6 +108,7 @@ void sqlite3PagerSetBusyhandler(Pager*, int(*)(void *), void *);
 int sqlite3PagerSetPagesize(Pager*, u32*, int);
 int sqlite3PagerMaxPageCount(Pager*, int);
 void sqlite3PagerSetCachesize(Pager*, int);
+void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);
 void sqlite3PagerShrink(Pager*);
 void sqlite3PagerSetSafetyLevel(Pager*,int,int,int);
 int sqlite3PagerLockingMode(Pager *, int);
diff --git a/lib/libsqlite3/src/pcache.h b/lib/libsqlite3/src/pcache.h
index b9135fd8593..f4d4ad71c10 100644
--- a/lib/libsqlite3/src/pcache.h
+++ b/lib/libsqlite3/src/pcache.h
@@ -53,6 +53,8 @@ struct PgHdr {
 #define PGHDR_REUSE_UNLIKELY    0x010  /* A hint that reuse is unlikely */
 #define PGHDR_DONT_WRITE        0x020  /* Do not write content to disk */
 
+#define PGHDR_MMAP              0x040  /* This is an mmap page object */
+
 /* Initialize and shutdown the page cache subsystem */
 int sqlite3PcacheInitialize(void);
 void sqlite3PcacheShutdown(void);
diff --git a/lib/libsqlite3/src/pragma.c b/lib/libsqlite3/src/pragma.c
index d3061b234f9..3056a7d8e2b 100644
--- a/lib/libsqlite3/src/pragma.c
+++ b/lib/libsqlite3/src/pragma.c
@@ -184,6 +184,9 @@ static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
     { "sql_trace",                SQLITE_SqlTrace      },
     { "vdbe_listing",             SQLITE_VdbeListing   },
     { "vdbe_trace",               SQLITE_VdbeTrace     },
+    { "vdbe_addoptrace",          SQLITE_VdbeAddopTrace},
+    { "vdbe_debug",    SQLITE_SqlTrace | SQLITE_VdbeListing
+                               | SQLITE_VdbeTrace      },
 #endif
 #ifndef SQLITE_OMIT_CHECK
     { "ignore_check_constraints", SQLITE_IgnoreChecks  },
@@ -316,7 +319,7 @@ void sqlite3Pragma(
   int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
   sqlite3 *db = pParse->db;    /* The database connection */
   Db *pDb;                     /* The specific database being pragmaed */
-  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);  /* Prepared statement */
+  Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */
 
   if( v==0 ) return;
   sqlite3VdbeRunOnlyOnce(v);
@@ -399,11 +402,12 @@ void sqlite3Pragma(
     static const VdbeOpList getCacheSize[] = {
       { OP_Transaction, 0, 0,        0},                         /* 0 */
       { OP_ReadCookie,  0, 1,        BTREE_DEFAULT_CACHE_SIZE},  /* 1 */
-      { OP_IfPos,       1, 7,        0},
+      { OP_IfPos,       1, 8,        0},
       { OP_Integer,     0, 2,        0},
       { OP_Subtract,    1, 2,        1},
-      { OP_IfPos,       1, 7,        0},
+      { OP_IfPos,       1, 8,        0},
       { OP_Integer,     0, 1,        0},                         /* 6 */
+      { OP_Noop,        0, 0,        0},
       { OP_ResultRow,   1, 1,        0},
     };
     int addr;
@@ -742,6 +746,43 @@ void sqlite3Pragma(
   }else
 
   /*
+  **  PRAGMA [database.]mmap_size(N)
+  **
+  ** Used to set mapping size limit. The mapping size limit is
+  ** used to limit the aggregate size of all memory mapped regions of the
+  ** database file. If this parameter is set to zero, then memory mapping
+  ** is not used at all.  If N is negative, then the default memory map
+  ** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.
+  ** The parameter N is measured in bytes.
+  **
+  ** This value is advisory.  The underlying VFS is free to memory map
+  ** as little or as much as it wants.  Except, if N is set to 0 then the
+  ** upper layers will never invoke the xFetch interfaces to the VFS.
+  */
+  if( sqlite3StrICmp(zLeft,"mmap_size")==0 ){
+    sqlite3_int64 sz;
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    if( zRight ){
+      int ii;
+      sqlite3Atoi64(zRight, &sz, 1000, SQLITE_UTF8);
+      if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;
+      if( pId2->n==0 ) db->szMmap = sz;
+      for(ii=db->nDb-1; ii>=0; ii--){
+        if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
+          sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);
+        }
+      }
+    }
+    sz = -1;
+    if( sqlite3_file_control(db,zDb,SQLITE_FCNTL_MMAP_SIZE,&sz)==SQLITE_OK ){
+#if SQLITE_MAX_MMAP_SIZE==0
+      sz = 0;
+#endif
+      returnSingleInt(pParse, "mmap_size", sz);
+    }
+  }else
+
+  /*
   **   PRAGMA temp_store
   **   PRAGMA temp_store = "default"|"memory"|"file"
   **
@@ -948,11 +989,14 @@ void sqlite3Pragma(
     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
     pTab = sqlite3FindTable(db, zRight, zDb);
     if( pTab ){
-      int i;
+      int i, k;
       int nHidden = 0;
       Column *pCol;
+      Index *pPk;
+      for(pPk=pTab->pIndex; pPk && pPk->autoIndex!=2; pPk=pPk->pNext){}
       sqlite3VdbeSetNumCols(v, 6);
       pParse->nMem = 6;
+      sqlite3CodeVerifySchema(pParse, iDb);
       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", SQLITE_STATIC);
       sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
       sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", SQLITE_STATIC);
@@ -975,8 +1019,14 @@ void sqlite3Pragma(
         }else{
           sqlite3VdbeAddOp2(v, OP_Null, 0, 5);
         }
-        sqlite3VdbeAddOp2(v, OP_Integer,
-                            (pCol->colFlags&COLFLAG_PRIMKEY)!=0, 6);
+        if( (pCol->colFlags & COLFLAG_PRIMKEY)==0 ){
+          k = 0;
+        }else if( pPk==0 ){
+          k = 1;
+        }else{
+          for(k=1; ALWAYS(k<=pTab->nCol) && pPk->aiColumn[k-1]!=i; k++){}
+        }
+        sqlite3VdbeAddOp2(v, OP_Integer, k, 6);
         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
       }
     }
@@ -992,6 +1042,7 @@ void sqlite3Pragma(
       pTab = pIdx->pTable;
       sqlite3VdbeSetNumCols(v, 3);
       pParse->nMem = 3;
+      sqlite3CodeVerifySchema(pParse, iDb);
       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", SQLITE_STATIC);
       sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", SQLITE_STATIC);
       sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", SQLITE_STATIC);
@@ -1018,6 +1069,7 @@ void sqlite3Pragma(
         int i = 0; 
         sqlite3VdbeSetNumCols(v, 3);
         pParse->nMem = 3;
+        sqlite3CodeVerifySchema(pParse, iDb);
         sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
         sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
         sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
@@ -1081,6 +1133,7 @@ void sqlite3Pragma(
         int i = 0; 
         sqlite3VdbeSetNumCols(v, 8);
         pParse->nMem = 8;
+        sqlite3CodeVerifySchema(pParse, iDb);
         sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", SQLITE_STATIC);
         sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", SQLITE_STATIC);
         sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", SQLITE_STATIC);
@@ -1114,6 +1167,122 @@ void sqlite3Pragma(
   }else
 #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
 
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+#ifndef SQLITE_OMIT_TRIGGER
+  if( sqlite3StrICmp(zLeft, "foreign_key_check")==0 ){
+    FKey *pFK;             /* A foreign key constraint */
+    Table *pTab;           /* Child table contain "REFERENCES" keyword */
+    Table *pParent;        /* Parent table that child points to */
+    Index *pIdx;           /* Index in the parent table */
+    int i;                 /* Loop counter:  Foreign key number for pTab */
+    int j;                 /* Loop counter:  Field of the foreign key */
+    HashElem *k;           /* Loop counter:  Next table in schema */
+    int x;                 /* result variable */
+    int regResult;         /* 3 registers to hold a result row */
+    int regKey;            /* Register to hold key for checking the FK */
+    int regRow;            /* Registers to hold a row from pTab */
+    int addrTop;           /* Top of a loop checking foreign keys */
+    int addrOk;            /* Jump here if the key is OK */
+    int *aiCols;           /* child to parent column mapping */
+
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    regResult = pParse->nMem+1;
+    pParse->nMem += 4;
+    regKey = ++pParse->nMem;
+    regRow = ++pParse->nMem;
+    v = sqlite3GetVdbe(pParse);
+    sqlite3VdbeSetNumCols(v, 4);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "table", SQLITE_STATIC);
+    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "rowid", SQLITE_STATIC);
+    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "parent", SQLITE_STATIC);
+    sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "fkid", SQLITE_STATIC);
+    sqlite3CodeVerifySchema(pParse, iDb);
+    k = sqliteHashFirst(&db->aDb[iDb].pSchema->tblHash);
+    while( k ){
+      if( zRight ){
+        pTab = sqlite3LocateTable(pParse, 0, zRight, zDb);
+        k = 0;
+      }else{
+        pTab = (Table*)sqliteHashData(k);
+        k = sqliteHashNext(k);
+      }
+      if( pTab==0 || pTab->pFKey==0 ) continue;
+      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+      if( pTab->nCol+regRow>pParse->nMem ) pParse->nMem = pTab->nCol + regRow;
+      sqlite3OpenTable(pParse, 0, iDb, pTab, OP_OpenRead);
+      sqlite3VdbeAddOp4(v, OP_String8, 0, regResult, 0, pTab->zName,
+                        P4_TRANSIENT);
+      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
+        pParent = sqlite3LocateTable(pParse, 0, pFK->zTo, zDb);
+        if( pParent==0 ) break;
+        pIdx = 0;
+        sqlite3TableLock(pParse, iDb, pParent->tnum, 0, pParent->zName);
+        x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, 0);
+        if( x==0 ){
+          if( pIdx==0 ){
+            sqlite3OpenTable(pParse, i, iDb, pParent, OP_OpenRead);
+          }else{
+            KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
+            sqlite3VdbeAddOp3(v, OP_OpenRead, i, pIdx->tnum, iDb);
+            sqlite3VdbeChangeP4(v, -1, (char*)pKey, P4_KEYINFO_HANDOFF);
+          }
+        }else{
+          k = 0;
+          break;
+        }
+      }
+      if( pFK ) break;
+      if( pParse->nTab<i ) pParse->nTab = i;
+      addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, 0);
+      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
+        pParent = sqlite3LocateTable(pParse, 0, pFK->zTo, zDb);
+        assert( pParent!=0 );
+        pIdx = 0;
+        aiCols = 0;
+        x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);
+        assert( x==0 );
+        addrOk = sqlite3VdbeMakeLabel(v);
+        if( pIdx==0 ){
+          int iKey = pFK->aCol[0].iFrom;
+          assert( iKey>=0 && iKey<pTab->nCol );
+          if( iKey!=pTab->iPKey ){
+            sqlite3VdbeAddOp3(v, OP_Column, 0, iKey, regRow);
+            sqlite3ColumnDefault(v, pTab, iKey, regRow);
+            sqlite3VdbeAddOp2(v, OP_IsNull, regRow, addrOk);
+            sqlite3VdbeAddOp2(v, OP_MustBeInt, regRow,
+               sqlite3VdbeCurrentAddr(v)+3);
+          }else{
+            sqlite3VdbeAddOp2(v, OP_Rowid, 0, regRow);
+          }
+          sqlite3VdbeAddOp3(v, OP_NotExists, i, 0, regRow);
+          sqlite3VdbeAddOp2(v, OP_Goto, 0, addrOk);
+          sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
+        }else{
+          for(j=0; j<pFK->nCol; j++){
+            sqlite3ExprCodeGetColumnOfTable(v, pTab, 0,
+                            aiCols ? aiCols[j] : pFK->aCol[0].iFrom, regRow+j);
+            sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk);
+          }
+          sqlite3VdbeAddOp3(v, OP_MakeRecord, regRow, pFK->nCol, regKey);
+          sqlite3VdbeChangeP4(v, -1,
+                   sqlite3IndexAffinityStr(v,pIdx), P4_TRANSIENT);
+          sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
+        }
+        sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
+        sqlite3VdbeAddOp4(v, OP_String8, 0, regResult+2, 0, 
+                          pFK->zTo, P4_TRANSIENT);
+        sqlite3VdbeAddOp2(v, OP_Integer, i-1, regResult+3);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
+        sqlite3VdbeResolveLabel(v, addrOk);
+        sqlite3DbFree(db, aiCols);
+      }
+      sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1);
+      sqlite3VdbeJumpHere(v, addrTop);
+    }
+  }else
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
+#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
+
 #ifndef NDEBUG
   if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){
     if( zRight ){
@@ -1398,6 +1567,11 @@ void sqlite3Pragma(
   **   PRAGMA [database.]user_version
   **   PRAGMA [database.]user_version = <integer>
   **
+  **   PRAGMA [database.]freelist_count = <integer>
+  **
+  **   PRAGMA [database.]application_id
+  **   PRAGMA [database.]application_id = <integer>
+  **
   ** The pragma's schema_version and user_version are used to set or get
   ** the value of the schema-version and user-version, respectively. Both
   ** the schema-version and the user-version are 32-bit signed integers
@@ -1419,10 +1593,14 @@ void sqlite3Pragma(
   if( sqlite3StrICmp(zLeft, "schema_version")==0 
    || sqlite3StrICmp(zLeft, "user_version")==0 
    || sqlite3StrICmp(zLeft, "freelist_count")==0 
+   || sqlite3StrICmp(zLeft, "application_id")==0 
   ){
     int iCookie;   /* Cookie index. 1 for schema-cookie, 6 for user-cookie. */
     sqlite3VdbeUsesBtree(v, iDb);
     switch( zLeft[0] ){
+      case 'a': case 'A':
+        iCookie = BTREE_APPLICATION_ID;
+        break;
       case 'f': case 'F':
         iCookie = BTREE_FREE_PAGE_COUNT;
         break;
@@ -1611,7 +1789,7 @@ void sqlite3Pragma(
   }else
 #endif
 #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
-  if( sqlite3StrICmp(zLeft, "activate_extensions")==0 ){
+  if( sqlite3StrICmp(zLeft, "activate_extensions")==0 && zRight ){
 #ifdef SQLITE_HAS_CODEC
     if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
       sqlite3_activate_see(&zRight[4]);
diff --git a/lib/libsqlite3/src/prepare.c b/lib/libsqlite3/src/prepare.c
index 5ac8de7296f..d78d83cbd87 100644
--- a/lib/libsqlite3/src/prepare.c
+++ b/lib/libsqlite3/src/prepare.c
@@ -179,7 +179,7 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
 
   /* zMasterSchema and zInitScript are set to point at the master schema
   ** and initialisation script appropriate for the database being
-  ** initialised. zMasterName is the name of the master table.
+  ** initialized. zMasterName is the name of the master table.
   */
   if( !OMIT_TEMPDB && iDb==1 ){
     zMasterSchema = temp_master_schema;
@@ -259,11 +259,15 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   */
   if( meta[BTREE_TEXT_ENCODING-1] ){  /* text encoding */
     if( iDb==0 ){
+#ifndef SQLITE_OMIT_UTF16
       u8 encoding;
       /* If opening the main database, set ENC(db). */
       encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
       if( encoding==0 ) encoding = SQLITE_UTF8;
       ENC(db) = encoding;
+#else
+      ENC(db) = SQLITE_UTF8;
+#endif
     }else{
       /* If opening an attached database, the encoding much match ENC(db) */
       if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){
@@ -400,7 +404,7 @@ int sqlite3Init(sqlite3 *db, char **pzErrMsg){
     }
   }
 
-  /* Once all the other databases have been initialised, load the schema
+  /* Once all the other databases have been initialized, load the schema
   ** for the TEMP database. This is loaded last, as the TEMP database
   ** schema may contain references to objects in other databases.
   */
@@ -423,7 +427,7 @@ int sqlite3Init(sqlite3 *db, char **pzErrMsg){
 }
 
 /*
-** This routine is a no-op if the database schema is already initialised.
+** This routine is a no-op if the database schema is already initialized.
 ** Otherwise, the schema is loaded. An error code is returned.
 */
 int sqlite3ReadSchema(Parse *pParse){
@@ -650,7 +654,6 @@ static int sqlite3Prepare(
   }
 #endif
 
-  assert( db->init.busy==0 || saveSqlFlag==0 );
   if( db->init.busy==0 ){
     Vdbe *pVdbe = pParse->pVdbe;
     sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag);
diff --git a/lib/libsqlite3/src/resolve.c b/lib/libsqlite3/src/resolve.c
index 51aab7792b8..91efcaa1a16 100644
--- a/lib/libsqlite3/src/resolve.c
+++ b/lib/libsqlite3/src/resolve.c
@@ -150,6 +150,35 @@ static int nameInUsingClause(IdList *pUsing, const char *zCol){
   return 0;
 }
 
+/*
+** Subqueries stores the original database, table and column names for their
+** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN".
+** Check to see if the zSpan given to this routine matches the zDb, zTab,
+** and zCol.  If any of zDb, zTab, and zCol are NULL then those fields will
+** match anything.
+*/
+int sqlite3MatchSpanName(
+  const char *zSpan,
+  const char *zCol,
+  const char *zTab,
+  const char *zDb
+){
+  int n;
+  for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
+  if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){
+    return 0;
+  }
+  zSpan += n+1;
+  for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
+  if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){
+    return 0;
+  }
+  zSpan += n+1;
+  if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){
+    return 0;
+  }
+  return 1;
+}
 
 /*
 ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
@@ -206,6 +235,20 @@ static int lookupName(
   pExpr->pTab = 0;
   ExprSetIrreducible(pExpr);
 
+  /* Translate the schema name in zDb into a pointer to the corresponding
+  ** schema.  If not found, pSchema will remain NULL and nothing will match
+  ** resulting in an appropriate error message toward the end of this routine
+  */
+  if( zDb ){
+    for(i=0; i<db->nDb; i++){
+      assert( db->aDb[i].zName );
+      if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
+        pSchema = db->aDb[i].pSchema;
+        break;
+      }
+    }
+  }
+
   /* Start at the inner-most context and move outward until a match is found */
   while( pNC && cnt==0 ){
     ExprList *pEList;
@@ -214,31 +257,36 @@ static int lookupName(
     if( pSrcList ){
       for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
         Table *pTab;
-        int iDb;
         Column *pCol;
   
         pTab = pItem->pTab;
         assert( pTab!=0 && pTab->zName!=0 );
-        iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
         assert( pTab->nCol>0 );
-        if( zTab ){
-          if( pItem->zAlias ){
-            char *zTabName = pItem->zAlias;
-            if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
-          }else{
-            char *zTabName = pTab->zName;
-            if( NEVER(zTabName==0) || sqlite3StrICmp(zTabName, zTab)!=0 ){
-              continue;
-            }
-            if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
-              continue;
+        if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){
+          int hit = 0;
+          pEList = pItem->pSelect->pEList;
+          for(j=0; j<pEList->nExpr; j++){
+            if( sqlite3MatchSpanName(pEList->a[j].zSpan, zCol, zTab, zDb) ){
+              cnt++;
+              cntTab = 2;
+              pMatch = pItem;
+              pExpr->iColumn = j;
+              hit = 1;
             }
           }
+          if( hit || zTab==0 ) continue;
+        }
+        if( zDb && pTab->pSchema!=pSchema ){
+          continue;
+        }
+        if( zTab ){
+          const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName;
+          assert( zTabName!=0 );
+          if( sqlite3StrICmp(zTabName, zTab)!=0 ){
+            continue;
+          }
         }
         if( 0==(cntTab++) ){
-          pExpr->iTable = pItem->iCursor;
-          pExpr->pTab = pTab;
-          pSchema = pTab->pSchema;
           pMatch = pItem;
         }
         for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
@@ -252,17 +300,19 @@ static int lookupName(
               if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
             }
             cnt++;
-            pExpr->iTable = pItem->iCursor;
-            pExpr->pTab = pTab;
             pMatch = pItem;
-            pSchema = pTab->pSchema;
             /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
             pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
             break;
           }
         }
       }
-    }
+      if( pMatch ){
+        pExpr->iTable = pMatch->iCursor;
+        pExpr->pTab = pMatch->pTab;
+        pSchema = pExpr->pTab->pSchema;
+      }
+    } /* if( pSrcList ) */
 
 #ifndef SQLITE_OMIT_TRIGGER
     /* If we have not already resolved the name, then maybe 
@@ -338,7 +388,10 @@ static int lookupName(
     ** Note that the expression in the result set should have already been
     ** resolved by the time the WHERE clause is resolved.
     */
-    if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
+    if( (pEList = pNC->pEList)!=0
+     && zTab==0
+     && ((pNC->ncFlags & NC_AsMaybe)==0 || cnt==0)
+    ){
       for(j=0; j<pEList->nExpr; j++){
         char *zAs = pEList->a[j].zName;
         if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
@@ -429,7 +482,9 @@ static int lookupName(
 lookupname_end:
   if( cnt==1 ){
     assert( pNC!=0 );
-    sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+    if( pExpr->op!=TK_AS ){
+      sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+    }
     /* Increment the nRef value on all name contexts from TopNC up to
     ** the point where the name matched. */
     for(;;){
@@ -597,7 +652,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
         sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
         pNC->nErr++;
         is_agg = 0;
-      }else if( no_such_func ){
+      }else if( no_such_func && pParse->db->init.busy==0 ){
         sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
         pNC->nErr++;
       }else if( wrong_num_args ){
@@ -1033,23 +1088,6 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
       return WRC_Abort;
     }
   
-    /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
-    ** resolve the result-set expression list.
-    */
-    sNC.ncFlags = NC_AllowAgg;
-    sNC.pSrcList = p->pSrc;
-    sNC.pNext = pOuterNC;
-  
-    /* Resolve names in the result set. */
-    pEList = p->pEList;
-    assert( pEList!=0 );
-    for(i=0; i<pEList->nExpr; i++){
-      Expr *pX = pEList->a[i].pExpr;
-      if( sqlite3ResolveExprNames(&sNC, pX) ){
-        return WRC_Abort;
-      }
-    }
-  
     /* Recursively resolve names in all subqueries
     */
     for(i=0; i<p->pSrc->nSrc; i++){
@@ -1077,6 +1115,23 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
       }
     }
   
+    /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
+    ** resolve the result-set expression list.
+    */
+    sNC.ncFlags = NC_AllowAgg;
+    sNC.pSrcList = p->pSrc;
+    sNC.pNext = pOuterNC;
+  
+    /* Resolve names in the result set. */
+    pEList = p->pEList;
+    assert( pEList!=0 );
+    for(i=0; i<pEList->nExpr; i++){
+      Expr *pX = pEList->a[i].pExpr;
+      if( sqlite3ResolveExprNames(&sNC, pX) ){
+        return WRC_Abort;
+      }
+    }
+  
     /* If there are no aggregate functions in the result-set, and no GROUP BY 
     ** expression, do not allow aggregates in any of the other expressions.
     */
@@ -1104,11 +1159,10 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     ** re-evaluated for each reference to it.
     */
     sNC.pEList = p->pEList;
-    if( sqlite3ResolveExprNames(&sNC, p->pWhere) ||
-       sqlite3ResolveExprNames(&sNC, p->pHaving)
-    ){
-      return WRC_Abort;
-    }
+    sNC.ncFlags |= NC_AsMaybe;
+    if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
+    if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;
+    sNC.ncFlags &= ~NC_AsMaybe;
 
     /* The ORDER BY and GROUP BY clauses may not refer to terms in
     ** outer queries 
@@ -1229,6 +1283,7 @@ int sqlite3ResolveExprNames(
 #endif
   savedHasAgg = pNC->ncFlags & NC_HasAgg;
   pNC->ncFlags &= ~NC_HasAgg;
+  memset(&w, 0, sizeof(w));
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
   w.pParse = pNC->pParse;
@@ -1269,6 +1324,7 @@ void sqlite3ResolveSelectNames(
   Walker w;
 
   assert( p!=0 );
+  memset(&w, 0, sizeof(w));
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
   w.pParse = pParse;
diff --git a/lib/libsqlite3/src/select.c b/lib/libsqlite3/src/select.c
index a90877dc612..f3f14909639 100644
--- a/lib/libsqlite3/src/select.c
+++ b/lib/libsqlite3/src/select.c
@@ -55,7 +55,7 @@ Select *sqlite3SelectNew(
   ExprList *pGroupBy,   /* the GROUP BY clause */
   Expr *pHaving,        /* the HAVING clause */
   ExprList *pOrderBy,   /* the ORDER BY clause */
-  int isDistinct,       /* true if the DISTINCT keyword is present */
+  u16 selFlags,         /* Flag parameters, such as SF_Distinct */
   Expr *pLimit,         /* LIMIT value.  NULL means not used */
   Expr *pOffset         /* OFFSET value.  NULL means no offset */
 ){
@@ -79,7 +79,7 @@ Select *sqlite3SelectNew(
   pNew->pGroupBy = pGroupBy;
   pNew->pHaving = pHaving;
   pNew->pOrderBy = pOrderBy;
-  pNew->selFlags = isDistinct ? SF_Distinct : 0;
+  pNew->selFlags = selFlags;
   pNew->op = TK_SELECT;
   pNew->pLimit = pLimit;
   pNew->pOffset = pOffset;
@@ -1336,8 +1336,6 @@ static int selectColumnsFromExprList(
     /* Get an appropriate name for the column
     */
     p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
-    assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue)
-               || p->pRight->u.zToken==0 || p->pRight->u.zToken[0]!=0 );
     if( (zName = pEList->a[i].zName)!=0 ){
       /* If the column contains an "AS <name>" phrase, use <name> as the name */
       zName = sqlite3DbStrDup(db, zName);
@@ -1375,6 +1373,9 @@ static int selectColumnsFromExprList(
     for(j=cnt=0; j<i; j++){
       if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
         char *zNewName;
+        int k;
+        for(k=nName-1; k>1 && sqlite3Isdigit(zName[k]); k--){}
+        if( zName[k]==':' ) nName = k;
         zName[nName] = 0;
         zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt);
         sqlite3DbFree(db, zName);
@@ -1706,6 +1707,8 @@ static int multiSelect(
       int addr = 0;
       int nLimit;
       assert( !pPrior->pLimit );
+      pPrior->iLimit = p->iLimit;
+      pPrior->iOffset = p->iOffset;
       pPrior->pLimit = p->pLimit;
       pPrior->pOffset = p->pOffset;
       explainSetInteger(iSub1, pParse->iNextSelectId);
@@ -2363,7 +2366,8 @@ static int multiSelectOrderBy(
   }else{
     int nExpr = p->pEList->nExpr;
     assert( nOrderBy>=nExpr || db->mallocFailed );
-    regPrev = sqlite3GetTempRange(pParse, nExpr+1);
+    regPrev = pParse->nMem+1;
+    pParse->nMem += nExpr+1;
     sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
     pKeyDup = sqlite3DbMallocZero(db,
                   sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) );
@@ -2545,12 +2549,6 @@ static int multiSelectOrderBy(
   sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
   sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);
 
-  /* Release temporary registers
-  */
-  if( regPrev ){
-    sqlite3ReleaseTempRange(pParse, regPrev, nOrderBy+1);
-  }
-
   /* Jump to the this point in order to terminate the query.
   */
   sqlite3VdbeResolveLabel(v, labelEnd);
@@ -2962,12 +2960,15 @@ static int flattenSubquery(
     Select *pNew;
     ExprList *pOrderBy = p->pOrderBy;
     Expr *pLimit = p->pLimit;
+    Expr *pOffset = p->pOffset;
     Select *pPrior = p->pPrior;
     p->pOrderBy = 0;
     p->pSrc = 0;
     p->pPrior = 0;
     p->pLimit = 0;
+    p->pOffset = 0;
     pNew = sqlite3SelectDup(db, p, 0);
+    p->pOffset = pOffset;
     p->pLimit = pLimit;
     p->pOrderBy = pOrderBy;
     p->pSrc = pSrc;
@@ -3160,34 +3161,43 @@ static int flattenSubquery(
 #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
 
 /*
-** Analyze the SELECT statement passed as an argument to see if it
-** is a min() or max() query. Return WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX if 
-** it is, or 0 otherwise. At present, a query is considered to be
-** a min()/max() query if:
+** Based on the contents of the AggInfo structure indicated by the first
+** argument, this function checks if the following are true:
 **
-**   1. There is a single object in the FROM clause.
+**    * the query contains just a single aggregate function,
+**    * the aggregate function is either min() or max(), and
+**    * the argument to the aggregate function is a column value.
 **
-**   2. There is a single expression in the result set, and it is
-**      either min(x) or max(x), where x is a column reference.
+** If all of the above are true, then WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX
+** is returned as appropriate. Also, *ppMinMax is set to point to the 
+** list of arguments passed to the aggregate before returning.
+**
+** Or, if the conditions above are not met, *ppMinMax is set to 0 and
+** WHERE_ORDERBY_NORMAL is returned.
 */
-static u8 minMaxQuery(Select *p){
-  Expr *pExpr;
-  ExprList *pEList = p->pEList;
-
-  if( pEList->nExpr!=1 ) return WHERE_ORDERBY_NORMAL;
-  pExpr = pEList->a[0].pExpr;
-  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
-  if( NEVER(ExprHasProperty(pExpr, EP_xIsSelect)) ) return 0;
-  pEList = pExpr->x.pList;
-  if( pEList==0 || pEList->nExpr!=1 ) return 0;
-  if( pEList->a[0].pExpr->op!=TK_AGG_COLUMN ) return WHERE_ORDERBY_NORMAL;
-  assert( !ExprHasProperty(pExpr, EP_IntValue) );
-  if( sqlite3StrICmp(pExpr->u.zToken,"min")==0 ){
-    return WHERE_ORDERBY_MIN;
-  }else if( sqlite3StrICmp(pExpr->u.zToken,"max")==0 ){
-    return WHERE_ORDERBY_MAX;
+static u8 minMaxQuery(AggInfo *pAggInfo, ExprList **ppMinMax){
+  int eRet = WHERE_ORDERBY_NORMAL;          /* Return value */
+
+  *ppMinMax = 0;
+  if( pAggInfo->nFunc==1 ){
+    Expr *pExpr = pAggInfo->aFunc[0].pExpr; /* Aggregate function */
+    ExprList *pEList = pExpr->x.pList;      /* Arguments to agg function */
+
+    assert( pExpr->op==TK_AGG_FUNCTION );
+    if( pEList && pEList->nExpr==1 && pEList->a[0].pExpr->op==TK_AGG_COLUMN ){
+      const char *zFunc = pExpr->u.zToken;
+      if( sqlite3StrICmp(zFunc, "min")==0 ){
+        eRet = WHERE_ORDERBY_MIN;
+        *ppMinMax = pEList;
+      }else if( sqlite3StrICmp(zFunc, "max")==0 ){
+        eRet = WHERE_ORDERBY_MAX;
+        *ppMinMax = pEList;
+      }
+    }
   }
-  return WHERE_ORDERBY_NORMAL;
+
+  assert( *ppMinMax==0 || (*ppMinMax)->nExpr==1 );
+  return eRet;
 }
 
 /*
@@ -3250,6 +3260,69 @@ int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
   }
   return SQLITE_OK;
 }
+/*
+** Detect compound SELECT statements that use an ORDER BY clause with 
+** an alternative collating sequence.
+**
+**    SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ...
+**
+** These are rewritten as a subquery:
+**
+**    SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2)
+**     ORDER BY ... COLLATE ...
+**
+** This transformation is necessary because the multiSelectOrderBy() routine
+** above that generates the code for a compound SELECT with an ORDER BY clause
+** uses a merge algorithm that requires the same collating sequence on the
+** result columns as on the ORDER BY clause.  See ticket
+** http://www.sqlite.org/src/info/6709574d2a
+**
+** This transformation is only needed for EXCEPT, INTERSECT, and UNION.
+** The UNION ALL operator works fine with multiSelectOrderBy() even when
+** there are COLLATE terms in the ORDER BY.
+*/
+static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
+  int i;
+  Select *pNew;
+  Select *pX;
+  sqlite3 *db;
+  struct ExprList_item *a;
+  SrcList *pNewSrc;
+  Parse *pParse;
+  Token dummy;
+
+  if( p->pPrior==0 ) return WRC_Continue;
+  if( p->pOrderBy==0 ) return WRC_Continue;
+  for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}
+  if( pX==0 ) return WRC_Continue;
+  a = p->pOrderBy->a;
+  for(i=p->pOrderBy->nExpr-1; i>=0; i--){
+    if( a[i].pExpr->flags & EP_Collate ) break;
+  }
+  if( i<0 ) return WRC_Continue;
+
+  /* If we reach this point, that means the transformation is required. */
+
+  pParse = pWalker->pParse;
+  db = pParse->db;
+  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
+  if( pNew==0 ) return WRC_Abort;
+  memset(&dummy, 0, sizeof(dummy));
+  pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0);
+  if( pNewSrc==0 ) return WRC_Abort;
+  *pNew = *p;
+  p->pSrc = pNewSrc;
+  p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ALL, 0));
+  p->op = TK_SELECT;
+  p->pWhere = 0;
+  pNew->pGroupBy = 0;
+  pNew->pHaving = 0;
+  pNew->pOrderBy = 0;
+  p->pPrior = 0;
+  pNew->pLimit = 0;
+  pNew->pOffset = 0;
+  return WRC_Continue;
+}
 
 /*
 ** This routine is a Walker callback for "expanding" a SELECT statement.
@@ -3282,14 +3355,16 @@ static int selectExpander(Walker *pWalker, Select *p){
   ExprList *pEList;
   struct SrcList_item *pFrom;
   sqlite3 *db = pParse->db;
+  Expr *pE, *pRight, *pExpr;
+  u16 selFlags = p->selFlags;
 
+  p->selFlags |= SF_Expanded;
   if( db->mallocFailed  ){
     return WRC_Abort;
   }
-  if( NEVER(p->pSrc==0) || (p->selFlags & SF_Expanded)!=0 ){
+  if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
     return WRC_Prune;
   }
-  p->selFlags |= SF_Expanded;
   pTabList = p->pSrc;
   pEList = p->pEList;
 
@@ -3332,6 +3407,12 @@ static int selectExpander(Walker *pWalker, Select *p){
       assert( pFrom->pTab==0 );
       pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
       if( pTab==0 ) return WRC_Abort;
+      if( pTab->nRef==0xffff ){
+        sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
+           pTab->zName);
+        pFrom->pTab = 0;
+        return WRC_Abort;
+      }
       pTab->nRef++;
 #if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
       if( pTab->pSelect || IsVirtual(pTab) ){
@@ -3367,7 +3448,7 @@ static int selectExpander(Walker *pWalker, Select *p){
   ** that need expanding.
   */
   for(k=0; k<pEList->nExpr; k++){
-    Expr *pE = pEList->a[k].pExpr;
+    pE = pEList->a[k].pExpr;
     if( pE->op==TK_ALL ) break;
     assert( pE->op!=TK_DOT || pE->pRight!=0 );
     assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
@@ -3385,10 +3466,18 @@ static int selectExpander(Walker *pWalker, Select *p){
     int longNames = (flags & SQLITE_FullColNames)!=0
                       && (flags & SQLITE_ShortColNames)==0;
 
+    /* When processing FROM-clause subqueries, it is always the case
+    ** that full_column_names=OFF and short_column_names=ON.  The
+    ** sqlite3ResultSetOfSelect() routine makes it so. */
+    assert( (p->selFlags & SF_NestedFrom)==0
+          || ((flags & SQLITE_FullColNames)==0 &&
+              (flags & SQLITE_ShortColNames)!=0) );
+
     for(k=0; k<pEList->nExpr; k++){
-      Expr *pE = a[k].pExpr;
-      assert( pE->op!=TK_DOT || pE->pRight!=0 );
-      if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pE->pRight->op!=TK_ALL) ){
+      pE = a[k].pExpr;
+      pRight = pE->pRight;
+      assert( pE->op!=TK_DOT || pRight!=0 );
+      if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pRight->op!=TK_ALL) ){
         /* This particular expression does not need to be expanded.
         */
         pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
@@ -3403,32 +3492,43 @@ static int selectExpander(Walker *pWalker, Select *p){
         /* This expression is a "*" or a "TABLE.*" and needs to be
         ** expanded. */
         int tableSeen = 0;      /* Set to 1 when TABLE matches */
-        char *zTName;            /* text of name of TABLE */
+        char *zTName = 0;       /* text of name of TABLE */
         if( pE->op==TK_DOT ){
           assert( pE->pLeft!=0 );
           assert( !ExprHasProperty(pE->pLeft, EP_IntValue) );
           zTName = pE->pLeft->u.zToken;
-        }else{
-          zTName = 0;
         }
         for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
           Table *pTab = pFrom->pTab;
+          Select *pSub = pFrom->pSelect;
           char *zTabName = pFrom->zAlias;
+          const char *zSchemaName = 0;
+          int iDb;
           if( zTabName==0 ){
             zTabName = pTab->zName;
           }
           if( db->mallocFailed ) break;
-          if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
-            continue;
+          if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){
+            pSub = 0;
+            if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
+              continue;
+            }
+            iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+            zSchemaName = iDb>=0 ? db->aDb[iDb].zName : "*";
           }
-          tableSeen = 1;
           for(j=0; j<pTab->nCol; j++){
-            Expr *pExpr, *pRight;
             char *zName = pTab->aCol[j].zName;
             char *zColname;  /* The computed column name */
             char *zToFree;   /* Malloced string that needs to be freed */
             Token sColname;  /* Computed column name as a token */
 
+            assert( zName );
+            if( zTName && pSub
+             && sqlite3MatchSpanName(pSub->pEList->a[j].zSpan, 0, zTName, 0)==0
+            ){
+              continue;
+            }
+
             /* If a column is marked as 'hidden' (currently only possible
             ** for virtual tables), do not include it in the expanded
             ** result-set list.
@@ -3437,6 +3537,7 @@ static int selectExpander(Walker *pWalker, Select *p){
               assert(IsVirtual(pTab));
               continue;
             }
+            tableSeen = 1;
 
             if( i>0 && zTName==0 ){
               if( (pFrom->jointype & JT_NATURAL)!=0
@@ -3459,6 +3560,10 @@ static int selectExpander(Walker *pWalker, Select *p){
               Expr *pLeft;
               pLeft = sqlite3Expr(db, TK_ID, zTabName);
               pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
+              if( zSchemaName ){
+                pLeft = sqlite3Expr(db, TK_ID, zSchemaName);
+                pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr, 0);
+              }
               if( longNames ){
                 zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
                 zToFree = zColname;
@@ -3470,6 +3575,18 @@ static int selectExpander(Walker *pWalker, Select *p){
             sColname.z = zColname;
             sColname.n = sqlite3Strlen30(zColname);
             sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
+            if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
+              struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
+              if( pSub ){
+                pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan);
+                testcase( pX->zSpan==0 );
+              }else{
+                pX->zSpan = sqlite3MPrintf(db, "%s.%s.%s",
+                                           zSchemaName, zTabName, zColname);
+                testcase( pX->zSpan==0 );
+              }
+              pX->bSpanIsTab = 1;
+            }
             sqlite3DbFree(db, zToFree);
           }
         }
@@ -3522,10 +3639,13 @@ static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
 */
 static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
   Walker w;
-  w.xSelectCallback = selectExpander;
+  memset(&w, 0, sizeof(w));
+  w.xSelectCallback = convertCompoundSelectToSubquery;
   w.xExprCallback = exprWalkNoop;
   w.pParse = pParse;
   sqlite3WalkSelect(&w, pSelect);
+  w.xSelectCallback = selectExpander;
+  sqlite3WalkSelect(&w, pSelect);
 }
 
 
@@ -3580,9 +3700,11 @@ static int selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
 static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
 #ifndef SQLITE_OMIT_SUBQUERY
   Walker w;
+  memset(&w, 0, sizeof(w));
   w.xSelectCallback = selectAddSubqueryTypeInfo;
   w.xExprCallback = exprWalkNoop;
   w.pParse = pParse;
+  w.bSelectDepthFirst = 1;
   sqlite3WalkSelect(&w, pSelect);
 #endif
 }
@@ -3608,6 +3730,7 @@ void sqlite3SelectPrep(
   sqlite3 *db;
   if( NEVER(p==0) ) return;
   db = pParse->db;
+  if( db->mallocFailed ) return;
   if( p->selFlags & SF_HasTypeInfo ) return;
   sqlite3SelectExpand(pParse, p);
   if( pParse->nErr || db->mallocFailed ) return;
@@ -3992,7 +4115,7 @@ int sqlite3Select(
       pItem->addrFillSub = topAddr+1;
       VdbeNoopComment((v, "materialize %s", pItem->pTab->zName));
       if( pItem->isCorrelated==0 ){
-        /* If the subquery is no correlated and if we are not inside of
+        /* If the subquery is not correlated and if we are not inside of
         ** a trigger, then we only need to compute the value of the subquery
         ** once. */
         onceAddr = sqlite3CodeOnce(pParse);
@@ -4515,7 +4638,7 @@ int sqlite3Select(
         ** value of x, the only row required).
         **
         ** A special flag must be passed to sqlite3WhereBegin() to slightly
-        ** modify behaviour as follows:
+        ** modify behavior as follows:
         **
         **   + If the query is a "SELECT min(x)", then the loop coded by
         **     where.c should not iterate over any values with a NULL value
@@ -4527,11 +4650,17 @@ int sqlite3Select(
         **     Refer to code and comments in where.c for details.
         */
         ExprList *pMinMax = 0;
-        u8 flag = minMaxQuery(p);
+        u8 flag = WHERE_ORDERBY_NORMAL;
+        
+        assert( p->pGroupBy==0 );
+        assert( flag==0 );
+        if( p->pHaving==0 ){
+          flag = minMaxQuery(&sAggInfo, &pMinMax);
+        }
+        assert( flag==0 || (pMinMax!=0 && pMinMax->nExpr==1) );
+
         if( flag ){
-          assert( !ExprHasProperty(p->pEList->a[0].pExpr, EP_xIsSelect) );
-          assert( p->pEList->a[0].pExpr->x.pList->nExpr==1 );
-          pMinMax = sqlite3ExprListDup(db, p->pEList->a[0].pExpr->x.pList,0);
+          pMinMax = sqlite3ExprListDup(db, pMinMax, 0);
           pDel = pMinMax;
           if( pMinMax && !db->mallocFailed ){
             pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0;
@@ -4687,7 +4816,10 @@ void sqlite3ExplainSelect(Vdbe *pVdbe, Select *p){
     sqlite3ExplainPrintf(pVdbe, "(null-select)");
     return;
   }
-  while( p->pPrior ) p = p->pPrior;
+  while( p->pPrior ){
+    p->pPrior->pNext = p;
+    p = p->pPrior;
+  }
   sqlite3ExplainPush(pVdbe);
   while( p ){
     explainOneSelect(pVdbe, p);
diff --git a/lib/libsqlite3/src/sqlite.h.in b/lib/libsqlite3/src/sqlite.h.in
index 48f7381212b..6608823175d 100644
--- a/lib/libsqlite3/src/sqlite.h.in
+++ b/lib/libsqlite3/src/sqlite.h.in
@@ -283,7 +283,7 @@ typedef sqlite_uint64 sqlite3_uint64;
 ** [sqlite3_blob_close | close] all [BLOB handles], and 
 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
 ** with the [sqlite3] object prior to attempting to close the object.  ^If
-** sqlite3_close() is called on a [database connection] that still has
+** sqlite3_close_v2() is called on a [database connection] that still has
 ** outstanding [prepared statements], [BLOB handles], and/or
 ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
 ** of resources is deferred until all [prepared statements], [BLOB handles],
@@ -420,6 +420,8 @@ int sqlite3_exec(
 #define SQLITE_FORMAT      24   /* Auxiliary database format error */
 #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
 #define SQLITE_NOTADB      26   /* File opened that is not a database file */
+#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
+#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
 #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
 #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
 /* end-of-error-codes */
@@ -470,6 +472,7 @@ int sqlite3_exec(
 #define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
 #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
 #define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
+#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
 #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
 #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
@@ -478,7 +481,19 @@ int sqlite3_exec(
 #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
 #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
+#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
 #define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
+#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
+#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
+#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
+#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
+#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
+#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
+#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
+#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
+#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
+#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
+#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
 
 /*
 ** CAPI3REF: Flags For File Open Operations
@@ -718,6 +733,9 @@ struct sqlite3_io_methods {
   void (*xShmBarrier)(sqlite3_file*);
   int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
   /* Methods above are valid for version 2 */
+  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
+  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
+  /* Methods above are valid for version 3 */
   /* Additional methods may be added in future releases */
 };
 
@@ -854,7 +872,8 @@ struct sqlite3_io_methods {
 ** it is able to override built-in [PRAGMA] statements.
 **
 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
-** ^This file-control may be invoked by SQLite on the database file handle
+** ^The [SQLITE_FCNTL_BUSYHANDLER]
+** file-control may be invoked by SQLite on the database file handle
 ** shortly after it is opened in order to provide a custom VFS with access
 ** to the connections busy-handler callback. The argument is of type (void **)
 ** - an array of two (void *) values. The first (void *) actually points
@@ -865,13 +884,24 @@ struct sqlite3_io_methods {
 ** current operation.
 **
 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
-** ^Application can invoke this file-control to have SQLite generate a
+** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
+** to have SQLite generate a
 ** temporary filename using the same algorithm that is followed to generate
 ** temporary filenames for TEMP tables and other internal uses.  The
 ** argument should be a char** which will be filled with the filename
 ** written into memory obtained from [sqlite3_malloc()].  The caller should
 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
 **
+** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
+** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
+** maximum number of bytes that will be used for memory-mapped I/O.
+** The argument is a pointer to a value of type sqlite3_int64 that
+** is an advisory maximum number of bytes in the file to memory map.  The
+** pointer is overwritten with the old value.  The limit is not changed if
+** the value originally pointed to is negative, and so the current limit 
+** can be queried by passing in a pointer to a negative number.  This
+** file-control is used internally to implement [PRAGMA mmap_size].
+**
 ** </ul>
 */
 #define SQLITE_FCNTL_LOCKSTATE               1
@@ -890,6 +920,7 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_PRAGMA                 14
 #define SQLITE_FCNTL_BUSYHANDLER            15
 #define SQLITE_FCNTL_TEMPFILENAME           16
+#define SQLITE_FCNTL_MMAP_SIZE              18
 
 /*
 ** CAPI3REF: Mutex Handle
@@ -1556,7 +1587,9 @@ struct sqlite3_mem_methods {
 ** page cache implementation into that object.)^ </dd>
 **
 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
-** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
+** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
+** global [error log].
+** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
 ** function with a call signature of void(*)(void*,int,const char*), 
 ** and a pointer to void. ^If the function pointer is not NULL, it is
 ** invoked by [sqlite3_log()] to process each logging event.  ^If the
@@ -1602,12 +1635,12 @@ struct sqlite3_mem_methods {
 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
 ** <dd> These options are obsolete and should not be used by new code.
 ** They are retained for backwards compatibility but are now no-ops.
-** </dl>
+** </dd>
 **
 ** [[SQLITE_CONFIG_SQLLOG]]
 ** <dt>SQLITE_CONFIG_SQLLOG
 ** <dd>This option is only available if sqlite is compiled with the
-** SQLITE_ENABLE_SQLLOG pre-processor macro defined. The first argument should
+** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
 ** The second should be of type (void*). The callback is invoked by the library
 ** in three separate circumstances, identified by the value passed as the
@@ -1617,7 +1650,23 @@ struct sqlite3_mem_methods {
 ** fourth parameter is 1, then the SQL statement that the third parameter
 ** points to has just been executed. Or, if the fourth parameter is 2, then
 ** the connection being passed as the second parameter is being closed. The
-** third parameter is passed NULL In this case.
+** third parameter is passed NULL In this case.  An example of using this
+** configuration option can be seen in the "test_sqllog.c" source file in
+** the canonical SQLite source tree.</dd>
+**
+** [[SQLITE_CONFIG_MMAP_SIZE]]
+** <dt>SQLITE_CONFIG_MMAP_SIZE
+** <dd>SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
+** that are the default mmap size limit (the default setting for
+** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
+** The default setting can be overridden by each database connection using
+** either the [PRAGMA mmap_size] command, or by using the
+** [SQLITE_FCNTL_MMAP_SIZE] file control.  The maximum allowed mmap size
+** cannot be changed at run-time.  Nor may the maximum allowed mmap size
+** exceed the compile-time maximum mmap size set by the
+** [SQLITE_MAX_MMAP_SIZE] compile-time option.  
+** If either argument to this option is negative, then that argument is
+** changed to its compile-time default.
 ** </dl>
 */
 #define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
@@ -1641,6 +1690,7 @@ struct sqlite3_mem_methods {
 #define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
 #define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
+#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
 
 /*
 ** CAPI3REF: Database Connection Configuration Options
@@ -2474,6 +2524,9 @@ int sqlite3_set_authorizer(
 ** as each triggered subprogram is entered.  The callbacks for triggers
 ** contain a UTF-8 SQL comment that identifies the trigger.)^
 **
+** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
+** the length of [bound parameter] expansion in the output of sqlite3_trace().
+**
 ** ^The callback function registered by sqlite3_profile() is invoked
 ** as each SQL statement finishes.  ^The profile callback contains
 ** the original statement text and an estimate of wall-clock time
@@ -2665,7 +2718,7 @@ void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is 
 **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
 **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
-**     a URI filename, its value overrides any behaviour requested by setting
+**     a URI filename, its value overrides any behavior requested by setting
 **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
 ** </ul>
 **
@@ -3012,7 +3065,8 @@ int sqlite3_limit(sqlite3*, int id, int newVal);
 ** <li>
 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
-** statement and try to run it again.
+** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
+** retries will occur before sqlite3_step() gives up and returns an error.
 ** </li>
 **
 ** <li>
@@ -3216,6 +3270,9 @@ typedef struct sqlite3_context sqlite3_context;
 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
 **
 ** ^The third argument is the value to bind to the parameter.
+** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
+** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
+** is ignored and the end result is the same as sqlite3_bind_null().
 **
 ** ^(In those routines that have a fourth argument, its value is the
 ** number of bytes in the parameter.  To be clear: the value is the
@@ -3983,7 +4040,8 @@ SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
 SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
 SQLITE_DEPRECATED int sqlite3_global_recover(void);
 SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
-SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
+SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
+                      void*,sqlite3_int64);
 #endif
 
 /*
@@ -4063,14 +4121,17 @@ int sqlite3_value_numeric_type(sqlite3_value*);
 ** In those cases, sqlite3_aggregate_context() might be called for the
 ** first time from within xFinal().)^
 **
-** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
-** less than or equal to zero or if a memory allocate error occurs.
+** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 
+** when first called if N is less than or equal to zero or if a memory
+** allocate error occurs.
 **
 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
 ** determined by the N parameter on first successful call.  Changing the
 ** value of N in subsequent call to sqlite3_aggregate_context() within
 ** the same aggregate function instance will not resize the memory
-** allocation.)^
+** allocation.)^  Within the xFinal callback, it is customary to set
+** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 
+** pointless memory allocations occur.
 **
 ** ^SQLite automatically frees the memory allocated by 
 ** sqlite3_aggregate_context() when the aggregate query concludes.
@@ -4168,7 +4229,7 @@ void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
 ** the content before returning.
 **
 ** The typedef is necessary to work around problems in certain
-** C++ compilers.  See ticket #2191.
+** C++ compilers.
 */
 typedef void (*sqlite3_destructor_type)(void*);
 #define SQLITE_STATIC      ((sqlite3_destructor_type)0)
@@ -4967,11 +5028,20 @@ int sqlite3_table_column_metadata(
 ** ^This interface loads an SQLite extension library from the named file.
 **
 ** ^The sqlite3_load_extension() interface attempts to load an
-** SQLite extension library contained in the file zFile.
+** [SQLite extension] library contained in the file zFile.  If
+** the file cannot be loaded directly, attempts are made to load
+** with various operating-system specific extensions added.
+** So for example, if "samplelib" cannot be loaded, then names like
+** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
+** be tried also.
 **
 ** ^The entry point is zProc.
-** ^zProc may be 0, in which case the name of the entry point
-** defaults to "sqlite3_extension_init".
+** ^(zProc may be 0, in which case SQLite will try to come up with an
+** entry point name on its own.  It first tries "sqlite3_extension_init".
+** If that does not work, it constructs a name "sqlite3_X_init" where the
+** X is consists of the lower-case equivalent of all ASCII alphabetic
+** characters in the filename from the last "/" to the first following
+** "." and omitting any initial "lib".)^
 ** ^The sqlite3_load_extension() interface returns
 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
 ** ^If an error occurs and pzErrMsg is not 0, then the
@@ -4997,11 +5067,11 @@ int sqlite3_load_extension(
 ** CAPI3REF: Enable Or Disable Extension Loading
 **
 ** ^So as not to open security holes in older applications that are
-** unprepared to deal with extension loading, and as a means of disabling
-** extension loading while evaluating user-entered SQL, the following API
+** unprepared to deal with [extension loading], and as a means of disabling
+** [extension loading] while evaluating user-entered SQL, the following API
 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
 **
-** ^Extension loading is off by default. See ticket #1863.
+** ^Extension loading is off by default.
 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
 ** to turn extension loading on and call it with onoff==0 to turn
 ** it back off again.
@@ -5013,7 +5083,7 @@ int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
 **
 ** ^This interface causes the xEntryPoint() function to be invoked for
 ** each new [database connection] that is created.  The idea here is that
-** xEntryPoint() is the entry point for a statically linked SQLite extension
+** xEntryPoint() is the entry point for a statically linked [SQLite extension]
 ** that is to be automatically loaded into all new database connections.
 **
 ** ^(Even though the function prototype shows that xEntryPoint() takes
@@ -6364,7 +6434,7 @@ struct sqlite3_pcache_page {
 ** parameter to help it determined what action to take:
 **
 ** <table border=1 width=85% align=center>
-** <tr><th> createFlag <th> Behaviour when page is not already in cache
+** <tr><th> createFlag <th> Behavior when page is not already in cache
 ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
 **                 Otherwise return NULL.
@@ -6794,9 +6864,24 @@ int sqlite3_stricmp(const char *, const char *);
 int sqlite3_strnicmp(const char *, const char *, int);
 
 /*
+** CAPI3REF: String Globbing
+*
+** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
+** the glob pattern P, and it returns non-zero if string X does not match
+** the glob pattern P.  ^The definition of glob pattern matching used in
+** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
+** SQL dialect used by SQLite.  ^The sqlite3_strglob(P,X) function is case
+** sensitive.
+**
+** Note that this routine returns zero on a match and non-zero if the strings
+** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
+*/
+int sqlite3_strglob(const char *zGlob, const char *zStr);
+
+/*
 ** CAPI3REF: Error Logging Interface
 **
-** ^The [sqlite3_log()] interface writes a message into the error log
+** ^The [sqlite3_log()] interface writes a message into the [error log]
 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
 ** ^If logging is enabled, the zFormat string and subsequent arguments are
 ** used with [sqlite3_snprintf()] to generate the final output string.
diff --git a/lib/libsqlite3/src/sqlite3ext.h b/lib/libsqlite3/src/sqlite3ext.h
index 5abcde2c8f4..928bb3bad9d 100644
--- a/lib/libsqlite3/src/sqlite3ext.h
+++ b/lib/libsqlite3/src/sqlite3ext.h
@@ -236,6 +236,20 @@ struct sqlite3_api_routines {
   int (*blob_reopen)(sqlite3_blob*,sqlite3_int64);
   int (*vtab_config)(sqlite3*,int op,...);
   int (*vtab_on_conflict)(sqlite3*);
+  /* Version 3.7.16 and later */
+  int (*close_v2)(sqlite3*);
+  const char *(*db_filename)(sqlite3*,const char*);
+  int (*db_readonly)(sqlite3*,const char*);
+  int (*db_release_memory)(sqlite3*);
+  const char *(*errstr)(int);
+  int (*stmt_busy)(sqlite3_stmt*);
+  int (*stmt_readonly)(sqlite3_stmt*);
+  int (*stricmp)(const char*,const char*);
+  int (*uri_boolean)(const char*,const char*,int);
+  sqlite3_int64 (*uri_int64)(const char*,const char*,sqlite3_int64);
+  const char *(*uri_parameter)(const char*,const char*);
+  char *(*vsnprintf)(int,char*,const char*,va_list);
+  int (*wal_checkpoint_v2)(sqlite3*,const char*,int,int*,int*);
 };
 
 /*
@@ -439,9 +453,32 @@ struct sqlite3_api_routines {
 #define sqlite3_blob_reopen            sqlite3_api->blob_reopen
 #define sqlite3_vtab_config            sqlite3_api->vtab_config
 #define sqlite3_vtab_on_conflict       sqlite3_api->vtab_on_conflict
+/* Version 3.7.16 and later */
+#define sqlite3_close_v2               sqlite3_api->close_v2
+#define sqlite3_db_filename            sqlite3_api->db_filename
+#define sqlite3_db_readonly            sqlite3_api->db_readonly
+#define sqlite3_db_release_memory      sqlite3_api->db_release_memory
+#define sqlite3_errstr                 sqlite3_api->errstr
+#define sqlite3_stmt_busy              sqlite3_api->stmt_busy
+#define sqlite3_stmt_readonly          sqlite3_api->stmt_readonly
+#define sqlite3_stricmp                sqlite3_api->stricmp
+#define sqlite3_uri_boolean            sqlite3_api->uri_boolean
+#define sqlite3_uri_int64              sqlite3_api->uri_int64
+#define sqlite3_uri_parameter          sqlite3_api->uri_parameter
+#define sqlite3_uri_vsnprintf          sqlite3_api->vsnprintf
+#define sqlite3_wal_checkpoint_v2      sqlite3_api->wal_checkpoint_v2
 #endif /* SQLITE_CORE */
 
-#define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api = 0;
-#define SQLITE_EXTENSION_INIT2(v)  sqlite3_api = v;
+#ifndef SQLITE_CORE
+  /* This case when the file really is being compiled as a loadable 
+  ** extension */
+# define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;
+# define SQLITE_EXTENSION_INIT2(v)  sqlite3_api=v;
+#else
+  /* This case when the file is being statically linked into the 
+  ** application */
+# define SQLITE_EXTENSION_INIT1     /*no-op*/
+# define SQLITE_EXTENSION_INIT2(v)  (void)v; /* unused parameter */
+#endif
 
 #endif /* _SQLITE3EXT_H_ */
diff --git a/lib/libsqlite3/src/sqliteInt.h b/lib/libsqlite3/src/sqliteInt.h
index 2b58a808fb4..5950f237d9f 100644
--- a/lib/libsqlite3/src/sqliteInt.h
+++ b/lib/libsqlite3/src/sqliteInt.h
@@ -66,6 +66,10 @@
 # define _GNU_SOURCE
 #endif
 
+#if defined(__OpenBSD__) && !defined(_BSD_SOURCE)
+# define _BSD_SOURCE
+#endif
+
 /*
 ** Include standard header files as necessary
 */
@@ -118,11 +122,11 @@
 ** We support that for legacy.
 */
 #if !defined(SQLITE_THREADSAFE)
-#if defined(THREADSAFE)
-# define SQLITE_THREADSAFE THREADSAFE
-#else
-# define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
-#endif
+# if defined(THREADSAFE)
+#   define SQLITE_THREADSAFE THREADSAFE
+# else
+#   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
+# endif
 #endif
 
 /*
@@ -200,7 +204,8 @@
 **
 ** See also ticket #2741.
 */
-#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
+#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) \
+ && !defined(__APPLE__) && SQLITE_THREADSAFE
 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
 #endif
 
@@ -387,6 +392,7 @@
 */
 #ifndef SQLITE_TEMP_STORE
 # define SQLITE_TEMP_STORE 1
+# define SQLITE_TEMP_STORE_xc 1  /* Exclude from ctime.c */
 #endif
 
 /*
@@ -534,6 +540,49 @@ extern const int sqlite3one;
 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
 #endif
 
+/*
+** Disable MMAP on platforms where it is known to not work
+*/
+#if defined(__OpenBSD__) || defined(__QNXNTO__)
+# undef SQLITE_MAX_MMAP_SIZE
+# define SQLITE_MAX_MMAP_SIZE 0
+#endif
+
+/*
+** Default maximum size of memory used by memory-mapped I/O in the VFS
+*/
+#ifdef __APPLE__
+# include <TargetConditionals.h>
+# if TARGET_OS_IPHONE
+#   undef SQLITE_MAX_MMAP_SIZE
+#   define SQLITE_MAX_MMAP_SIZE 0
+# endif
+#endif
+#ifndef SQLITE_MAX_MMAP_SIZE
+# if defined(__linux__) \
+  || defined(_WIN32) \
+  || (defined(__APPLE__) && defined(__MACH__)) \
+  || defined(__sun)
+#   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */
+# else
+#   define SQLITE_MAX_MMAP_SIZE 0
+# endif
+# define SQLITE_MAX_MMAP_SIZE_xc 1 /* exclude from ctime.c */
+#endif
+
+/*
+** The default MMAP_SIZE is zero on all platforms.  Or, even if a larger
+** default MMAP_SIZE is specified at compile-time, make sure that it does
+** not exceed the maximum mmap size.
+*/
+#ifndef SQLITE_DEFAULT_MMAP_SIZE
+# define SQLITE_DEFAULT_MMAP_SIZE 0
+# define SQLITE_DEFAULT_MMAP_SIZE_xc 1  /* Exclude from ctime.c */
+#endif
+#if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
+# undef SQLITE_DEFAULT_MMAP_SIZE
+# define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE
+#endif
 
 /*
 ** An instance of the following structure is used to store the busy-handler
@@ -576,6 +625,11 @@ struct BusyHandler {
 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
 
 /*
+** Determine if the argument is a power of two
+*/
+#define IsPowerOfTwo(X) (((X)&((X)-1))==0)
+
+/*
 ** The following value as a destructor means to use sqlite3DbFree().
 ** The sqlite3DbFree() routine requires two parameters instead of the 
 ** one parameter that destructors normally want.  So we have to introduce 
@@ -824,6 +878,7 @@ struct sqlite3 {
   int nDb;                      /* Number of backends currently in use */
   int flags;                    /* Miscellaneous flags. See below */
   i64 lastRowid;                /* ROWID of most recent insert (see above) */
+  i64 szMmap;                   /* Default mmap_size setting */
   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
   int errCode;                  /* Most recent error code (SQLITE_*) */
   int errMask;                  /* & result codes with this before returning */
@@ -944,7 +999,7 @@ struct sqlite3 {
 #define SQLITE_SqlTrace       0x00000040  /* Debug print SQL as it executes */
 #define SQLITE_VdbeListing    0x00000080  /* Debug listings of VDBE programs */
 #define SQLITE_WriteSchema    0x00000100  /* OK to update SQLITE_MASTER */
-                         /*   0x00000200  Unused */
+#define SQLITE_VdbeAddopTrace 0x00000200  /* Trace sqlite3VdbeAddOp() calls */
 #define SQLITE_IgnoreChecks   0x00000400  /* Do not enforce check constraints */
 #define SQLITE_ReadUncommitted 0x0000800  /* For shared-cache mode */
 #define SQLITE_LegacyFileFmt  0x00001000  /* Create new databases in format 1 */
@@ -973,6 +1028,7 @@ struct sqlite3 {
 #define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
 #define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
 #define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
+#define SQLITE_Transitive     0x0200   /* Transitive constraints */
 #define SQLITE_AllOpts        0xffff   /* All optimizations */
 
 /*
@@ -1484,20 +1540,20 @@ struct UnpackedRecord {
 ** element.
 */
 struct Index {
-  char *zName;     /* Name of this index */
-  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
-  tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
-  Table *pTable;   /* The SQL table being indexed */
-  char *zColAff;   /* String defining the affinity of each column */
-  Index *pNext;    /* The next index associated with the same table */
-  Schema *pSchema; /* Schema containing this index */
-  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
-  char **azColl;   /* Array of collation sequence names for index */
-  int nColumn;     /* Number of columns in the table used by this index */
-  int tnum;        /* Page containing root of this index in database file */
-  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
-  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
-  u8 bUnordered;   /* Use this index for == or IN queries only */
+  char *zName;             /* Name of this index */
+  int *aiColumn;           /* Which columns are used by this index.  1st is 0 */
+  tRowcnt *aiRowEst;       /* From ANALYZE: Est. rows selected by each column */
+  Table *pTable;           /* The SQL table being indexed */
+  char *zColAff;           /* String defining the affinity of each column */
+  Index *pNext;            /* The next index associated with the same table */
+  Schema *pSchema;         /* Schema containing this index */
+  u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
+  char **azColl;           /* Array of collation sequence names for index */
+  int tnum;                /* DB Page containing root of this index */
+  u16 nColumn;             /* Number of columns in table used by this index */
+  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
+  unsigned autoIndex:2;    /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
+  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
 #ifdef SQLITE_ENABLE_STAT3
   int nSample;             /* Number of elements in aSample[] */
   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
@@ -1771,18 +1827,27 @@ struct Expr {
 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
 ** also be used as the argument to a function, in which case the a.zName
 ** field is not used.
+**
+** By default the Expr.zSpan field holds a human-readable description of
+** the expression that is used in the generation of error messages and
+** column labels.  In this case, Expr.zSpan is typically the text of a
+** column expression as it exists in a SELECT statement.  However, if
+** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name
+** of the result column in the form: DATABASE.TABLE.COLUMN.  This later
+** form is used for name resolution with nested FROM clauses.
 */
 struct ExprList {
   int nExpr;             /* Number of expressions on the list */
   int iECursor;          /* VDBE Cursor associated with this ExprList */
   struct ExprList_item { /* For each expression in the list */
-    Expr *pExpr;           /* The list of expressions */
-    char *zName;           /* Token associated with this expression */
-    char *zSpan;           /* Original text of the expression */
-    u8 sortOrder;          /* 1 for DESC or 0 for ASC */
-    u8 done;               /* A flag to indicate when processing is finished */
-    u16 iOrderByCol;       /* For ORDER BY, column number in result set */
-    u16 iAlias;            /* Index into Parse.aAlias[] for zName */
+    Expr *pExpr;            /* The list of expressions */
+    char *zName;            /* Token associated with this expression */
+    char *zSpan;            /* Original text of the expression */
+    u8 sortOrder;           /* 1 for DESC or 0 for ASC */
+    unsigned done :1;       /* A flag to indicate when processing is finished */
+    unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
+    u16 iOrderByCol;        /* For ORDER BY, column number in result set */
+    u16 iAlias;             /* Index into Parse.aAlias[] for zName */
   } *a;                  /* Alloc a power of two greater or equal to nExpr */
 };
 
@@ -1950,6 +2015,7 @@ struct WhereLevel {
       struct InLoop {
         int iCur;              /* The VDBE cursor used by this IN operator */
         int addrInTop;         /* Top of the IN loop */
+        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
       } *aInLoop;           /* Information about each nested IN operator */
     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
     Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
@@ -2049,6 +2115,8 @@ struct NameContext {
 #define NC_HasAgg    0x02    /* One or more aggregate functions seen */
 #define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
 #define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
+#define NC_AsMaybe   0x10    /* Resolve to AS terms of the result set only
+                             ** if no other resolution is available */
 
 /*
 ** An instance of the following structure contains all information
@@ -2102,6 +2170,7 @@ struct Select {
 #define SF_UseSorter       0x0040  /* Sort using a sorter */
 #define SF_Values          0x0080  /* Synthesized from VALUES clause */
 #define SF_Materialize     0x0100  /* Force materialization of views */
+#define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
 
 
 /*
@@ -2483,6 +2552,8 @@ struct Sqlite3Config {
   void *pHeap;                      /* Heap storage space */
   int nHeap;                        /* Size of pHeap[] */
   int mnReq, mxReq;                 /* Min and max heap requests sizes */
+  sqlite3_int64 szMmap;             /* mmap() space per open file */
+  sqlite3_int64 mxMmap;             /* Maximum value for szMmap */
   void *pScratch;                   /* Scratch memory */
   int szScratch;                    /* Size of each scratch buffer */
   int nScratch;                     /* Number of scratch buffers */
@@ -2517,6 +2588,7 @@ struct Walker {
   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
   Parse *pParse;                            /* Parser context.  */
   int walkerDepth;                          /* Number of subqueries */
+  u8 bSelectDepthFirst;                     /* Do subqueries first */
   union {                                   /* Extra data for callback */
     NameContext *pNC;                          /* Naming context */
     int i;                                     /* Integer value */
@@ -2814,13 +2886,13 @@ Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
 void sqlite3DropIndex(Parse*, SrcList*, int);
 int sqlite3Select(Parse*, Select*, SelectDest*);
 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
-                         Expr*,ExprList*,int,Expr*,Expr*);
+                         Expr*,ExprList*,u16,Expr*,Expr*);
 void sqlite3SelectDelete(sqlite3*, Select*);
 Table *sqlite3SrcListLookup(Parse*, SrcList*);
 int sqlite3IsReadOnly(Parse*, Table*, int);
 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
-Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
+Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
 #endif
 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
@@ -2888,7 +2960,7 @@ int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
 void sqlite3BeginWriteOperation(Parse*, int, int);
 void sqlite3MultiWrite(Parse*);
 void sqlite3MayAbort(Parse*);
-void sqlite3HaltConstraint(Parse*, int, char*, int);
+void sqlite3HaltConstraint(Parse*, int, int, char*, int);
 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
@@ -3001,8 +3073,11 @@ int sqlite3VarintLen(u64 v);
 **     x = putVarint32( A, B );
 **
 */
-#define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
-#define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
+#define getVarint32(A,B)  \
+  (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))
+#define putVarint32(A,B)  \
+  (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\
+  sqlite3PutVarint32((A),(B)))
 #define getVarint    sqlite3GetVarint
 #define putVarint    sqlite3PutVarint
 
@@ -3017,6 +3092,12 @@ void sqlite3Error(sqlite3*, int, const char*,...);
 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
 u8 sqlite3HexToInt(int h);
 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
+
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) || \
+    defined(SQLITE_DEBUG_OS_TRACE)
+const char *sqlite3ErrName(int);
+#endif
+
 const char *sqlite3ErrStr(int);
 int sqlite3ReadSchema(Parse *pParse);
 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
@@ -3071,6 +3152,7 @@ void sqlite3NestedParse(Parse*, const char*, ...);
 void sqlite3ExpirePreparedStatements(sqlite3*);
 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
+int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
 int sqlite3ResolveExprNames(NameContext*, Expr*);
 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
@@ -3209,8 +3291,10 @@ const char *sqlite3JournalModename(int);
 #endif
 #ifndef SQLITE_OMIT_FOREIGN_KEY
   void sqlite3FkDelete(sqlite3 *, Table*);
+  int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);
 #else
   #define sqlite3FkDelete(a,b)
+  #define sqlite3FkLocateIndex(a,b,c,d,e)
 #endif
 
 
@@ -3235,7 +3319,8 @@ const char *sqlite3JournalModename(int);
 
 #define IN_INDEX_ROWID           1
 #define IN_INDEX_EPH             2
-#define IN_INDEX_INDEX           3
+#define IN_INDEX_INDEX_ASC       3
+#define IN_INDEX_INDEX_DESC      4
 int sqlite3FindInIndex(Parse *, Expr *, int*);
 
 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
diff --git a/lib/libsqlite3/src/tclsqlite.c b/lib/libsqlite3/src/tclsqlite.c
index 57dab85d4b5..f1bb2921da0 100644
--- a/lib/libsqlite3/src/tclsqlite.c
+++ b/lib/libsqlite3/src/tclsqlite.c
@@ -1005,7 +1005,7 @@ static int DbTransPostCmd(
       /* This is a tricky scenario to handle. The most likely cause of an
       ** error is that the exec() above was an attempt to commit the 
       ** top-level transaction that returned SQLITE_BUSY. Or, less likely,
-      ** that an IO-error has occured. In either case, throw a Tcl exception
+      ** that an IO-error has occurred. In either case, throw a Tcl exception
       ** and try to rollback the transaction.
       **
       ** But it could also be that the user executed one or more BEGIN, 
@@ -3671,6 +3671,7 @@ static void init_all(Tcl_Interp *interp){
     extern int Sqlitetestschema_Init(Tcl_Interp*);
     extern int Sqlitetestsse_Init(Tcl_Interp*);
     extern int Sqlitetesttclvar_Init(Tcl_Interp*);
+    extern int Sqlitetestfs_Init(Tcl_Interp*);
     extern int SqlitetestThread_Init(Tcl_Interp*);
     extern int SqlitetestOnefile_Init();
     extern int SqlitetestOsinst_Init(Tcl_Interp*);
@@ -3682,8 +3683,6 @@ static void init_all(Tcl_Interp *interp){
     extern int Sqlitemultiplex_Init(Tcl_Interp*);
     extern int SqliteSuperlock_Init(Tcl_Interp*);
     extern int SqlitetestSyscall_Init(Tcl_Interp*);
-    extern int Sqlitetestfuzzer_Init(Tcl_Interp*);
-    extern int Sqlitetestwholenumber_Init(Tcl_Interp*);
 
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
     extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
@@ -3714,6 +3713,7 @@ static void init_all(Tcl_Interp *interp){
     Sqlitetest_mutex_Init(interp);
     Sqlitetestschema_Init(interp);
     Sqlitetesttclvar_Init(interp);
+    Sqlitetestfs_Init(interp);
     SqlitetestThread_Init(interp);
     SqlitetestOnefile_Init(interp);
     SqlitetestOsinst_Init(interp);
@@ -3725,8 +3725,6 @@ static void init_all(Tcl_Interp *interp){
     Sqlitemultiplex_Init(interp);
     SqliteSuperlock_Init(interp);
     SqlitetestSyscall_Init(interp);
-    Sqlitetestfuzzer_Init(interp);
-    Sqlitetestwholenumber_Init(interp);
 
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
     Sqlitetestfts3_Init(interp);
diff --git a/lib/libsqlite3/src/test1.c b/lib/libsqlite3/src/test1.c
index bb8d186c121..a638e480add 100644
--- a/lib/libsqlite3/src/test1.c
+++ b/lib/libsqlite3/src/test1.c
@@ -113,64 +113,8 @@ int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){
   return TCL_OK;
 }
 
-
-const char *sqlite3TestErrorName(int rc){
-  const char *zName = 0;
-  switch( rc ){
-    case SQLITE_OK:                  zName = "SQLITE_OK";                break;
-    case SQLITE_ERROR:               zName = "SQLITE_ERROR";             break;
-    case SQLITE_INTERNAL:            zName = "SQLITE_INTERNAL";          break;
-    case SQLITE_PERM:                zName = "SQLITE_PERM";              break;
-    case SQLITE_ABORT:               zName = "SQLITE_ABORT";             break;
-    case SQLITE_BUSY:                zName = "SQLITE_BUSY";              break;
-    case SQLITE_LOCKED:              zName = "SQLITE_LOCKED";            break;
-    case SQLITE_LOCKED_SHAREDCACHE:  zName = "SQLITE_LOCKED_SHAREDCACHE";break;
-    case SQLITE_NOMEM:               zName = "SQLITE_NOMEM";             break;
-    case SQLITE_READONLY:            zName = "SQLITE_READONLY";          break;
-    case SQLITE_INTERRUPT:           zName = "SQLITE_INTERRUPT";         break;
-    case SQLITE_IOERR:               zName = "SQLITE_IOERR";             break;
-    case SQLITE_CORRUPT:             zName = "SQLITE_CORRUPT";           break;
-    case SQLITE_NOTFOUND:            zName = "SQLITE_NOTFOUND";          break;
-    case SQLITE_FULL:                zName = "SQLITE_FULL";              break;
-    case SQLITE_CANTOPEN:            zName = "SQLITE_CANTOPEN";          break;
-    case SQLITE_PROTOCOL:            zName = "SQLITE_PROTOCOL";          break;
-    case SQLITE_EMPTY:               zName = "SQLITE_EMPTY";             break;
-    case SQLITE_SCHEMA:              zName = "SQLITE_SCHEMA";            break;
-    case SQLITE_TOOBIG:              zName = "SQLITE_TOOBIG";            break;
-    case SQLITE_CONSTRAINT:          zName = "SQLITE_CONSTRAINT";        break;
-    case SQLITE_MISMATCH:            zName = "SQLITE_MISMATCH";          break;
-    case SQLITE_MISUSE:              zName = "SQLITE_MISUSE";            break;
-    case SQLITE_NOLFS:               zName = "SQLITE_NOLFS";             break;
-    case SQLITE_AUTH:                zName = "SQLITE_AUTH";              break;
-    case SQLITE_FORMAT:              zName = "SQLITE_FORMAT";            break;
-    case SQLITE_RANGE:               zName = "SQLITE_RANGE";             break;
-    case SQLITE_NOTADB:              zName = "SQLITE_NOTADB";            break;
-    case SQLITE_ROW:                 zName = "SQLITE_ROW";               break;
-    case SQLITE_DONE:                zName = "SQLITE_DONE";              break;
-    case SQLITE_IOERR_READ:          zName = "SQLITE_IOERR_READ";        break;
-    case SQLITE_IOERR_SHORT_READ:    zName = "SQLITE_IOERR_SHORT_READ";  break;
-    case SQLITE_IOERR_WRITE:         zName = "SQLITE_IOERR_WRITE";       break;
-    case SQLITE_IOERR_FSYNC:         zName = "SQLITE_IOERR_FSYNC";       break;
-    case SQLITE_IOERR_DIR_FSYNC:     zName = "SQLITE_IOERR_DIR_FSYNC";   break;
-    case SQLITE_IOERR_TRUNCATE:      zName = "SQLITE_IOERR_TRUNCATE";    break;
-    case SQLITE_IOERR_FSTAT:         zName = "SQLITE_IOERR_FSTAT";       break;
-    case SQLITE_IOERR_UNLOCK:        zName = "SQLITE_IOERR_UNLOCK";      break;
-    case SQLITE_IOERR_RDLOCK:        zName = "SQLITE_IOERR_RDLOCK";      break;
-    case SQLITE_IOERR_DELETE:        zName = "SQLITE_IOERR_DELETE";      break;
-    case SQLITE_IOERR_BLOCKED:       zName = "SQLITE_IOERR_BLOCKED";     break;
-    case SQLITE_IOERR_NOMEM:         zName = "SQLITE_IOERR_NOMEM";       break;
-    case SQLITE_IOERR_ACCESS:        zName = "SQLITE_IOERR_ACCESS";      break;
-    case SQLITE_IOERR_CHECKRESERVEDLOCK:
-                               zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
-    case SQLITE_IOERR_LOCK:          zName = "SQLITE_IOERR_LOCK";        break;
-    case SQLITE_CORRUPT_VTAB:        zName = "SQLITE_CORRUPT_VTAB";      break;
-    case SQLITE_READONLY_RECOVERY:   zName = "SQLITE_READONLY_RECOVERY"; break;
-    case SQLITE_READONLY_CANTLOCK:   zName = "SQLITE_READONLY_CANTLOCK"; break;
-    default:                         zName = "SQLITE_Unknown";           break;
-  }
-  return zName;
-}
-#define t1ErrorName sqlite3TestErrorName
+extern const char *sqlite3ErrName(int);
+#define t1ErrorName sqlite3ErrName
 
 /*
 ** Convert an sqlite3_stmt* into an sqlite3*.  This depends on the
@@ -738,6 +682,30 @@ static int sqlite_test_close(
 }
 
 /*
+** Usage:  sqlite3_close_v2 DB
+**
+** Closes the database opened by sqlite3_open.
+*/
+static int sqlite_test_close_v2(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite3 *db;
+  int rc;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " FILENAME\"", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
+  rc = sqlite3_close_v2(db);
+  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
+  return TCL_OK;
+}
+
+/*
 ** Implementation of the x_coalesce() function.
 ** Return the first argument non-NULL argument.
 */
@@ -1715,7 +1683,7 @@ static int test_blob_read(
   if( rc==SQLITE_OK ){
     Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(zBuf, nByte));
   }else{
-    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   }
   Tcl_Free((char *)zBuf);
 
@@ -1765,7 +1733,7 @@ static int test_blob_write(
   }
   rc = sqlite3_blob_write(pBlob, zBuf, nBuf, iOffset);
   if( rc!=SQLITE_OK ){
-    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   }
 
   return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
@@ -1791,7 +1759,7 @@ static int test_blob_reopen(
 
   rc = sqlite3_blob_reopen(pBlob, iRowid);
   if( rc!=SQLITE_OK ){
-    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   }
 
   return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
@@ -2001,7 +1969,7 @@ static int test_create_function_v2(
   );
   if( rc!=SQLITE_OK ){
     Tcl_ResetResult(interp);
-    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -2677,7 +2645,7 @@ static int test_collate(
   if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
   
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -3235,7 +3203,7 @@ static int test_bind_text(
   rc = sqlite3_bind_text(pStmt, idx, value, bytes, SQLITE_TRANSIENT);
   if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
 
@@ -3283,7 +3251,7 @@ static int test_bind_text16(
   rc = sqlite3_bind_text16(pStmt, idx, (void *)value, bytes, xDel);
   if( sqlite3TestErrCode(interp, StmtToDb(pStmt), rc) ) return TCL_ERROR;
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
 
@@ -4557,7 +4525,7 @@ static int test_busy_timeout(
   if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
   if( Tcl_GetInt(interp, argv[2], &ms) ) return TCL_ERROR;
   rc = sqlite3_busy_timeout(db, ms);
-  Tcl_AppendResult(interp, sqlite3TestErrorName(rc), 0);
+  Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
   return TCL_OK;
 }
 
@@ -5078,7 +5046,7 @@ static int file_control_chunksize_test(
 
   rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_CHUNK_SIZE, (void *)&nSize);
   if( rc ){
-    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -5115,7 +5083,7 @@ static int file_control_sizehint_test(
 
   rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_SIZE_HINT, (void *)&nSize);
   if( rc ){
-    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -5659,7 +5627,7 @@ static void xLogcallback(void *unused, int err, char *zMsg){
   Tcl_Obj *pNew = Tcl_DuplicateObj(logcallback.pObj);
   Tcl_IncrRefCount(pNew);
   Tcl_ListObjAppendElement(
-      0, pNew, Tcl_NewStringObj(sqlite3TestErrorName(err), -1)
+      0, pNew, Tcl_NewStringObj(sqlite3ErrName(err), -1)
   );
   Tcl_ListObjAppendElement(0, pNew, Tcl_NewStringObj(zMsg, -1));
   Tcl_EvalObjEx(logcallback.pInterp, pNew, TCL_EVAL_GLOBAL|TCL_EVAL_DIRECT);
@@ -5831,6 +5799,31 @@ static int test_test_control(
   return TCL_OK;
 }
 
+#if SQLITE_OS_UNIX
+#include <sys/time.h>
+#include <sys/resource.h>
+
+static int test_getrusage(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  char buf[1024];
+  struct rusage r;
+  memset(&r, 0, sizeof(r));
+  getrusage(RUSAGE_SELF, &r);
+
+  sprintf(buf, "ru_utime=%d.%06d ru_stime=%d.%06d ru_minflt=%d ru_majflt=%d", 
+    (int)r.ru_utime.tv_sec, (int)r.ru_utime.tv_usec, 
+    (int)r.ru_stime.tv_sec, (int)r.ru_stime.tv_usec, 
+    (int)r.ru_minflt, (int)r.ru_majflt
+  );
+  Tcl_SetObjResult(interp, Tcl_NewStringObj(buf, -1));
+  return TCL_OK;
+}
+#endif
+
 #if SQLITE_OS_WIN
 /*
 ** Information passed from the main thread into the windows file locker
@@ -6002,6 +5995,69 @@ static int optimization_control(
   return TCL_OK;
 }
 
+typedef struct sqlite3_api_routines sqlite3_api_routines;
+/*
+**     load_static_extension DB NAME ...
+**
+** Load one or more statically linked extensions.
+*/
+static int tclLoadStaticExtensionCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  extern int sqlite3_amatch_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_closure_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_fuzzer_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_ieee_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_nextchar_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_regexp_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_spellfix_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_wholenumber_init(sqlite3*,char**,const sqlite3_api_routines*);
+  static const struct {
+    const char *zExtName;
+    int (*pInit)(sqlite3*,char**,const sqlite3_api_routines*);
+  } aExtension[] = {
+    { "amatch",                sqlite3_amatch_init               },
+    { "closure",               sqlite3_closure_init              },
+    { "fuzzer",                sqlite3_fuzzer_init               },
+    { "ieee754",               sqlite3_ieee_init                 },
+    { "nextchar",              sqlite3_nextchar_init             },
+    { "regexp",                sqlite3_regexp_init               },
+    { "spellfix",              sqlite3_spellfix_init             },
+    { "wholenumber",           sqlite3_wholenumber_init          },
+  };
+  sqlite3 *db;
+  const char *zName;
+  int i, j, rc;
+  char *zErrMsg = 0;
+  if( objc<3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB NAME ...");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  for(j=2; j<objc; j++){
+    zName = Tcl_GetString(objv[j]);
+    for(i=0; i<ArraySize(aExtension); i++){
+      if( strcmp(zName, aExtension[i].zExtName)==0 ) break;
+    }
+    if( i>=ArraySize(aExtension) ){
+      Tcl_AppendResult(interp, "no such extension: ", zName, (char*)0);
+      return TCL_ERROR;
+    }
+    rc = aExtension[i].pInit(db, &zErrMsg, 0);
+    if( rc!=SQLITE_OK || zErrMsg ){
+      Tcl_AppendResult(interp, "initialization of ", zName, " failed: ", zErrMsg,
+                       (char*)0);
+      sqlite3_free(zErrMsg);
+      return TCL_ERROR;
+    }
+  }
+  return TCL_OK;
+}
+
+
 /*
 ** Register commands with the TCL interpreter.
 */
@@ -6045,6 +6101,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
      { "sqlite3_get_table_printf",      (Tcl_CmdProc*)test_get_table_printf },
 #endif
      { "sqlite3_close",                 (Tcl_CmdProc*)sqlite_test_close     },
+     { "sqlite3_close_v2",              (Tcl_CmdProc*)sqlite_test_close_v2  },
      { "sqlite3_create_function",       (Tcl_CmdProc*)test_create_function  },
      { "sqlite3_create_aggregate",      (Tcl_CmdProc*)test_create_aggregate },
      { "sqlite_register_test_function", (Tcl_CmdProc*)test_register_func    },
@@ -6220,6 +6277,10 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
      { "print_explain_query_plan", test_print_eqp, 0  },
 #endif
      { "sqlite3_test_control", test_test_control },
+#if SQLITE_OS_UNIX
+     { "getrusage", test_getrusage },
+#endif
+     { "load_static_extension", tclLoadStaticExtensionCmd },
   };
   static int bitmask_size = sizeof(Bitmask)*8;
   int i;
@@ -6236,7 +6297,6 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
 #ifdef SQLITE_DEBUG
   extern int sqlite3WhereTrace;
   extern int sqlite3OSTrace;
-  extern int sqlite3VdbeAddopTrace;
   extern int sqlite3WalTrace;
 #endif
 #ifdef SQLITE_TEST
@@ -6299,8 +6359,6 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
       (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
 #endif
 #ifdef SQLITE_DEBUG
-  Tcl_LinkVar(interp, "sqlite_addop_trace",
-      (char*)&sqlite3VdbeAddopTrace, TCL_LINK_INT);
   Tcl_LinkVar(interp, "sqlite_where_trace",
       (char*)&sqlite3WhereTrace, TCL_LINK_INT);
   Tcl_LinkVar(interp, "sqlite_os_trace",
diff --git a/lib/libsqlite3/src/test2.c b/lib/libsqlite3/src/test2.c
index 8acdf6f4efe..d130e9d01b7 100644
--- a/lib/libsqlite3/src/test2.c
+++ b/lib/libsqlite3/src/test2.c
@@ -19,35 +19,7 @@
 #include <string.h>
 #include <ctype.h>
 
-/*
-** Interpret an SQLite error number
-*/
-static char *errorName(int rc){
-  char *zName;
-  switch( rc ){
-    case SQLITE_OK:         zName = "SQLITE_OK";          break;
-    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
-    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
-    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
-    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
-    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
-    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
-    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
-    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
-    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
-    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
-    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
-    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
-    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
-    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
-    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
-    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
-    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
-    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
-    default:                zName = "SQLITE_Unknown";     break;
-  }
-  return zName;
-}
+extern const char *sqlite3ErrName(int);
 
 /*
 ** Page size and reserved size used for testing.
@@ -87,7 +59,7 @@ static int pager_open(
       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_MAIN_DB,
       pager_test_reiniter);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   sqlite3PagerSetCachesize(pPager, nPage);
@@ -119,7 +91,7 @@ static int pager_close(
   pPager = sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3PagerClose(pPager);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -146,7 +118,7 @@ static int pager_rollback(
   pPager = sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3PagerRollback(pPager);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -173,12 +145,12 @@ static int pager_commit(
   pPager = sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3PagerCommitPhaseOne(pPager, 0, 0);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   rc = sqlite3PagerCommitPhaseTwo(pPager);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -205,7 +177,7 @@ static int pager_stmt_begin(
   pPager = sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3PagerOpenSavepoint(pPager, 1);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -233,7 +205,7 @@ static int pager_stmt_rollback(
   rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, 0);
   sqlite3PagerSavepoint(pPager, SAVEPOINT_RELEASE, 0);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -260,7 +232,7 @@ static int pager_stmt_commit(
   pPager = sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_RELEASE, 0);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -353,7 +325,7 @@ static int page_get(
     rc = sqlite3PagerGet(pPager, pgno, &pPage);
   }
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   sqlite3_snprintf(sizeof(zBuf),zBuf,"%p",pPage);
@@ -507,7 +479,7 @@ static int page_write(
   pPage = (DbPage *)sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3PagerWrite(pPage);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   pData = sqlite3PagerGetData(pPage);
@@ -556,7 +528,7 @@ static int fake_big_file(
       (SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_DB), 0
   );
   if( rc ){
-    Tcl_AppendResult(interp, "open failed: ", errorName(rc), 0);
+    Tcl_AppendResult(interp, "open failed: ", sqlite3ErrName(rc), 0);
     sqlite3_free(zFile);
     return TCL_ERROR;
   }
@@ -566,7 +538,7 @@ static int fake_big_file(
   sqlite3OsCloseFree(fd);
   sqlite3_free(zFile);
   if( rc ){
-    Tcl_AppendResult(interp, "write failed: ", errorName(rc), 0);
+    Tcl_AppendResult(interp, "write failed: ", sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
diff --git a/lib/libsqlite3/src/test3.c b/lib/libsqlite3/src/test3.c
index e460c42e46c..e3ed310c810 100644
--- a/lib/libsqlite3/src/test3.c
+++ b/lib/libsqlite3/src/test3.c
@@ -19,31 +19,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-/*
-** Interpret an SQLite error number
-*/
-static char *errorName(int rc){
-  char *zName;
-  switch( rc ){
-    case SQLITE_OK:         zName = "SQLITE_OK";          break;
-    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
-    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
-    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
-    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
-    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
-    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
-    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
-    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
-    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
-    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
-    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
-    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
-    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
-    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
-    default:                zName = "SQLITE_Unknown";     break;
-  }
-  return zName;
-}
+extern const char *sqlite3ErrName(int);
 
 /*
 ** A bogus sqlite3 connection structure for use in the btree
@@ -89,7 +65,7 @@ static int btree_open(
      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_MAIN_DB);
   sqlite3_free(zFilename);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   sqlite3BtreeSetCacheSize(pBt, nCache);
@@ -119,7 +95,7 @@ static int btree_close(
   pBt = sqlite3TestTextToPtr(argv[1]);
   rc = sqlite3BtreeClose(pBt);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   nRefSqlite3--;
@@ -156,7 +132,7 @@ static int btree_begin_transaction(
   rc = sqlite3BtreeBeginTrans(pBt, 1);
   sqlite3BtreeLeave(pBt);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -250,7 +226,7 @@ static int btree_cursor(
   sqlite3BtreeLeave(pBt);
   if( rc ){
     ckfree((char *)pCur);
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   sqlite3_snprintf(sizeof(zBuf), zBuf,"%p", pCur);
@@ -285,7 +261,7 @@ static int btree_close_cursor(
   sqlite3BtreeLeave(pBt);
   ckfree((char *)pCur);
   if( rc ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   return SQLITE_OK;
@@ -319,7 +295,7 @@ static int btree_next(
   rc = sqlite3BtreeNext(pCur, &res);
   sqlite3BtreeLeave(pCur->pBtree);
   if( rc ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
@@ -354,7 +330,7 @@ static int btree_first(
   rc = sqlite3BtreeFirst(pCur, &res);
   sqlite3BtreeLeave(pCur->pBtree);
   if( rc ){
-    Tcl_AppendResult(interp, errorName(rc), 0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);
     return TCL_ERROR;
   }
   sqlite3_snprintf(sizeof(zBuf),zBuf,"%d",res);
diff --git a/lib/libsqlite3/src/test4.c b/lib/libsqlite3/src/test4.c
index 5b4c5a1c178..a6375c7cc40 100644
--- a/lib/libsqlite3/src/test4.c
+++ b/lib/libsqlite3/src/test4.c
@@ -20,6 +20,8 @@
 #include <sched.h>
 #include <ctype.h>
 
+extern const char *sqlite3ErrName(int);
+
 /*
 ** Each thread is controlled by an instance of the following
 ** structure.
@@ -372,34 +374,7 @@ static int tcl_thread_result(
     return TCL_ERROR;
   }
   thread_wait(&threadset[i]);
-  switch( threadset[i].rc ){
-    case SQLITE_OK:         zName = "SQLITE_OK";          break;
-    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
-    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
-    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
-    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
-    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
-    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
-    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
-    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
-    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
-    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
-    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
-    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
-    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
-    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
-    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
-    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
-    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
-    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
-    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
-    case SQLITE_AUTH:       zName = "SQLITE_AUTH";        break;
-    case SQLITE_FORMAT:     zName = "SQLITE_FORMAT";      break;
-    case SQLITE_RANGE:      zName = "SQLITE_RANGE";       break;
-    case SQLITE_ROW:        zName = "SQLITE_ROW";         break;
-    case SQLITE_DONE:       zName = "SQLITE_DONE";        break;
-    default:                zName = "SQLITE_Unknown";     break;
-  }
+  zName = sqlite3ErrName(threadset[i].rc);
   Tcl_AppendResult(interp, zName, 0);
   return TCL_OK;
 }
diff --git a/lib/libsqlite3/src/test6.c b/lib/libsqlite3/src/test6.c
index f511be9def8..c151ea42989 100644
--- a/lib/libsqlite3/src/test6.c
+++ b/lib/libsqlite3/src/test6.c
@@ -87,7 +87,7 @@ typedef struct WriteBuffer WriteBuffer;
 **   an aligned write() of an integer number of 512 byte regions, then
 **   option (3) above is never selected. Instead, each 512 byte region
 **   is either correctly written or left completely untouched. Similar
-**   logic governs the behaviour if any of the other ATOMICXXX flags
+**   logic governs the behavior if any of the other ATOMICXXX flags
 **   is set.
 **
 **   If either the IOCAP_SAFEAPPEND or IOCAP_SEQUENTIAL flags are set
diff --git a/lib/libsqlite3/src/test7.c b/lib/libsqlite3/src/test7.c
index 852cd1db5e8..3cd4a224d7e 100644
--- a/lib/libsqlite3/src/test7.c
+++ b/lib/libsqlite3/src/test7.c
@@ -376,6 +376,8 @@ static int tcl_client_colname(
   return TCL_OK;
 }
 
+extern const char *sqlite3ErrName(int);
+
 /*
 ** Usage: client_result  ID
 **
@@ -403,34 +405,7 @@ static int tcl_client_result(
     return TCL_ERROR;
   }
   client_wait(&threadset[i]);
-  switch( threadset[i].rc ){
-    case SQLITE_OK:         zName = "SQLITE_OK";          break;
-    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
-    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
-    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
-    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
-    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
-    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
-    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
-    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
-    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
-    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
-    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
-    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
-    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
-    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
-    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
-    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
-    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
-    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
-    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
-    case SQLITE_AUTH:       zName = "SQLITE_AUTH";        break;
-    case SQLITE_FORMAT:     zName = "SQLITE_FORMAT";      break;
-    case SQLITE_RANGE:      zName = "SQLITE_RANGE";       break;
-    case SQLITE_ROW:        zName = "SQLITE_ROW";         break;
-    case SQLITE_DONE:       zName = "SQLITE_DONE";        break;
-    default:                zName = "SQLITE_Unknown";     break;
-  }
+  zName = sqlite3ErrName(threadset[i].rc);
   Tcl_AppendResult(interp, zName, 0);
   return TCL_OK;
 }
diff --git a/lib/libsqlite3/src/test8.c b/lib/libsqlite3/src/test8.c
index 53cb149a04b..c5739332d46 100644
--- a/lib/libsqlite3/src/test8.c
+++ b/lib/libsqlite3/src/test8.c
@@ -1300,7 +1300,7 @@ static sqlite3_module echoModuleV2 = {
 ** Decode a pointer to an sqlite3 object.
 */
 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
-extern const char *sqlite3TestErrorName(int rc);
+extern const char *sqlite3ErrName(int);
 
 static void moduleDestroy(void *p){
   sqlite3_free(p);
@@ -1340,7 +1340,7 @@ static int register_echo_module(
     );
   }
 
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
   return TCL_OK;
 }
 
@@ -1370,29 +1370,6 @@ static int declare_vtab(
   return TCL_OK;
 }
 
-#include "test_spellfix.c"
-
-/*
-** Register the spellfix virtual table module.
-*/
-static int register_spellfix_module(
-  ClientData clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  sqlite3 *db;
-
-  if( objc!=2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "DB");
-    return TCL_ERROR;
-  }
-  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
-
-  sqlite3Spellfix1Register(db);
-  return TCL_OK;
-}
-
 #endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
 
 /*
@@ -1406,7 +1383,6 @@ int Sqlitetest8_Init(Tcl_Interp *interp){
      void *clientData;
   } aObjCmd[] = {
      { "register_echo_module",       register_echo_module, 0 },
-     { "register_spellfix_module",   register_spellfix_module, 0 },
      { "sqlite3_declare_vtab",       declare_vtab, 0 },
   };
   int i;
diff --git a/lib/libsqlite3/src/test_async.c b/lib/libsqlite3/src/test_async.c
index c760eea1fa2..b0b943185bf 100644
--- a/lib/libsqlite3/src/test_async.c
+++ b/lib/libsqlite3/src/test_async.c
@@ -23,8 +23,8 @@
 #include "sqlite3.h"
 #include <assert.h>
 
-/* From test1.c */
-const char *sqlite3TestErrorName(int);
+/* From main.c */
+extern const char *sqlite3ErrName(int);
 
 
 struct TestAsyncGlobal {
@@ -60,7 +60,7 @@ static int testAsyncInit(
 
   rc = sqlite3async_initialize(zParent, isDefault);
   if( rc!=SQLITE_OK ){
-    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3TestErrorName(rc), -1));
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
     return TCL_ERROR;
   }
   return TCL_OK;
@@ -208,7 +208,7 @@ static int testAsyncControl(
   }
 
   if( rc!=SQLITE_OK ){
-    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3TestErrorName(rc), -1));
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
     return TCL_ERROR;
   }
 
diff --git a/lib/libsqlite3/src/test_autoext.c b/lib/libsqlite3/src/test_autoext.c
index 6b1e297ab7c..b5013f3173a 100644
--- a/lib/libsqlite3/src/test_autoext.c
+++ b/lib/libsqlite3/src/test_autoext.c
@@ -15,7 +15,7 @@
 #include "sqlite3ext.h"
 
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
-static SQLITE_EXTENSION_INIT1
+SQLITE_EXTENSION_INIT1
 
 /*
 ** The sqr() SQL function returns the square of its input value.
diff --git a/lib/libsqlite3/src/test_backup.c b/lib/libsqlite3/src/test_backup.c
index 272713785a1..e967424a290 100644
--- a/lib/libsqlite3/src/test_backup.c
+++ b/lib/libsqlite3/src/test_backup.c
@@ -17,9 +17,11 @@
 #include <sqlite3.h>
 #include <assert.h>
 
+/* These functions are implemented in main.c. */
+extern const char *sqlite3ErrName(int);
+
 /* These functions are implemented in test1.c. */
-int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
-const char *sqlite3TestErrorName(int);
+extern int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
 
 static int backupTestCmd(
   ClientData clientData, 
@@ -70,7 +72,7 @@ static int backupTestCmd(
       Tcl_DeleteCommand(interp, zCmdName);
 
       rc = sqlite3_backup_finish(p);
-      Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+      Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
       break;
     }
 
@@ -80,7 +82,7 @@ static int backupTestCmd(
         return TCL_ERROR;
       }
       rc = sqlite3_backup_step(p, nPage);
-      Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+      Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
       break;
     }
 
diff --git a/lib/libsqlite3/src/test_config.c b/lib/libsqlite3/src/test_config.c
index f79b455a57f..534727a0804 100644
--- a/lib/libsqlite3/src/test_config.c
+++ b/lib/libsqlite3/src/test_config.c
@@ -57,7 +57,7 @@ static void set_options(Tcl_Interp *interp){
   Tcl_SetVar2(interp, "sqlite_options","casesensitivelike","0",TCL_GLOBAL_ONLY);
 #endif
 
-#ifdef SQLITE_CURDIR
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
   Tcl_SetVar2(interp, "sqlite_options", "curdir", "1", TCL_GLOBAL_ONLY);
 #else
   Tcl_SetVar2(interp, "sqlite_options", "curdir", "0", TCL_GLOBAL_ONLY);
@@ -87,6 +87,12 @@ static void set_options(Tcl_Interp *interp){
   Tcl_SetVar2(interp, "sqlite_options", "lfs", "1", TCL_GLOBAL_ONLY);
 #endif
 
+#if SQLITE_MAX_MMAP_SIZE>0
+  Tcl_SetVar2(interp, "sqlite_options", "mmap", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "mmap", "0", TCL_GLOBAL_ONLY);
+#endif
+
 #if 1 /* def SQLITE_MEMDEBUG */
   Tcl_SetVar2(interp, "sqlite_options", "memdebug", "1", TCL_GLOBAL_ONLY);
 #else
@@ -395,11 +401,7 @@ Tcl_SetVar2(interp, "sqlite_options", "long_double",
   Tcl_SetVar2(interp, "sqlite_options", "memorymanage", "0", TCL_GLOBAL_ONLY);
 #endif
 
-#ifdef SQLITE_OMIT_MERGE_SORT
-  Tcl_SetVar2(interp, "sqlite_options", "mergesort", "0", TCL_GLOBAL_ONLY);
-#else
-  Tcl_SetVar2(interp, "sqlite_options", "mergesort", "1", TCL_GLOBAL_ONLY);
-#endif
+Tcl_SetVar2(interp, "sqlite_options", "mergesort", "1", TCL_GLOBAL_ONLY);
 
 #ifdef SQLITE_OMIT_OR_OPTIMIZATION
   Tcl_SetVar2(interp, "sqlite_options", "or_opt", "0", TCL_GLOBAL_ONLY);
diff --git a/lib/libsqlite3/src/test_fs.c b/lib/libsqlite3/src/test_fs.c
new file mode 100644
index 00000000000..478cad80b16
--- /dev/null
+++ b/lib/libsqlite3/src/test_fs.c
@@ -0,0 +1,333 @@
+/*
+** 2013 Jan 11
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the virtual table interfaces.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+**
+** The FS virtual table is created as follows:
+**
+**   CREATE VIRTUAL TABLE tbl USING fs(idx);
+**
+** where idx is the name of a table in the db with 2 columns.  The virtual
+** table also has two columns - file path and file contents.
+**
+** The first column of table idx must be an IPK, and the second contains file
+** paths. For example:
+**
+**   CREATE TABLE idx(id INTEGER PRIMARY KEY, path TEXT);
+**   INSERT INTO idx VALUES(4, '/etc/passwd');
+**
+** Adding the row to the idx table automatically creates a row in the 
+** virtual table with rowid=4, path=/etc/passwd and a text field that 
+** contains data read from file /etc/passwd on disk.
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#if SQLITE_OS_UNIX
+# include <unistd.h>
+#endif
+#if SQLITE_OS_WIN
+# include <io.h>
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+typedef struct fs_vtab fs_vtab;
+typedef struct fs_cursor fs_cursor;
+
+/* 
+** A fs virtual-table object 
+*/
+struct fs_vtab {
+  sqlite3_vtab base;
+  sqlite3 *db;
+  char *zDb;                      /* Name of db containing zTbl */
+  char *zTbl;                     /* Name of docid->file map table */
+};
+
+/* A fs cursor object */
+struct fs_cursor {
+  sqlite3_vtab_cursor base;
+  sqlite3_stmt *pStmt;
+  char *zBuf;
+  int nBuf;
+  int nAlloc;
+};
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the fs virtual table.
+**
+** The argv[] array contains the following:
+**
+**   argv[0]   -> module name  ("fs")
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**   argv[...] -> other module argument fields.
+*/
+static int fsConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  fs_vtab *pVtab;
+  int nByte;
+  const char *zTbl;
+  const char *zDb = argv[1];
+
+  if( argc!=4 ){
+    *pzErr = sqlite3_mprintf("wrong number of arguments");
+    return SQLITE_ERROR;
+  }
+  zTbl = argv[3];
+
+  nByte = sizeof(fs_vtab) + (int)strlen(zTbl) + 1 + (int)strlen(zDb) + 1;
+  pVtab = (fs_vtab *)sqlite3MallocZero( nByte );
+  if( !pVtab ) return SQLITE_NOMEM;
+
+  pVtab->zTbl = (char *)&pVtab[1];
+  pVtab->zDb = &pVtab->zTbl[strlen(zTbl)+1];
+  pVtab->db = db;
+  memcpy(pVtab->zTbl, zTbl, strlen(zTbl));
+  memcpy(pVtab->zDb, zDb, strlen(zDb));
+  *ppVtab = &pVtab->base;
+  sqlite3_declare_vtab(db, "CREATE TABLE xyz(path TEXT, data TEXT)");
+
+  return SQLITE_OK;
+}
+/* Note that for this virtual table, the xCreate and xConnect
+** methods are identical. */
+
+static int fsDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+/* The xDisconnect and xDestroy methods are also the same */
+
+/*
+** Open a new fs cursor.
+*/
+static int fsOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  fs_cursor *pCur;
+  pCur = sqlite3MallocZero(sizeof(fs_cursor));
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+/*
+** Close a fs cursor.
+*/
+static int fsClose(sqlite3_vtab_cursor *cur){
+  fs_cursor *pCur = (fs_cursor *)cur;
+  sqlite3_finalize(pCur->pStmt);
+  sqlite3_free(pCur->zBuf);
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+static int fsNext(sqlite3_vtab_cursor *cur){
+  fs_cursor *pCur = (fs_cursor *)cur;
+  int rc;
+
+  rc = sqlite3_step(pCur->pStmt);
+  if( rc==SQLITE_ROW || rc==SQLITE_DONE ) rc = SQLITE_OK;
+
+  return rc;
+}
+
+static int fsFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  int rc;
+  fs_cursor *pCur = (fs_cursor *)pVtabCursor;
+  fs_vtab *p = (fs_vtab *)(pVtabCursor->pVtab);
+
+  assert( (idxNum==0 && argc==0) || (idxNum==1 && argc==1) );
+  if( idxNum==1 ){
+    char *zStmt = sqlite3_mprintf(
+        "SELECT * FROM %Q.%Q WHERE rowid=?", p->zDb, p->zTbl);
+    if( !zStmt ) return SQLITE_NOMEM;
+    rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0);
+    sqlite3_free(zStmt);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_value(pCur->pStmt, 1, argv[0]);
+    }
+  }else{
+    char *zStmt = sqlite3_mprintf("SELECT * FROM %Q.%Q", p->zDb, p->zTbl);
+    if( !zStmt ) return SQLITE_NOMEM;
+    rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0);
+    sqlite3_free(zStmt);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = fsNext(pVtabCursor); 
+  }
+  return rc;
+}
+
+static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  fs_cursor *pCur = (fs_cursor*)cur;
+
+  assert( i==0 || i==1 );
+  if( i==0 ){
+    sqlite3_result_value(ctx, sqlite3_column_value(pCur->pStmt, 0));
+  }else{
+    const char *zFile = (const char *)sqlite3_column_text(pCur->pStmt, 1);
+    struct stat sbuf;
+    int fd;
+
+    fd = open(zFile, O_RDONLY);
+    if( fd<0 ) return SQLITE_IOERR;
+    fstat(fd, &sbuf);
+
+    if( sbuf.st_size>=pCur->nAlloc ){
+      int nNew = sbuf.st_size*2;
+      char *zNew;
+      if( nNew<1024 ) nNew = 1024;
+
+      zNew = sqlite3Realloc(pCur->zBuf, nNew);
+      if( zNew==0 ){
+        close(fd);
+        return SQLITE_NOMEM;
+      }
+      pCur->zBuf = zNew;
+      pCur->nAlloc = nNew;
+    }
+
+    read(fd, pCur->zBuf, sbuf.st_size);
+    close(fd);
+    pCur->nBuf = sbuf.st_size;
+    pCur->zBuf[pCur->nBuf] = '\0';
+
+    sqlite3_result_text(ctx, pCur->zBuf, -1, SQLITE_TRANSIENT);
+  }
+  return SQLITE_OK;
+}
+
+static int fsRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  fs_cursor *pCur = (fs_cursor*)cur;
+  *pRowid = sqlite3_column_int64(pCur->pStmt, 0);
+  return SQLITE_OK;
+}
+
+static int fsEof(sqlite3_vtab_cursor *cur){
+  fs_cursor *pCur = (fs_cursor*)cur;
+  return (sqlite3_data_count(pCur->pStmt)==0);
+}
+
+static int fsBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int ii;
+
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];
+    if( pCons->iColumn<0 && pCons->usable
+           && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+      struct sqlite3_index_constraint_usage *pUsage;
+      pUsage = &pIdxInfo->aConstraintUsage[ii];
+      pUsage->omit = 0;
+      pUsage->argvIndex = 1;
+      pIdxInfo->idxNum = 1;
+      pIdxInfo->estimatedCost = 1.0;
+      break;
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that provides read-only access to a
+** Tcl global variable namespace.
+*/
+static sqlite3_module fsModule = {
+  0,                         /* iVersion */
+  fsConnect,
+  fsConnect,
+  fsBestIndex,
+  fsDisconnect, 
+  fsDisconnect,
+  fsOpen,                      /* xOpen - open a cursor */
+  fsClose,                     /* xClose - close a cursor */
+  fsFilter,                    /* xFilter - configure scan constraints */
+  fsNext,                      /* xNext - advance a cursor */
+  fsEof,                       /* xEof - check for end of scan */
+  fsColumn,                    /* xColumn - read data */
+  fsRowid,                     /* xRowid - read data */
+  0,                           /* xUpdate */
+  0,                           /* xBegin */
+  0,                           /* xSync */
+  0,                           /* xCommit */
+  0,                           /* xRollback */
+  0,                           /* xFindMethod */
+  0,                           /* xRename */
+};
+
+/*
+** Decode a pointer to an sqlite3 object.
+*/
+extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
+
+/*
+** Register the echo virtual table module.
+*/
+static int register_fs_module(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_create_module(db, "fs", &fsModule, (void *)interp);
+#endif
+  return TCL_OK;
+}
+
+#endif
+
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetestfs_Init(Tcl_Interp *interp){
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+     { "register_fs_module",   register_fs_module, 0 },
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+#endif
+  return TCL_OK;
+}
diff --git a/lib/libsqlite3/src/test_intarray.c b/lib/libsqlite3/src/test_intarray.c
index 6ea77561768..f5c3d9e4059 100644
--- a/lib/libsqlite3/src/test_intarray.c
+++ b/lib/libsqlite3/src/test_intarray.c
@@ -278,7 +278,7 @@ int sqlite3_intarray_bind(
 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
 extern void *sqlite3TestTextToPtr(const char*);
 extern int sqlite3TestMakePointerStr(Tcl_Interp*, char *zPtr, void*);
-extern const char *sqlite3TestErrorName(int);
+extern const char *sqlite3ErrName(int);
 
 /*
 **    sqlite3_intarray_create  DB  NAME
@@ -309,7 +309,7 @@ static int test_intarray_create(
 #endif
   if( rc!=SQLITE_OK ){
     assert( pArray==0 );
-    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), (char*)0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), (char*)0);
     return TCL_ERROR;
   }
   sqlite3TestMakePointerStr(interp, zPtr, pArray);
@@ -352,7 +352,7 @@ static int test_intarray_bind(
   }
   rc = sqlite3_intarray_bind(pArray, n, a, sqlite3_free);
   if( rc!=SQLITE_OK ){
-    Tcl_AppendResult(interp, sqlite3TestErrorName(rc), (char*)0);
+    Tcl_AppendResult(interp, sqlite3ErrName(rc), (char*)0);
     return TCL_ERROR;
   }
 #endif
diff --git a/lib/libsqlite3/src/test_malloc.c b/lib/libsqlite3/src/test_malloc.c
index 33de859d274..cf98a8fb218 100644
--- a/lib/libsqlite3/src/test_malloc.c
+++ b/lib/libsqlite3/src/test_malloc.c
@@ -234,14 +234,14 @@ static int faultsimInstall(int install){
 #ifdef SQLITE_TEST
 
 /*
-** This function is implemented in test1.c. Returns a pointer to a static
+** This function is implemented in main.c. Returns a pointer to a static
 ** buffer containing the symbolic SQLite error code that corresponds to
 ** the least-significant 8-bits of the integer passed as an argument.
 ** For example:
 **
-**   sqlite3TestErrorName(1) -> "SQLITE_ERROR"
+**   sqlite3ErrName(1) -> "SQLITE_ERROR"
 */
-const char *sqlite3TestErrorName(int);
+extern const char *sqlite3ErrName(int);
 
 /*
 ** Transform pointers to text and back again
@@ -1072,7 +1072,7 @@ static int test_db_config_lookaside(
   sqlite3 *db;
   int bufid;
   static char azBuf[2][10000];
-  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+  extern int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
   if( objc!=5 ){
     Tcl_WrongNumArgs(interp, 1, objv, "BUFID SIZE COUNT");
     return TCL_ERROR;
@@ -1126,7 +1126,7 @@ static int test_config_heap(
     rc = sqlite3_config(SQLITE_CONFIG_HEAP, zBuf, nByte, nMinAlloc);
   }
 
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
@@ -1143,7 +1143,7 @@ static int test_config_error(
   Tcl_Obj *CONST objv[]
 ){
   sqlite3 *db;
-  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+  extern int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
 
   if( objc!=2 && objc!=1 ){
     Tcl_WrongNumArgs(interp, 1, objv, "[DB]");
@@ -1192,7 +1192,7 @@ static int test_config_uri(
   }
 
   rc = sqlite3_config(SQLITE_CONFIG_URI, bOpenUri);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
 
   return TCL_OK;
 }
@@ -1221,7 +1221,7 @@ static int test_config_cis(
   }
 
   rc = sqlite3_config(SQLITE_CONFIG_COVERING_INDEX_SCAN, bUseCis);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
 
   return TCL_OK;
 }
@@ -1335,7 +1335,7 @@ static int test_db_status(
   int i, op, resetFlag;
   const char *zOpName;
   sqlite3 *db;
-  int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
+  extern int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
   static const struct {
     const char *zName;
     int op;
@@ -1401,7 +1401,7 @@ static int test_install_malloc_faultsim(
     return TCL_ERROR;
   }
   rc = faultsimInstall(isInstall);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
@@ -1419,7 +1419,7 @@ static int test_install_memsys3(
   const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
   rc = sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetMemsys3());
 #endif
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
diff --git a/lib/libsqlite3/src/test_multiplex.c b/lib/libsqlite3/src/test_multiplex.c
index 23df347ded5..624541b32a1 100644
--- a/lib/libsqlite3/src/test_multiplex.c
+++ b/lib/libsqlite3/src/test_multiplex.c
@@ -60,7 +60,7 @@
 
 /* 
 ** These should be defined to be the same as the values in 
-** sqliteInt.h.  They are defined seperately here so that
+** sqliteInt.h.  They are defined separately here so that
 ** the multiplex VFS shim can be built as a loadable 
 ** module.
 */
@@ -1183,7 +1183,7 @@ int sqlite3_multiplex_shutdown(void){
 /***************************** Test Code ***********************************/
 #ifdef SQLITE_TEST
 #include <tcl.h>
-extern const char *sqlite3TestErrorName(int);
+extern const char *sqlite3ErrName(int);
 
 
 /*
@@ -1212,7 +1212,7 @@ static int test_multiplex_initialize(
 
   /* Call sqlite3_multiplex_initialize() */
   rc = sqlite3_multiplex_initialize(zName, makeDefault);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 
   return TCL_OK;
 }
@@ -1237,7 +1237,7 @@ static int test_multiplex_shutdown(
 
   /* Call sqlite3_multiplex_shutdown() */
   rc = sqlite3_multiplex_shutdown();
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 
   return TCL_OK;
 }
@@ -1355,7 +1355,7 @@ static int test_multiplex_control(
   }
 
   rc = sqlite3_file_control(db, Tcl_GetString(objv[2]), aSub[idx].op, pArg);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
   return (rc==SQLITE_OK) ? TCL_OK : TCL_ERROR;
 }
 
diff --git a/lib/libsqlite3/src/test_mutex.c b/lib/libsqlite3/src/test_mutex.c
index 0bb74375d8f..c9b4a29ab75 100644
--- a/lib/libsqlite3/src/test_mutex.c
+++ b/lib/libsqlite3/src/test_mutex.c
@@ -19,8 +19,8 @@
 #include <assert.h>
 #include <string.h>
 
-/* defined in test1.c */
-const char *sqlite3TestErrorName(int);
+/* defined in main.c */
+extern const char *sqlite3ErrName(int);
 
 /* A countable mutex */
 struct sqlite3_mutex {
@@ -148,7 +148,7 @@ static int test_shutdown(
   }
 
   rc = sqlite3_shutdown();
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
@@ -169,7 +169,7 @@ static int test_initialize(
   }
 
   rc = sqlite3_initialize();
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
@@ -230,7 +230,7 @@ static int test_install_mutex_counters(
     g.isInstalled = isInstall;
   }
 
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
@@ -354,7 +354,7 @@ static int test_config(
   }
 
   rc = sqlite3_config(i);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
   return TCL_OK;
 }
 
diff --git a/lib/libsqlite3/src/test_quota.c b/lib/libsqlite3/src/test_quota.c
index 166a512f18c..e590996ca4b 100644
--- a/lib/libsqlite3/src/test_quota.c
+++ b/lib/libsqlite3/src/test_quota.c
@@ -1295,7 +1295,7 @@ int sqlite3_quota_remove(const char *zFilename){
   if( pGroup ){
     for(pFile=pGroup->pFiles; pFile && rc==SQLITE_OK; pFile=pNextFile){
       pNextFile = pFile->pNext;
-      diff = memcmp(zFull, pFile->zFilename, nFull);
+      diff = strncmp(zFull, pFile->zFilename, nFull);
       if( diff==0 && ((c = pFile->zFilename[nFull])==0 || c=='/' || c=='\\') ){
         if( pFile->nRef ){
           pFile->deleteOnClose = 1;
@@ -1325,7 +1325,7 @@ struct TclQuotaCallback {
   Tcl_Obj *pScript;      /* Script to be run */
 };
 
-extern const char *sqlite3TestErrorName(int);
+extern const char *sqlite3ErrName(int);
 
 
 /*
@@ -1407,7 +1407,7 @@ static int test_quota_initialize(
 
   /* Call sqlite3_quota_initialize() */
   rc = sqlite3_quota_initialize(zName, makeDefault);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 
   return TCL_OK;
 }
@@ -1430,7 +1430,7 @@ static int test_quota_shutdown(
 
   /* Call sqlite3_quota_shutdown() */
   rc = sqlite3_quota_shutdown();
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 
   return TCL_OK;
 }
@@ -1485,7 +1485,7 @@ static int test_quota_set(
   /* Invoke sqlite3_quota_set() */
   rc = sqlite3_quota_set(zPattern, iLimit, xCallback, (void*)p, xDestroy);
 
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
   return TCL_OK;
 }
 
@@ -1511,7 +1511,7 @@ static int test_quota_file(
   /* Invoke sqlite3_quota_file() */
   rc = sqlite3_quota_file(zFilename);
 
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
   return TCL_OK;
 }
 
diff --git a/lib/libsqlite3/src/test_rtree.c b/lib/libsqlite3/src/test_rtree.c
index d3c9e0cb3de..f54ae9b063b 100644
--- a/lib/libsqlite3/src/test_rtree.c
+++ b/lib/libsqlite3/src/test_rtree.c
@@ -254,7 +254,7 @@ static int register_cube_geom(
   UNUSED_PARAMETER(objv);
 #else
   extern int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
-  extern const char *sqlite3TestErrorName(int);
+  extern const char *sqlite3ErrName(int);
   sqlite3 *db;
   int rc;
 
@@ -264,7 +264,7 @@ static int register_cube_geom(
   }
   if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
   rc = sqlite3_rtree_geometry_callback(db, "cube", cube_geom, (void *)&gHere);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 #endif
   return TCL_OK;
 }
@@ -282,7 +282,7 @@ static int register_circle_geom(
   UNUSED_PARAMETER(objv);
 #else
   extern int getDbPointer(Tcl_Interp*, const char*, sqlite3**);
-  extern const char *sqlite3TestErrorName(int);
+  extern const char *sqlite3ErrName(int);
   sqlite3 *db;
   int rc;
 
@@ -292,7 +292,7 @@ static int register_circle_geom(
   }
   if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
   rc = sqlite3_rtree_geometry_callback(db, "circle", circle_geom, 0);
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_STATIC);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 #endif
   return TCL_OK;
 }
diff --git a/lib/libsqlite3/src/test_sqllog.c b/lib/libsqlite3/src/test_sqllog.c
index 7cb570bcf22..4aa68b7c429 100644
--- a/lib/libsqlite3/src/test_sqllog.c
+++ b/lib/libsqlite3/src/test_sqllog.c
@@ -13,26 +13,36 @@
 ** OVERVIEW
 **
 **   This file contains experimental code used to record data from live
-**   SQLite applications that may be useful for offline analysis. Specifically:
+**   SQLite applications that may be useful for offline analysis. 
+**   Specifically, this module can be used to capture the following
+**   information:
 **
 **     1) The initial contents of all database files opened by the 
 **        application, and
 **
 **     2) All SQL statements executed by the application.
 **
+**   The captured information can then be used to run (for example)
+**   performance analysis looking for slow queries or to look for
+**   optimization opportunities in either the application or in SQLite
+**   itself.
+**
 ** USAGE
 **
 **   To use this module, SQLite must be compiled with the SQLITE_ENABLE_SQLLOG
-**   pre-processor symbol defined and this file linked into the application
-**   somehow.
+**   pre-processor symbol defined and this file linked into the application.
+**   One way to link this file into the application is to append the content
+**   of this file onto the end of the "sqlite3.c" amalgamation and then 
+**   recompile the application as normal except with the addition  of the
+**   -DSQLITE_ENABLE_SQLLOG option.
 **
 **   At runtime, logging is enabled by setting environment variable
 **   SQLITE_SQLLOG_DIR to the name of a directory in which to store logged 
-**   data. The directory must already exist.
+**   data. The logging directory must already exist.
 **
 **   Usually, if the application opens the same database file more than once
 **   (either by attaching it or by using more than one database handle), only
-**   a single copy is made. This behaviour may be overridden (so that a 
+**   a single copy is made. This behavior may be overridden (so that a 
 **   separate copy is taken each time the database file is opened or attached)
 **   by setting the environment variable SQLITE_SQLLOG_REUSE_FILES to 0.
 **
@@ -57,14 +67,16 @@
 **   logging proceeds as expected. Errors are logged by calling sqlite3_log().
 */
 
+#ifndef _SQLITE3_H_
 #include "sqlite3.h"
-#include "stdio.h"
-#include "stdlib.h"
-#include "string.h"
-#include "assert.h"
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
 
-#include "sys/types.h"
-#include "unistd.h"
+#include <sys/types.h>
+#include <unistd.h>
 static int getProcessId(void){
 #if SQLITE_OS_WIN
   return (int)_getpid();
@@ -73,7 +85,7 @@ static int getProcessId(void){
 #endif
 }
 
-
+/* Names of environment variables to be used */
 #define ENVIRONMENT_VARIABLE1_NAME "SQLITE_SQLLOG_DIR"
 #define ENVIRONMENT_VARIABLE2_NAME "SQLITE_SQLLOG_REUSE_FILES"
 
@@ -86,6 +98,9 @@ static int getProcessId(void){
 */
 #define MAX_CONNECTIONS 256
 
+/* There is one instance of this object for each SQLite database connection
+** that is being logged.
+*/
 struct SLConn {
   int isErr;                      /* True if an error has occurred */
   sqlite3 *db;                    /* Connection handle */
@@ -93,7 +108,9 @@ struct SLConn {
   FILE *fd;                       /* File descriptor for log file */
 };
 
-struct SLGlobal {
+/* This object is a singleton that keeps track of all data loggers.
+*/
+static struct SLGlobal {
   /* Protected by MUTEX_STATIC_MASTER */
   sqlite3_mutex *mutex;           /* Recursive mutex */
   int nConn;                      /* Size of aConn[] array */
@@ -388,6 +405,24 @@ static void testSqllogStmt(struct SLConn *p, const char *zSql){
 
 /*
 ** The SQLITE_CONFIG_SQLLOG callback registered by sqlite3_init_sqllog().
+**
+** The eType parameter has the following values:
+**
+**    0:  Opening a new database connection.  zSql is the name of the
+**        file being opened.  db is a pointer to the newly created database
+**        connection.
+**
+**    1:  An SQL statement has run to completion.  zSql is the text of the
+**        SQL statement with all parameters expanded to their actual values.
+**
+**    2:  Closing a database connection.  zSql is NULL.  The db pointer to
+**        the database connection being closed has already been shut down
+**        and cannot be used for any further SQL.
+**
+** The pCtx parameter is a copy of the pointer that was originally passed
+** into the sqlite3_config(SQLITE_CONFIG_SQLLOG) statement.  In this
+** particular implementation, pCtx is always a pointer to the 
+** sqllogglobal global variable define above.
 */
 static void testSqllog(void *pCtx, sqlite3 *db, const char *zSql, int eType){
   struct SLConn *p = 0;
diff --git a/lib/libsqlite3/src/test_syscall.c b/lib/libsqlite3/src/test_syscall.c
index d484f22db4b..7c0873c16d8 100644
--- a/lib/libsqlite3/src/test_syscall.c
+++ b/lib/libsqlite3/src/test_syscall.c
@@ -23,7 +23,7 @@
 **
 **         open        close      access   getcwd   stat      fstat    
 **         ftruncate   fcntl      read     pread    pread64   write
-**         pwrite      pwrite64   fchmod   fallocate
+**         pwrite      pwrite64   fchmod   fallocate mmap
 **
 **   test_syscall uninstall
 **     Uninstall all wrapper functions.
@@ -69,18 +69,19 @@
 **     the xNextSystemCall() VFS method.
 */
 
+#include "sqliteInt.h"
 #include "sqlite3.h"
 #include "tcl.h"
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 
-#include "sqliteInt.h"
 #if SQLITE_OS_UNIX
 
-/* From test1.c */
-extern const char *sqlite3TestErrorName(int);
+/* From main.c */
+extern const char *sqlite3ErrName(int);
 
+#include <sys/mman.h>
 #include <sys/types.h>
 #include <errno.h>
 
@@ -106,7 +107,8 @@ static int ts_pwrite(int fd, const void *aBuf, size_t nBuf, off_t off);
 static int ts_pwrite64(int fd, const void *aBuf, size_t nBuf, off_t off);
 static int ts_fchmod(int fd, mode_t mode);
 static int ts_fallocate(int fd, off_t off, off_t len);
-
+static void *ts_mmap(void *, size_t, int, int, int, off_t);
+static void *ts_mremap(void*, size_t, size_t, int, ...);
 
 struct TestSyscallArray {
   const char *zName;
@@ -131,6 +133,8 @@ struct TestSyscallArray {
   /* 13 */ { "pwrite64",  (sqlite3_syscall_ptr)ts_pwrite64,  0, 0, 0 },
   /* 14 */ { "fchmod",    (sqlite3_syscall_ptr)ts_fchmod,    0, 0, 0 },
   /* 15 */ { "fallocate", (sqlite3_syscall_ptr)ts_fallocate, 0, 0, 0 },
+  /* 16 */ { "mmap",      (sqlite3_syscall_ptr)ts_mmap,      0, 0, 0 },
+  /* 17 */ { "mremap",    (sqlite3_syscall_ptr)ts_mremap,    0, 0, 0 },
            { 0, 0, 0, 0, 0 }
 };
 
@@ -152,6 +156,8 @@ struct TestSyscallArray {
                        aSyscall[13].xOrig)
 #define orig_fchmod    ((int(*)(int,mode_t))aSyscall[14].xOrig)
 #define orig_fallocate ((int(*)(int,off_t,off_t))aSyscall[15].xOrig)
+#define orig_mmap      ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[16].xOrig)
+#define orig_mremap    ((void*(*)(void*,size_t,size_t,int,...))aSyscall[17].xOrig)
 
 /*
 ** This function is called exactly once from within each invocation of a
@@ -377,6 +383,31 @@ static int ts_fallocate(int fd, off_t off, off_t len){
   return orig_fallocate(fd, off, len);
 }
 
+static void *ts_mmap(
+  void *pAddr, 
+  size_t nByte, 
+  int prot, 
+  int flags, 
+  int fd, 
+  off_t iOff
+){
+  if( tsIsFailErrno("mmap") ){
+    return MAP_FAILED;
+  }
+  return orig_mmap(pAddr, nByte, prot, flags, fd, iOff);
+}
+
+static void *ts_mremap(void *a, size_t b, size_t c, int d, ...){
+  va_list ap;
+  void *pArg;
+  if( tsIsFailErrno("mremap") ){
+    return MAP_FAILED;
+  }
+  va_start(ap, d);
+  pArg = va_arg(ap, void *);
+  return orig_mremap(a, b, c, d, pArg);
+}
+
 static int test_syscall_install(
   void * clientData,
   Tcl_Interp *interp,
@@ -467,7 +498,7 @@ static int test_syscall_reset(
     }
   }
   if( rc!=SQLITE_OK ){
-    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3TestErrorName(rc), -1));
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
     return TCL_ERROR;
   }
 
diff --git a/lib/libsqlite3/src/test_thread.c b/lib/libsqlite3/src/test_thread.c
index ae62de8262d..2f9363b7501 100644
--- a/lib/libsqlite3/src/test_thread.c
+++ b/lib/libsqlite3/src/test_thread.c
@@ -60,12 +60,14 @@ static Tcl_ObjCmdProc blocking_prepare_v2_proc;
 int Sqlitetest1_Init(Tcl_Interp *);
 int Sqlite3_Init(Tcl_Interp *);
 
+/* Functions from main.c */
+extern const char *sqlite3ErrName(int);
+
 /* Functions from test1.c */
-void *sqlite3TestTextToPtr(const char *);
-const char *sqlite3TestErrorName(int);
-int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
-int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *);
-int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int);
+extern void *sqlite3TestTextToPtr(const char *);
+extern int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
+extern int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *);
+extern int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int);
 
 /*
 ** Handler for events of type EvalEvent.
@@ -559,7 +561,7 @@ static int blocking_step_proc(
   pStmt = (sqlite3_stmt*)sqlite3TestTextToPtr(Tcl_GetString(objv[1]));
   rc = sqlite3_blocking_step(pStmt);
 
-  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), 0);
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), 0);
   return TCL_OK;
 }
 
@@ -606,7 +608,7 @@ static int blocking_prepare_v2_proc(
   }
   if( rc!=SQLITE_OK ){
     assert( pStmt==0 );
-    sprintf(zBuf, "%s ", (char *)sqlite3TestErrorName(rc));
+    sprintf(zBuf, "%s ", (char *)sqlite3ErrName(rc));
     Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0);
     return TCL_ERROR;
   }
diff --git a/lib/libsqlite3/src/test_vfs.c b/lib/libsqlite3/src/test_vfs.c
index 93c556b56e0..fcd577439cf 100644
--- a/lib/libsqlite3/src/test_vfs.c
+++ b/lib/libsqlite3/src/test_vfs.c
@@ -125,8 +125,9 @@ struct Testvfs {
 #define TESTVFS_ACCESS_MASK       0x00004000
 #define TESTVFS_FULLPATHNAME_MASK 0x00008000
 #define TESTVFS_READ_MASK         0x00010000
+#define TESTVFS_UNLOCK_MASK       0x00020000
 
-#define TESTVFS_ALL_MASK          0x0001FFFF
+#define TESTVFS_ALL_MASK          0x0003FFFF
 
 
 #define TESTVFS_MAX_PAGES 1024
@@ -265,7 +266,8 @@ static void tvfsExecTcl(
   const char *zMethod,
   Tcl_Obj *arg1,
   Tcl_Obj *arg2,
-  Tcl_Obj *arg3
+  Tcl_Obj *arg3,
+  Tcl_Obj *arg4
 ){
   int rc;                         /* Return code from Tcl_EvalObj() */
   Tcl_Obj *pEval;
@@ -282,6 +284,7 @@ static void tvfsExecTcl(
   if( arg1 ) Tcl_ListObjAppendElement(p->interp, pEval, arg1);
   if( arg2 ) Tcl_ListObjAppendElement(p->interp, pEval, arg2);
   if( arg3 ) Tcl_ListObjAppendElement(p->interp, pEval, arg3);
+  if( arg4 ) Tcl_ListObjAppendElement(p->interp, pEval, arg4);
 
   rc = Tcl_EvalObjEx(p->interp, pEval, TCL_EVAL_GLOBAL);
   if( rc!=TCL_OK ){
@@ -302,7 +305,7 @@ static int tvfsClose(sqlite3_file *pFile){
 
   if( p->pScript && p->mask&TESTVFS_CLOSE_MASK ){
     tvfsExecTcl(p, "xClose", 
-        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0, 0
     );
   }
 
@@ -333,7 +336,7 @@ static int tvfsRead(
   Testvfs *p = (Testvfs *)pFd->pVfs->pAppData;
   if( p->pScript && p->mask&TESTVFS_READ_MASK ){
     tvfsExecTcl(p, "xRead", 
-        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -362,7 +365,7 @@ static int tvfsWrite(
   if( p->pScript && p->mask&TESTVFS_WRITE_MASK ){
     tvfsExecTcl(p, "xWrite", 
         Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 
-        Tcl_NewWideIntObj(iOfst)
+        Tcl_NewWideIntObj(iOfst), Tcl_NewIntObj(iAmt)
     );
     tvfsResultCode(p, &rc);
   }
@@ -390,7 +393,7 @@ static int tvfsTruncate(sqlite3_file *pFile, sqlite_int64 size){
 
   if( p->pScript && p->mask&TESTVFS_TRUNCATE_MASK ){
     tvfsExecTcl(p, "xTruncate", 
-        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -431,7 +434,7 @@ static int tvfsSync(sqlite3_file *pFile, int flags){
 
     tvfsExecTcl(p, "xSync", 
         Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId,
-        Tcl_NewStringObj(zFlags, -1)
+        Tcl_NewStringObj(zFlags, -1), 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -465,8 +468,12 @@ static int tvfsLock(sqlite3_file *pFile, int eLock){
 ** Unlock an tvfs-file.
 */
 static int tvfsUnlock(sqlite3_file *pFile, int eLock){
-  TestvfsFd *p = tvfsGetFd(pFile);
-  return sqlite3OsUnlock(p->pReal, eLock);
+  TestvfsFd *pFd = tvfsGetFd(pFile);
+  Testvfs *p = (Testvfs *)pFd->pVfs->pAppData;
+  if( p->mask&TESTVFS_WRITE_MASK && tvfsInjectIoerr(p) ){
+    return SQLITE_IOERR_UNLOCK;
+  }
+  return sqlite3OsUnlock(pFd->pReal, eLock);
 }
 
 /*
@@ -578,7 +585,7 @@ static int tvfsOpen(
         z += strlen(z) + 1;
       }
     }
-    tvfsExecTcl(p, "xOpen", Tcl_NewStringObj(pFd->zFilename, -1), pArg, 0);
+    tvfsExecTcl(p, "xOpen", Tcl_NewStringObj(pFd->zFilename, -1), pArg, 0, 0);
     Tcl_DecrRefCount(pArg);
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
@@ -635,7 +642,7 @@ static int tvfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
 
   if( p->pScript && p->mask&TESTVFS_DELETE_MASK ){
     tvfsExecTcl(p, "xDelete", 
-        Tcl_NewStringObj(zPath, -1), Tcl_NewIntObj(dirSync), 0
+        Tcl_NewStringObj(zPath, -1), Tcl_NewIntObj(dirSync), 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -663,7 +670,7 @@ static int tvfsAccess(
     if( flags==SQLITE_ACCESS_READWRITE ) zArg = "SQLITE_ACCESS_READWRITE";
     if( flags==SQLITE_ACCESS_READ ) zArg = "SQLITE_ACCESS_READ";
     tvfsExecTcl(p, "xAccess", 
-        Tcl_NewStringObj(zPath, -1), Tcl_NewStringObj(zArg, -1), 0
+        Tcl_NewStringObj(zPath, -1), Tcl_NewStringObj(zArg, -1), 0, 0
     );
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
@@ -691,7 +698,7 @@ static int tvfsFullPathname(
   Testvfs *p = (Testvfs *)pVfs->pAppData;
   if( p->pScript && p->mask&TESTVFS_FULLPATHNAME_MASK ){
     int rc;
-    tvfsExecTcl(p, "xFullPathname", Tcl_NewStringObj(zPath, -1), 0, 0);
+    tvfsExecTcl(p, "xFullPathname", Tcl_NewStringObj(zPath, -1), 0, 0, 0);
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
     }
@@ -771,7 +778,7 @@ static int tvfsShmOpen(sqlite3_file *pFile){
   */
   Tcl_ResetResult(p->interp);
   if( p->pScript && p->mask&TESTVFS_SHMOPEN_MASK ){
-    tvfsExecTcl(p, "xShmOpen", Tcl_NewStringObj(pFd->zFilename, -1), 0, 0);
+    tvfsExecTcl(p, "xShmOpen", Tcl_NewStringObj(pFd->zFilename, -1), 0, 0, 0);
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
     }
@@ -841,7 +848,7 @@ static int tvfsShmMap(
     Tcl_ListObjAppendElement(p->interp, pArg, Tcl_NewIntObj(pgsz));
     Tcl_ListObjAppendElement(p->interp, pArg, Tcl_NewIntObj(isWrite));
     tvfsExecTcl(p, "xShmMap", 
-        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, pArg
+        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, pArg, 0
     );
     tvfsResultCode(p, &rc);
     Tcl_DecrRefCount(pArg);
@@ -891,7 +898,7 @@ static int tvfsShmLock(
     }
     tvfsExecTcl(p, "xShmLock", 
         Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId,
-        Tcl_NewStringObj(zLock, -1)
+        Tcl_NewStringObj(zLock, -1), 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -937,7 +944,7 @@ static void tvfsShmBarrier(sqlite3_file *pFile){
 
   if( p->pScript && p->mask&TESTVFS_SHMBARRIER_MASK ){
     tvfsExecTcl(p, "xShmBarrier", 
-        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0, 0
     );
   }
 }
@@ -961,7 +968,7 @@ static int tvfsShmUnmap(
 
   if( p->pScript && p->mask&TESTVFS_SHMCLOSE_MASK ){
     tvfsExecTcl(p, "xShmUnmap", 
-        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -1099,6 +1106,7 @@ static int testvfs_obj_cmd(
         { "xClose",        TESTVFS_CLOSE_MASK },
         { "xAccess",       TESTVFS_ACCESS_MASK },
         { "xFullPathname", TESTVFS_FULLPATHNAME_MASK },
+        { "xUnlock",       TESTVFS_UNLOCK_MASK },
       };
       Tcl_Obj **apElem = 0;
       int nElem = 0;
diff --git a/lib/libsqlite3/src/update.c b/lib/libsqlite3/src/update.c
index 96ba4df83dd..3ab1ab2a4b6 100644
--- a/lib/libsqlite3/src/update.c
+++ b/lib/libsqlite3/src/update.c
@@ -208,6 +208,7 @@ void sqlite3Update(
     }
     if( j>=pTab->nCol ){
       if( sqlite3IsRowid(pChanges->a[i].zName) ){
+        j = -1;
         chngRowid = 1;
         pRowidExpr = pChanges->a[i].pExpr;
       }else{
@@ -220,7 +221,8 @@ void sqlite3Update(
     {
       int rc;
       rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
-                           pTab->aCol[j].zName, db->aDb[iDb].zName);
+                            j<0 ? "ROWID" : pTab->aCol[j].zName,
+                            db->aDb[iDb].zName);
       if( rc==SQLITE_DENY ){
         goto update_cleanup;
       }else if( rc==SQLITE_IGNORE ){
@@ -458,7 +460,7 @@ void sqlite3Update(
 
     /* The row-trigger may have deleted the row being updated. In this
     ** case, jump to the next row. No updates or AFTER triggers are 
-    ** required. This behaviour - what happens when the row being updated
+    ** required. This behavior - what happens when the row being updated
     ** is deleted or renamed by a BEFORE trigger - is left undefined in the
     ** documentation.
     */
diff --git a/lib/libsqlite3/src/util.c b/lib/libsqlite3/src/util.c
index 5cf8ebacb5d..d83a63015fd 100644
--- a/lib/libsqlite3/src/util.c
+++ b/lib/libsqlite3/src/util.c
@@ -261,7 +261,7 @@ int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
 */
 int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
 #ifndef SQLITE_OMIT_FLOATING_POINT
-  int incr = (enc==SQLITE_UTF8?1:2);
+  int incr;
   const char *zEnd = z + length;
   /* sign * significand * (10 ^ (esign * exponent)) */
   int sign = 1;    /* sign of significand */
@@ -272,10 +272,22 @@ int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
   int eValid = 1;  /* True exponent is either not used or is well-formed */
   double result;
   int nDigits = 0;
+  int nonNum = 0;
 
+  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
   *pResult = 0.0;   /* Default return value, in case of an error */
 
-  if( enc==SQLITE_UTF16BE ) z++;
+  if( enc==SQLITE_UTF8 ){
+    incr = 1;
+  }else{
+    int i;
+    incr = 2;
+    assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
+    for(i=3-enc; i<length && z[i]==0; i+=2){}
+    nonNum = i<length;
+    zEnd = z+i+enc-3;
+    z += (enc&1);
+  }
 
   /* skip leading spaces */
   while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
@@ -408,7 +420,7 @@ do_atof_calc:
   *pResult = result;
 
   /* return true if number and no extra non-whitespace chracters after */
-  return z>=zEnd && nDigits>0 && eValid;
+  return z>=zEnd && nDigits>0 && eValid && nonNum==0;
 #else
   return !sqlite3Atoi64(z, pResult, length, enc);
 #endif /* SQLITE_OMIT_FLOATING_POINT */
@@ -457,21 +469,33 @@ static int compare2pow63(const char *zNum, int incr){
 ** signed 64-bit integer, its negative -9223372036854665808 can be.
 **
 ** If zNum is too big for a 64-bit integer and is not
-** 9223372036854665808 then return 1.
+** 9223372036854665808  or if zNum contains any non-numeric text,
+** then return 1.
 **
 ** length is the number of bytes in the string (bytes, not characters).
 ** The string is not necessarily zero-terminated.  The encoding is
 ** given by enc.
 */
 int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){
-  int incr = (enc==SQLITE_UTF8?1:2);
+  int incr;
   u64 u = 0;
   int neg = 0; /* assume positive */
   int i;
   int c = 0;
+  int nonNum = 0;
   const char *zStart;
   const char *zEnd = zNum + length;
-  if( enc==SQLITE_UTF16BE ) zNum++;
+  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
+  if( enc==SQLITE_UTF8 ){
+    incr = 1;
+  }else{
+    incr = 2;
+    assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
+    for(i=3-enc; i<length && zNum[i]==0; i+=2){}
+    nonNum = i<length;
+    zEnd = zNum+i+enc-3;
+    zNum += (enc&1);
+  }
   while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr;
   if( zNum<zEnd ){
     if( *zNum=='-' ){
@@ -496,7 +520,7 @@ int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){
   testcase( i==18 );
   testcase( i==19 );
   testcase( i==20 );
-  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19*incr ){
+  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19*incr || nonNum ){
     /* zNum is empty or contains non-numeric text or is longer
     ** than 19 digits (thus guaranteeing that it is too large) */
     return 1;
diff --git a/lib/libsqlite3/src/vacuum.c b/lib/libsqlite3/src/vacuum.c
index 7ed2478326c..4afb2cca64d 100644
--- a/lib/libsqlite3/src/vacuum.c
+++ b/lib/libsqlite3/src/vacuum.c
@@ -289,6 +289,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
        BTREE_DEFAULT_CACHE_SIZE, 0,  /* Preserve the default page cache size */
        BTREE_TEXT_ENCODING,      0,  /* Preserve the text encoding */
        BTREE_USER_VERSION,       0,  /* Preserve the user version */
+       BTREE_APPLICATION_ID,     0,  /* Preserve the application id */
     };
 
     assert( 1==sqlite3BtreeIsInTrans(pTemp) );
diff --git a/lib/libsqlite3/src/vdbe.c b/lib/libsqlite3/src/vdbe.c
index a2ab31e879a..f343e13d4e9 100644
--- a/lib/libsqlite3/src/vdbe.c
+++ b/lib/libsqlite3/src/vdbe.c
@@ -152,11 +152,7 @@ int sqlite3_found_count = 0;
        && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
 
 /* Return true if the cursor was opened using the OP_OpenSorter opcode. */
-#ifdef SQLITE_OMIT_MERGE_SORT
-# define isSorter(x) 0
-#else
 # define isSorter(x) ((x)->pSorter!=0)
-#endif
 
 /*
 ** Argument pMem points at a register that will be passed to a
@@ -869,7 +865,7 @@ case OP_Halt: {
   if( rc==SQLITE_BUSY ){
     p->rc = rc = SQLITE_BUSY;
   }else{
-    assert( rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT );
+    assert( rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT );
     assert( rc==SQLITE_OK || db->nDeferredCons>0 );
     rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
   }
@@ -3321,17 +3317,12 @@ case OP_OpenEphemeral: {
 case OP_SorterOpen: {
   VdbeCursor *pCx;
 
-#ifndef SQLITE_OMIT_MERGE_SORT
   pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
   if( pCx==0 ) goto no_mem;
   pCx->pKeyInfo = pOp->p4.pKeyInfo;
   pCx->pKeyInfo->enc = ENC(p->db);
   pCx->isSorter = 1;
   rc = sqlite3VdbeSorterInit(db, pCx);
-#else
-  pOp->opcode = OP_OpenEphemeral;
-  pc--;
-#endif
   break;
 }
 
@@ -3524,7 +3515,7 @@ case OP_SeekGt: {       /* jump, in3 */
       **     r.flags = 0;
       **   }
       */
-      r.flags = (u16)(UNPACKED_INCRKEY * (1 & (oc - OP_SeekLt)));
+      r.flags = (u8)(UNPACKED_INCRKEY * (1 & (oc - OP_SeekLt)));
       assert( oc!=OP_SeekGt || r.flags==UNPACKED_INCRKEY );
       assert( oc!=OP_SeekLe || r.flags==UNPACKED_INCRKEY );
       assert( oc!=OP_SeekGe || r.flags==0 );
@@ -4214,15 +4205,10 @@ case OP_SorterCompare: {
 case OP_SorterData: {
   VdbeCursor *pC;
 
-#ifndef SQLITE_OMIT_MERGE_SORT
   pOut = &aMem[pOp->p2];
   pC = p->apCsr[pOp->p1];
   assert( pC->isSorter );
   rc = sqlite3VdbeSorterRowkey(pC, pOut);
-#else
-  pOp->opcode = OP_RowKey;
-  pc--;
-#endif
   break;
 }
 
@@ -4421,9 +4407,6 @@ case OP_Last: {        /* jump */
 ** correctly optimizing out sorts.
 */
 case OP_SorterSort:    /* jump */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  pOp->opcode = OP_Sort;
-#endif
 case OP_Sort: {        /* jump */
 #ifdef SQLITE_TEST
   sqlite3_sort_count++;
@@ -4502,9 +4485,6 @@ case OP_Rewind: {        /* jump */
 ** number P5-1 in the prepared statement is incremented.
 */
 case OP_SorterNext:    /* jump */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  pOp->opcode = OP_Next;
-#endif
 case OP_Prev:          /* jump */
 case OP_Next: {        /* jump */
   VdbeCursor *pC;
@@ -4555,9 +4535,6 @@ case OP_Next: {        /* jump */
 ** for tables is OP_Insert.
 */
 case OP_SorterInsert:       /* in2 */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  pOp->opcode = OP_IdxInsert;
-#endif
 case OP_IdxInsert: {        /* in2 */
   VdbeCursor *pC;
   BtCursor *pCrsr;
@@ -5784,7 +5761,7 @@ case OP_VOpen: {
     /* Initialize sqlite3_vtab_cursor base class */
     pVtabCursor->pVtab = pVtab;
 
-    /* Initialise vdbe cursor object */
+    /* Initialize vdbe cursor object */
     pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
     if( pCur ){
       pCur->pVtabCursor = pVtabCursor;
@@ -6063,7 +6040,7 @@ case OP_VUpdate: {
       assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
       db->lastRowid = lastRowid = rowid;
     }
-    if( rc==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
+    if( (rc&0xff)==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
       if( pOp->p5==OE_Ignore ){
         rc = SQLITE_OK;
       }else{
diff --git a/lib/libsqlite3/src/vdbeInt.h b/lib/libsqlite3/src/vdbeInt.h
index fac0b2f6ed3..3a5b4028bbd 100644
--- a/lib/libsqlite3/src/vdbeInt.h
+++ b/lib/libsqlite3/src/vdbeInt.h
@@ -19,6 +19,14 @@
 #define _VDBEINT_H_
 
 /*
+** The maximum number of times that a statement will try to reparse
+** itself before giving up and returning SQLITE_SCHEMA.
+*/
+#ifndef SQLITE_MAX_SCHEMA_RETRY
+# define SQLITE_MAX_SCHEMA_RETRY 50
+#endif
+
+/*
 ** SQL is translated into a sequence of instructions to be
 ** executed by a virtual machine.  Each instruction is an instance
 ** of the following structure.
@@ -123,7 +131,7 @@ struct VdbeFrame {
   VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
   void *token;            /* Copy of SubProgram.token */
   i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
-  u16 nCursor;            /* Number of entries in apCsr */
+  int nCursor;            /* Number of entries in apCsr */
   int pc;                 /* Program Counter in parent (calling) frame */
   int nOp;                /* Size of aOp array */
   int nMem;               /* Number of entries in aMem */
@@ -309,7 +317,7 @@ struct Vdbe {
   int nLabel;             /* Number of labels used */
   int *aLabel;            /* Space to hold the labels */
   u16 nResColumn;         /* Number of columns in one row of the result set */
-  u16 nCursor;            /* Number of slots in apCsr[] */
+  int nCursor;            /* Number of slots in apCsr[] */
   u32 magic;              /* Magic number for sanity checking */
   char *zErrMsg;          /* Error message written here */
   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
@@ -429,15 +437,6 @@ int sqlite3VdbeFrameRestore(VdbeFrame *);
 void sqlite3VdbeMemStoreType(Mem *pMem);
 int sqlite3VdbeTransferError(Vdbe *p);
 
-#ifdef SQLITE_OMIT_MERGE_SORT
-# define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
-# define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
-# define sqlite3VdbeSorterClose(Y,Z)
-# define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
-# define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
-# define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
-# define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK
-#else
 int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
 void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
 int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);
@@ -445,7 +444,6 @@ int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *);
 int sqlite3VdbeSorterRewind(sqlite3 *, const VdbeCursor *, int *);
 int sqlite3VdbeSorterWrite(sqlite3 *, const VdbeCursor *, Mem *);
 int sqlite3VdbeSorterCompare(const VdbeCursor *, Mem *, int *);
-#endif
 
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
   void sqlite3VdbeEnter(Vdbe*);
diff --git a/lib/libsqlite3/src/vdbeapi.c b/lib/libsqlite3/src/vdbeapi.c
index b48826680a3..7c861e2d472 100644
--- a/lib/libsqlite3/src/vdbeapi.c
+++ b/lib/libsqlite3/src/vdbeapi.c
@@ -445,7 +445,7 @@ end_of_step:
   assert( p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE );
   if( p->isPrepareV2 && rc!=SQLITE_ROW && rc!=SQLITE_DONE ){
     /* If this statement was prepared using sqlite3_prepare_v2(), and an
-    ** error has occured, then return the error code in p->rc to the
+    ** error has occurred, then return the error code in p->rc to the
     ** caller. Set the error code in the database handle to the same value.
     */ 
     rc = sqlite3VdbeTransferError(p);
@@ -454,14 +454,6 @@ end_of_step:
 }
 
 /*
-** The maximum number of times that a statement will try to reparse
-** itself before giving up and returning SQLITE_SCHEMA.
-*/
-#ifndef SQLITE_MAX_SCHEMA_RETRY
-# define SQLITE_MAX_SCHEMA_RETRY 5
-#endif
-
-/*
 ** This is the top-level implementation of sqlite3_step().  Call
 ** sqlite3Step() to do most of the work.  If a schema error occurs,
 ** call sqlite3Reprepare() and try again.
@@ -1198,7 +1190,7 @@ int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
   if( zName ){
     for(i=0; i<p->nzVar; i++){
       const char *z = p->azVar[i];
-      if( z && memcmp(z,zName,nName)==0 && z[nName]==0 ){
+      if( z && strncmp(z,zName,nName)==0 && z[nName]==0 ){
         return i+1;
       }
     }
diff --git a/lib/libsqlite3/src/vdbeaux.c b/lib/libsqlite3/src/vdbeaux.c
index 3bf8e471482..2c4269a59e6 100644
--- a/lib/libsqlite3/src/vdbeaux.c
+++ b/lib/libsqlite3/src/vdbeaux.c
@@ -17,18 +17,6 @@
 #include "sqliteInt.h"
 #include "vdbeInt.h"
 
-
-
-/*
-** When debugging the code generator in a symbolic debugger, one can
-** set the sqlite3VdbeAddopTrace to 1 and all opcodes will be printed
-** as they are added to the instruction stream.
-*/
-#ifdef SQLITE_DEBUG
-int sqlite3VdbeAddopTrace = 0;
-#endif
-
-
 /*
 ** Create a new virtual database engine.
 */
@@ -158,7 +146,9 @@ int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   pOp->p4type = P4_NOTUSED;
 #ifdef SQLITE_DEBUG
   pOp->zComment = 0;
-  if( sqlite3VdbeAddopTrace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
+  if( p->db->flags & SQLITE_VdbeAddopTrace ){
+    sqlite3VdbePrintOp(0, i, &p->aOp[i]);
+  }
 #endif
 #ifdef VDBE_PROFILE
   pOp->cycles = 0;
@@ -377,7 +367,7 @@ int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
      || (opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1) 
 #endif
      || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
-      && (pOp->p1==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
+      && ((pOp->p1&0xff)==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
     ){
       hasAbort = 1;
       break;
@@ -385,7 +375,7 @@ int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   }
   sqlite3DbFree(v->db, sIter.apSub);
 
-  /* Return true if hasAbort==mayAbort. Or if a malloc failure occured.
+  /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.
   ** If malloc failed, then the while() loop above may not have iterated
   ** through all opcodes and hasAbort may be set incorrectly. Return
   ** true for this case to prevent the assert() in the callers frame
@@ -512,7 +502,7 @@ int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
       pOut->p5 = 0;
 #ifdef SQLITE_DEBUG
       pOut->zComment = 0;
-      if( sqlite3VdbeAddopTrace ){
+      if( p->db->flags & SQLITE_VdbeAddopTrace ){
         sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
       }
 #endif
@@ -1538,7 +1528,7 @@ void sqlite3VdbeMakeReady(
     zEnd = &zCsr[nByte];
   }while( nByte && !db->mallocFailed );
 
-  p->nCursor = (u16)nCursor;
+  p->nCursor = nCursor;
   p->nOnceFlag = nOnce;
   if( p->aVar ){
     p->nVar = (ynVar)nVar;
@@ -1780,7 +1770,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   if( needXcommit && db->xCommitCallback ){
     rc = db->xCommitCallback(db->pCommitArg);
     if( rc ){
-      return SQLITE_CONSTRAINT;
+      return SQLITE_CONSTRAINT_COMMITHOOK;
     }
   }
 
@@ -2017,7 +2007,7 @@ int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
 
   /* If p->iStatement is greater than zero, then this Vdbe opened a 
   ** statement transaction that should be closed here. The only exception
-  ** is that an IO error may have occured, causing an emergency rollback.
+  ** is that an IO error may have occurred, causing an emergency rollback.
   ** In this case (db->nStatement==0), and there is nothing to do.
   */
   if( db->nStatement && p->iStatement ){
@@ -2072,14 +2062,14 @@ int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
 ** violations, return SQLITE_ERROR. Otherwise, SQLITE_OK.
 **
 ** If there are outstanding FK violations and this function returns 
-** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT and write
-** an error message to it. Then return SQLITE_ERROR.
+** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT_FOREIGNKEY
+** and write an error message to it. Then return SQLITE_ERROR.
 */
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
   sqlite3 *db = p->db;
   if( (deferred && db->nDeferredCons>0) || (!deferred && p->nFkConstraint>0) ){
-    p->rc = SQLITE_CONSTRAINT;
+    p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
     p->errorAction = OE_Abort;
     sqlite3SetString(&p->zErrMsg, db, "foreign key constraint failed");
     return SQLITE_ERROR;
@@ -2153,7 +2143,7 @@ int sqlite3VdbeHalt(Vdbe *p){
       **
       ** Even if the statement is read-only, it is important to perform
       ** a statement or transaction rollback operation. If the error 
-      ** occured while writing to the journal, sub-journal or database
+      ** occurred while writing to the journal, sub-journal or database
       ** file as part of an effort to free up cache space (see function
       ** pagerStress() in pager.c), the rollback is required to restore 
       ** the pager to a consistent state.
@@ -2194,7 +2184,7 @@ int sqlite3VdbeHalt(Vdbe *p){
             sqlite3VdbeLeave(p);
             return SQLITE_ERROR;
           }
-          rc = SQLITE_CONSTRAINT;
+          rc = SQLITE_CONSTRAINT_FOREIGNKEY;
         }else{ 
           /* The auto-commit flag is true, the vdbe program was successful 
           ** or hit an 'OR FAIL' constraint and there are no deferred foreign
@@ -2237,7 +2227,7 @@ int sqlite3VdbeHalt(Vdbe *p){
     if( eStatementOp ){
       rc = sqlite3VdbeCloseStatement(p, eStatementOp);
       if( rc ){
-        if( p->rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT ){
+        if( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT ){
           p->rc = rc;
           sqlite3DbFree(db, p->zErrMsg);
           p->zErrMsg = 0;
@@ -2478,7 +2468,7 @@ void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
   sqlite3DbFree(db, p->zSql);
   sqlite3DbFree(db, p->pFree);
 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
-  sqlite3_free(p->zExplain);
+  sqlite3DbFree(db, p->zExplain);
   sqlite3DbFree(db, p->pExplain);
 #endif
 }
@@ -2567,7 +2557,7 @@ int sqlite3VdbeCursorMoveto(VdbeCursor *p){
 ** the blob of data that it corresponds to. In a table record, all serial
 ** types are stored at the start of the record, and the blobs of data at
 ** the end. Hence these functions allow the caller to handle the
-** serial-type and data blob seperately.
+** serial-type and data blob separately.
 **
 ** The following table describes the various storage classes for data:
 **
diff --git a/lib/libsqlite3/src/vdbeblob.c b/lib/libsqlite3/src/vdbeblob.c
index ae77a47ba36..2e8fd8ee744 100644
--- a/lib/libsqlite3/src/vdbeblob.c
+++ b/lib/libsqlite3/src/vdbeblob.c
@@ -313,7 +313,7 @@ int sqlite3_blob_open(
     }
     sqlite3_bind_int64(pBlob->pStmt, 1, iRow);
     rc = blobSeekToRow(pBlob, iRow, &zErr);
-  } while( (++nAttempt)<5 && rc==SQLITE_SCHEMA );
+  } while( (++nAttempt)<SQLITE_MAX_SCHEMA_RETRY && rc==SQLITE_SCHEMA );
 
 blob_open_out:
   if( rc==SQLITE_OK && db->mallocFailed==0 ){
diff --git a/lib/libsqlite3/src/vdbemem.c b/lib/libsqlite3/src/vdbemem.c
index fd964de2e91..8fc222e2de2 100644
--- a/lib/libsqlite3/src/vdbemem.c
+++ b/lib/libsqlite3/src/vdbemem.c
@@ -32,7 +32,9 @@
 ** between formats.
 */
 int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
+#ifndef SQLITE_OMIT_UTF16
   int rc;
+#endif
   assert( (pMem->flags&MEM_RowSet)==0 );
   assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE
            || desiredEnc==SQLITE_UTF16BE );
diff --git a/lib/libsqlite3/src/vdbesort.c b/lib/libsqlite3/src/vdbesort.c
index d51bbf54a3e..fdfc4a79ddc 100644
--- a/lib/libsqlite3/src/vdbesort.c
+++ b/lib/libsqlite3/src/vdbesort.c
@@ -18,7 +18,6 @@
 #include "sqliteInt.h"
 #include "vdbeInt.h"
 
-#ifndef SQLITE_OMIT_MERGE_SORT
 
 typedef struct VdbeSorterIter VdbeSorterIter;
 typedef struct SorterRecord SorterRecord;
@@ -1037,5 +1036,3 @@ int sqlite3VdbeSorterCompare(
   vdbeSorterCompare(pCsr, 1, pVal->z, pVal->n, pKey, nKey, pRes);
   return SQLITE_OK;
 }
-
-#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */
diff --git a/lib/libsqlite3/src/vdbetrace.c b/lib/libsqlite3/src/vdbetrace.c
index 35825c8736e..356277e8d23 100644
--- a/lib/libsqlite3/src/vdbetrace.c
+++ b/lib/libsqlite3/src/vdbetrace.c
@@ -53,6 +53,11 @@ static int findNextHostParameter(const char *zSql, int *pnToken){
 ** then the returned string holds a copy of zRawSql with "-- " prepended
 ** to each line of text.
 **
+** If the SQLITE_TRACE_SIZE_LIMIT macro is defined to an integer, then
+** then long strings and blobs are truncated to that many bytes.  This
+** can be used to prevent unreasonably large trace strings when dealing
+** with large (multi-megabyte) strings and blobs.
+**
 ** The calling function is responsible for making sure the memory returned
 ** is eventually freed.
 **
@@ -123,30 +128,49 @@ char *sqlite3VdbeExpandSql(
       }else if( pVar->flags & MEM_Real ){
         sqlite3XPrintf(&out, "%!.15g", pVar->r);
       }else if( pVar->flags & MEM_Str ){
+        int nOut;  /* Number of bytes of the string text to include in output */
 #ifndef SQLITE_OMIT_UTF16
         u8 enc = ENC(db);
+        Mem utf8;
         if( enc!=SQLITE_UTF8 ){
-          Mem utf8;
           memset(&utf8, 0, sizeof(utf8));
           utf8.db = db;
           sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);
           sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8);
-          sqlite3XPrintf(&out, "'%.*q'", utf8.n, utf8.z);
-          sqlite3VdbeMemRelease(&utf8);
-        }else
+          pVar = &utf8;
+        }
 #endif
-        {
-          sqlite3XPrintf(&out, "'%.*q'", pVar->n, pVar->z);
+        nOut = pVar->n;
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut>SQLITE_TRACE_SIZE_LIMIT ){
+          nOut = SQLITE_TRACE_SIZE_LIMIT;
+          while( nOut<pVar->n && (pVar->z[nOut]&0xc0)==0x80 ){ nOut++; }
         }
+#endif    
+        sqlite3XPrintf(&out, "'%.*q'", nOut, pVar->z);
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut<pVar->n ) sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut);
+#endif
+#ifndef SQLITE_OMIT_UTF16
+        if( enc!=SQLITE_UTF8 ) sqlite3VdbeMemRelease(&utf8);
+#endif
       }else if( pVar->flags & MEM_Zero ){
         sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero);
       }else{
+        int nOut;  /* Number of bytes of the blob to include in output */
         assert( pVar->flags & MEM_Blob );
         sqlite3StrAccumAppend(&out, "x'", 2);
-        for(i=0; i<pVar->n; i++){
+        nOut = pVar->n;
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut>SQLITE_TRACE_SIZE_LIMIT ) nOut = SQLITE_TRACE_SIZE_LIMIT;
+#endif
+        for(i=0; i<nOut; i++){
           sqlite3XPrintf(&out, "%02x", pVar->z[i]&0xff);
         }
         sqlite3StrAccumAppend(&out, "'", 1);
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut<pVar->n ) sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut);
+#endif
       }
     }
   }
diff --git a/lib/libsqlite3/src/wal.c b/lib/libsqlite3/src/wal.c
index 0d7271bf04f..e642ea2105b 100644
--- a/lib/libsqlite3/src/wal.c
+++ b/lib/libsqlite3/src/wal.c
@@ -1207,8 +1207,9 @@ finished:
     ** checkpointing the log file.
     */
     if( pWal->hdr.nPage ){
-      sqlite3_log(SQLITE_OK, "Recovered %d frames from WAL file %s",
-          pWal->hdr.nPage, pWal->zWalName
+      sqlite3_log(SQLITE_NOTICE_RECOVER_WAL,
+          "recovered %d frames from WAL file %s",
+          pWal->hdr.mxFrame, pWal->zWalName
       );
     }
   }
@@ -1722,8 +1723,8 @@ static int walCheckpoint(
       rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
     }
 
-    /* If the database file may grow as a result of this checkpoint, hint
-    ** about the eventual size of the db file to the VFS layer. 
+    /* If the database may grow as a result of this checkpoint, hint
+    ** about the eventual size of the db file to the VFS layer.
     */
     if( rc==SQLITE_OK ){
       i64 nReq = ((i64)mxPage * szPage);
@@ -1733,6 +1734,7 @@ static int walCheckpoint(
       }
     }
 
+
     /* Iterate through the contents of the WAL, copying data to the db file. */
     while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
       i64 iOffset;
@@ -2287,19 +2289,17 @@ void sqlite3WalEndReadTransaction(Wal *pWal){
 }
 
 /*
-** Read a page from the WAL, if it is present in the WAL and if the 
-** current read transaction is configured to use the WAL.  
+** Search the wal file for page pgno. If found, set *piRead to the frame that
+** contains the page. Otherwise, if pgno is not in the wal file, set *piRead
+** to zero.
 **
-** The *pInWal is set to 1 if the requested page is in the WAL and
-** has been loaded.  Or *pInWal is set to 0 if the page was not in 
-** the WAL and needs to be read out of the database.
+** Return SQLITE_OK if successful, or an error code if an error occurs. If an
+** error does occur, the final value of *piRead is undefined.
 */
-int sqlite3WalRead(
+int sqlite3WalFindFrame(
   Wal *pWal,                      /* WAL handle */
   Pgno pgno,                      /* Database page number to read data for */
-  int *pInWal,                    /* OUT: True if data is read from WAL */
-  int nOut,                       /* Size of buffer pOut in bytes */
-  u8 *pOut                        /* Buffer to write page data to */
+  u32 *piRead                     /* OUT: Frame number (or zero) */
 ){
   u32 iRead = 0;                  /* If !=0, WAL frame to return data from */
   u32 iLast = pWal->hdr.mxFrame;  /* Last page in WAL for this reader */
@@ -2315,7 +2315,7 @@ int sqlite3WalRead(
   ** WAL were empty.
   */
   if( iLast==0 || pWal->readLock==0 ){
-    *pInWal = 0;
+    *piRead = 0;
     return SQLITE_OK;
   }
 
@@ -2386,26 +2386,31 @@ int sqlite3WalRead(
   }
 #endif
 
-  /* If iRead is non-zero, then it is the log frame number that contains the
-  ** required page. Read and return data from the log file.
-  */
-  if( iRead ){
-    int sz;
-    i64 iOffset;
-    sz = pWal->hdr.szPage;
-    sz = (sz&0xfe00) + ((sz&0x0001)<<16);
-    testcase( sz<=32768 );
-    testcase( sz>=65536 );
-    iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;
-    *pInWal = 1;
-    /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
-    return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);
-  }
-
-  *pInWal = 0;
+  *piRead = iRead;
   return SQLITE_OK;
 }
 
+/*
+** Read the contents of frame iRead from the wal file into buffer pOut
+** (which is nOut bytes in size). Return SQLITE_OK if successful, or an
+** error code otherwise.
+*/
+int sqlite3WalReadFrame(
+  Wal *pWal,                      /* WAL handle */
+  u32 iRead,                      /* Frame to read */
+  int nOut,                       /* Size of buffer pOut in bytes */
+  u8 *pOut                        /* Buffer to write page data to */
+){
+  int sz;
+  i64 iOffset;
+  sz = pWal->hdr.szPage;
+  sz = (sz&0xfe00) + ((sz&0x0001)<<16);
+  testcase( sz<=32768 );
+  testcase( sz>=65536 );
+  iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;
+  /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
+  return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);
+}
 
 /* 
 ** Return the size of the database in pages (or zero, if unknown).
@@ -2952,6 +2957,9 @@ int sqlite3WalCheckpoint(
   /* Read the wal-index header. */
   if( rc==SQLITE_OK ){
     rc = walIndexReadHdr(pWal, &isChanged);
+    if( isChanged && pWal->pDbFd->pMethods->iVersion>=3 ){
+      sqlite3OsUnfetch(pWal->pDbFd, 0, 0);
+    }
   }
 
   /* Copy data from the log to the database file. */
diff --git a/lib/libsqlite3/src/wal.h b/lib/libsqlite3/src/wal.h
index a848de15276..092546354b3 100644
--- a/lib/libsqlite3/src/wal.h
+++ b/lib/libsqlite3/src/wal.h
@@ -31,7 +31,6 @@
 # define sqlite3WalClose(w,x,y,z)                0
 # define sqlite3WalBeginReadTransaction(y,z)     0
 # define sqlite3WalEndReadTransaction(z)
-# define sqlite3WalRead(v,w,x,y,z)               0
 # define sqlite3WalDbsize(y)                     0
 # define sqlite3WalBeginWriteTransaction(y)      0
 # define sqlite3WalEndWriteTransaction(x)        0
@@ -44,6 +43,7 @@
 # define sqlite3WalExclusiveMode(y,z)            0
 # define sqlite3WalHeapMemory(z)                 0
 # define sqlite3WalFramesize(z)                  0
+# define sqlite3WalFindFrame(x,y,z)              0
 #else
 
 #define WAL_SAVEPOINT_NDATA 4
@@ -71,7 +71,8 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *);
 void sqlite3WalEndReadTransaction(Wal *pWal);
 
 /* Read a page from the write-ahead log, if it is present. */
-int sqlite3WalRead(Wal *pWal, Pgno pgno, int *pInWal, int nOut, u8 *pOut);
+int sqlite3WalFindFrame(Wal *, Pgno, u32 *);
+int sqlite3WalReadFrame(Wal *, u32, int, u8 *);
 
 /* If the WAL is not empty, return the size of the database. */
 Pgno sqlite3WalDbsize(Wal *pWal);
diff --git a/lib/libsqlite3/src/walker.c b/lib/libsqlite3/src/walker.c
index eab96ea24dc..e71ed2ac484 100644
--- a/lib/libsqlite3/src/walker.c
+++ b/lib/libsqlite3/src/walker.c
@@ -113,7 +113,9 @@ int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
 /*
 ** Call sqlite3WalkExpr() for every expression in Select statement p.
 ** Invoke sqlite3WalkSelect() for subqueries in the FROM clause and
-** on the compound select chain, p->pPrior.
+** on the compound select chain, p->pPrior.  Invoke the xSelectCallback()
+** either before or after the walk of expressions and FROM clause, depending
+** on whether pWalker->bSelectDepthFirst is false or true, respectively.
 **
 ** Return WRC_Continue under normal conditions.  Return WRC_Abort if
 ** there is an abort request.
@@ -127,14 +129,23 @@ int sqlite3WalkSelect(Walker *pWalker, Select *p){
   rc = WRC_Continue;
   pWalker->walkerDepth++;
   while( p ){
-    rc = pWalker->xSelectCallback(pWalker, p);
-    if( rc ) break;
+    if( !pWalker->bSelectDepthFirst ){
+       rc = pWalker->xSelectCallback(pWalker, p);
+       if( rc ) break;
+    }
     if( sqlite3WalkSelectExpr(pWalker, p)
      || sqlite3WalkSelectFrom(pWalker, p)
     ){
       pWalker->walkerDepth--;
       return WRC_Abort;
     }
+    if( pWalker->bSelectDepthFirst ){
+      rc = pWalker->xSelectCallback(pWalker, p);
+      /* Depth-first search is currently only used for
+      ** selectAddSubqueryTypeInfo() and that routine always returns
+      ** WRC_Continue (0).  So the following branch is never taken. */
+      if( NEVER(rc) ) break;
+    }
     p = p->pPrior;
   }
   pWalker->walkerDepth--;
diff --git a/lib/libsqlite3/src/where.c b/lib/libsqlite3/src/where.c
index fb3bc5c93cf..e614f4a6d86 100644
--- a/lib/libsqlite3/src/where.c
+++ b/lib/libsqlite3/src/where.c
@@ -98,8 +98,8 @@ struct WhereTerm {
   int leftCursor;         /* Cursor number of X in "X <op> <expr>" */
   union {
     int leftColumn;         /* Column number of X in "X <op> <expr>" */
-    WhereOrInfo *pOrInfo;   /* Extra information if eOperator==WO_OR */
-    WhereAndInfo *pAndInfo; /* Extra information if eOperator==WO_AND */
+    WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */
+    WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
   } u;
   u16 eOperator;          /* A WO_xx value describing <op> */
   u8 wtFlags;             /* TERM_xxx bit flags.  See below */
@@ -140,7 +140,6 @@ struct WhereTerm {
 struct WhereClause {
   Parse *pParse;           /* The parser context */
   WhereMaskSet *pMaskSet;  /* Mapping of table cursor numbers to bitmasks */
-  Bitmask vmask;           /* Bitmask identifying virtual table cursors */
   WhereClause *pOuter;     /* Outer conjunction */
   u8 op;                   /* Split operator.  TK_AND or TK_OR */
   u16 wctrlFlags;          /* Might include WHERE_AND_ONLY */
@@ -227,6 +226,7 @@ struct WhereCost {
 #define WO_ISNULL 0x080
 #define WO_OR     0x100       /* Two or more OR-connected terms */
 #define WO_AND    0x200       /* Two or more AND-connected terms */
+#define WO_EQUIV  0x400       /* Of the form A==B, both columns */
 #define WO_NOOP   0x800       /* This term does not restrict search space */
 
 #define WO_ALL    0xfff       /* Mask of all possible WO_* values */
@@ -253,7 +253,7 @@ struct WhereCost {
 #define WHERE_COLUMN_NULL  0x00080000  /* x IS NULL */
 #define WHERE_INDEXED      0x000f0000  /* Anything that uses an index */
 #define WHERE_NOT_FULLSCAN 0x100f3000  /* Does not do a full table scan */
-#define WHERE_IN_ABLE      0x000f1000  /* Able to support an IN operator */
+#define WHERE_IN_ABLE      0x080f1000  /* Able to support an IN operator */
 #define WHERE_TOP_LIMIT    0x00100000  /* x<EXPR or x<=EXPR constraint */
 #define WHERE_BTM_LIMIT    0x00200000  /* x>EXPR or x>=EXPR constraint */
 #define WHERE_BOTH_LIMIT   0x00300000  /* Both x>EXPR and x<EXPR */
@@ -262,6 +262,8 @@ struct WhereCost {
 #define WHERE_REVERSE      0x01000000  /* Scan in reverse order */
 #define WHERE_UNIQUE       0x02000000  /* Selects no more than one row */
 #define WHERE_ALL_UNIQUE   0x04000000  /* This and all prior have one row */
+#define WHERE_OB_UNIQUE    0x00004000  /* Values in ORDER BY columns are 
+                                       ** different for every output row */
 #define WHERE_VIRTUALTABLE 0x08000000  /* Use virtual-table processing */
 #define WHERE_MULTI_OR     0x10000000  /* OR using multiple indices */
 #define WHERE_TEMP_INDEX   0x20000000  /* Uses an ephemeral index */
@@ -316,7 +318,6 @@ static void whereClauseInit(
   pWC->nTerm = 0;
   pWC->nSlot = ArraySize(pWC->aStatic);
   pWC->a = pWC->aStatic;
-  pWC->vmask = 0;
   pWC->wctrlFlags = wctrlFlags;
 }
 
@@ -563,7 +564,7 @@ static int allowedOp(int op){
 ** Commute a comparison operator.  Expressions of the form "X op Y"
 ** are converted into "Y op X".
 **
-** If left/right precendence rules come into play when determining the
+** If left/right precedence rules come into play when determining the
 ** collating
 ** side of the comparison, it remains associated with the same side after
 ** the commutation. So "Y collate NOCASE op X" becomes 
@@ -629,6 +630,23 @@ static u16 operatorMask(int op){
 ** where X is a reference to the iColumn of table iCur and <op> is one of
 ** the WO_xx operator codes specified by the op parameter.
 ** Return a pointer to the term.  Return 0 if not found.
+**
+** The term returned might by Y=<expr> if there is another constraint in
+** the WHERE clause that specifies that X=Y.  Any such constraints will be
+** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The
+** aEquiv[] array holds X and all its equivalents, with each SQL variable
+** taking up two slots in aEquiv[].  The first slot is for the cursor number
+** and the second is for the column number.  There are 22 slots in aEquiv[]
+** so that means we can look for X plus up to 10 other equivalent values.
+** Hence a search for X will return <expr> if X=A1 and A1=A2 and A2=A3
+** and ... and A9=A10 and A10=<expr>.
+**
+** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"
+** then try for the one with no dependencies on <expr> - in other words where
+** <expr> is a constant expression of some kind.  Only return entries of
+** the form "X <op> Y" where Y is a column in another table if no terms of
+** the form "X <op> <const-expr>" exist.   If no terms with a constant RHS
+** exist, try to return a term that does not use WO_EQUIV.
 */
 static WhereTerm *findTerm(
   WhereClause *pWC,     /* The WHERE clause to be searched */
@@ -638,45 +656,85 @@ static WhereTerm *findTerm(
   u32 op,               /* Mask of WO_xx values describing operator */
   Index *pIdx           /* Must be compatible with this index, if not NULL */
 ){
-  WhereTerm *pTerm;
-  int k;
+  WhereTerm *pTerm;            /* Term being examined as possible result */
+  WhereTerm *pResult = 0;      /* The answer to return */
+  WhereClause *pWCOrig = pWC;  /* Original pWC value */
+  int j, k;                    /* Loop counters */
+  Expr *pX;                /* Pointer to an expression */
+  Parse *pParse;           /* Parsing context */
+  int iOrigCol = iColumn;  /* Original value of iColumn */
+  int nEquiv = 2;          /* Number of entires in aEquiv[] */
+  int iEquiv = 2;          /* Number of entries of aEquiv[] processed so far */
+  int aEquiv[22];          /* iCur,iColumn and up to 10 other equivalents */
+
   assert( iCur>=0 );
-  op &= WO_ALL;
-  for(; pWC; pWC=pWC->pOuter){
-    for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
-      if( pTerm->leftCursor==iCur
-         && (pTerm->prereqRight & notReady)==0
-         && pTerm->u.leftColumn==iColumn
-         && (pTerm->eOperator & op)!=0
-      ){
-        if( iColumn>=0 && pIdx && pTerm->eOperator!=WO_ISNULL ){
-          Expr *pX = pTerm->pExpr;
-          CollSeq *pColl;
-          char idxaff;
-          int j;
-          Parse *pParse = pWC->pParse;
-  
-          idxaff = pIdx->pTable->aCol[iColumn].affinity;
-          if( !sqlite3IndexAffinityOk(pX, idxaff) ) continue;
-  
-          /* Figure out the collation sequence required from an index for
-          ** it to be useful for optimising expression pX. Store this
-          ** value in variable pColl.
-          */
-          assert(pX->pLeft);
-          pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
-          if( pColl==0 ) pColl = pParse->db->pDfltColl;
-  
-          for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
-            if( NEVER(j>=pIdx->nColumn) ) return 0;
+  aEquiv[0] = iCur;
+  aEquiv[1] = iColumn;
+  for(;;){
+    for(pWC=pWCOrig; pWC; pWC=pWC->pOuter){
+      for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
+        if( pTerm->leftCursor==iCur
+          && pTerm->u.leftColumn==iColumn
+        ){
+          if( (pTerm->prereqRight & notReady)==0
+           && (pTerm->eOperator & op & WO_ALL)!=0
+          ){
+            if( iOrigCol>=0 && pIdx && (pTerm->eOperator & WO_ISNULL)==0 ){
+              CollSeq *pColl;
+              char idxaff;
+      
+              pX = pTerm->pExpr;
+              pParse = pWC->pParse;
+              idxaff = pIdx->pTable->aCol[iOrigCol].affinity;
+              if( !sqlite3IndexAffinityOk(pX, idxaff) ){
+                continue;
+              }
+      
+              /* Figure out the collation sequence required from an index for
+              ** it to be useful for optimising expression pX. Store this
+              ** value in variable pColl.
+              */
+              assert(pX->pLeft);
+              pColl = sqlite3BinaryCompareCollSeq(pParse,pX->pLeft,pX->pRight);
+              if( pColl==0 ) pColl = pParse->db->pDfltColl;
+      
+              for(j=0; pIdx->aiColumn[j]!=iOrigCol; j++){
+                if( NEVER(j>=pIdx->nColumn) ) return 0;
+              }
+              if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ){
+                continue;
+              }
+            }
+            if( pTerm->prereqRight==0 && (pTerm->eOperator&WO_EQ)!=0 ){
+              pResult = pTerm;
+              goto findTerm_success;
+            }else if( pResult==0 ){
+              pResult = pTerm;
+            }
+          }
+          if( (pTerm->eOperator & WO_EQUIV)!=0
+           && nEquiv<ArraySize(aEquiv)
+          ){
+            pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
+            assert( pX->op==TK_COLUMN );
+            for(j=0; j<nEquiv; j+=2){
+              if( aEquiv[j]==pX->iTable && aEquiv[j+1]==pX->iColumn ) break;
+            }
+            if( j==nEquiv ){
+              aEquiv[j] = pX->iTable;
+              aEquiv[j+1] = pX->iColumn;
+              nEquiv += 2;
+            }
           }
-          if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
         }
-        return pTerm;
       }
     }
+    if( iEquiv>=nEquiv ) break;
+    iCur = aEquiv[iEquiv++];
+    iColumn = aEquiv[iEquiv++];
   }
-  return 0;
+findTerm_success:
+  return pResult;
 }
 
 /* Forward reference */
@@ -862,7 +920,7 @@ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
 **
 ** CASE 1:
 **
-** If all subterms are of the form T.C=expr for some single column of C
+** If all subterms are of the form T.C=expr for some single column of C and
 ** a single table T (as shown in example B above) then create a new virtual
 ** term that is an equivalent IN expression.  In other words, if the term
 ** being analyzed is:
@@ -950,11 +1008,10 @@ static void exprAnalyzeOrTerm(
   ** Compute the set of tables that might satisfy cases 1 or 2.
   */
   indexable = ~(Bitmask)0;
-  chngToIN = ~(pWC->vmask);
+  chngToIN = ~(Bitmask)0;
   for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
     if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
       WhereAndInfo *pAndInfo;
-      assert( pOrTerm->eOperator==0 );
       assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
       chngToIN = 0;
       pAndInfo = sqlite3DbMallocRaw(db, sizeof(*pAndInfo));
@@ -993,7 +1050,7 @@ static void exprAnalyzeOrTerm(
         b |= getMask(pMaskSet, pOther->leftCursor);
       }
       indexable &= b;
-      if( pOrTerm->eOperator!=WO_EQ ){
+      if( (pOrTerm->eOperator & WO_EQ)==0 ){
         chngToIN = 0;
       }else{
         chngToIN &= b;
@@ -1044,7 +1101,7 @@ static void exprAnalyzeOrTerm(
     for(j=0; j<2 && !okToChngToIN; j++){
       pOrTerm = pOrWc->a;
       for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
-        assert( pOrTerm->eOperator==WO_EQ );
+        assert( pOrTerm->eOperator & WO_EQ );
         pOrTerm->wtFlags &= ~TERM_OR_OK;
         if( pOrTerm->leftCursor==iCursor ){
           /* This is the 2-bit case and we are on the second iteration and
@@ -1070,7 +1127,7 @@ static void exprAnalyzeOrTerm(
         /* No candidate table+column was found.  This can only occur
         ** on the second iteration */
         assert( j==1 );
-        assert( (chngToIN&(chngToIN-1))==0 );
+        assert( IsPowerOfTwo(chngToIN) );
         assert( chngToIN==getMask(pMaskSet, iCursor) );
         break;
       }
@@ -1080,7 +1137,7 @@ static void exprAnalyzeOrTerm(
       ** table and column is common to every term in the OR clause */
       okToChngToIN = 1;
       for(; i>=0 && okToChngToIN; i--, pOrTerm++){
-        assert( pOrTerm->eOperator==WO_EQ );
+        assert( pOrTerm->eOperator & WO_EQ );
         if( pOrTerm->leftCursor!=iCursor ){
           pOrTerm->wtFlags &= ~TERM_OR_OK;
         }else if( pOrTerm->u.leftColumn!=iColumn ){
@@ -1116,7 +1173,7 @@ static void exprAnalyzeOrTerm(
 
       for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
         if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
-        assert( pOrTerm->eOperator==WO_EQ );
+        assert( pOrTerm->eOperator & WO_EQ );
         assert( pOrTerm->leftCursor==iCursor );
         assert( pOrTerm->u.leftColumn==iColumn );
         pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
@@ -1146,7 +1203,6 @@ static void exprAnalyzeOrTerm(
 }
 #endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
 
-
 /*
 ** The input to this routine is an WhereTerm structure with only the
 ** "pExpr" field filled in.  The job of this routine is to analyze the
@@ -1215,17 +1271,19 @@ static void exprAnalyze(
   pTerm->leftCursor = -1;
   pTerm->iParent = -1;
   pTerm->eOperator = 0;
-  if( allowedOp(op) && (pTerm->prereqRight & prereqLeft)==0 ){
+  if( allowedOp(op) ){
     Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
     Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
+    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
     if( pLeft->op==TK_COLUMN ){
       pTerm->leftCursor = pLeft->iTable;
       pTerm->u.leftColumn = pLeft->iColumn;
-      pTerm->eOperator = operatorMask(op);
+      pTerm->eOperator = operatorMask(op) & opMask;
     }
     if( pRight && pRight->op==TK_COLUMN ){
       WhereTerm *pNew;
       Expr *pDup;
+      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
       if( pTerm->leftCursor>=0 ){
         int idxNew;
         pDup = sqlite3ExprDup(db, pExpr, 0);
@@ -1240,6 +1298,13 @@ static void exprAnalyze(
         pTerm = &pWC->a[idxTerm];
         pTerm->nChild = 1;
         pTerm->wtFlags |= TERM_COPIED;
+        if( pExpr->op==TK_EQ
+         && !ExprHasProperty(pExpr, EP_FromJoin)
+         && OptimizationEnabled(db, SQLITE_Transitive)
+        ){
+          pTerm->eOperator |= WO_EQUIV;
+          eExtraOp = WO_EQUIV;
+        }
       }else{
         pDup = pExpr;
         pNew = pTerm;
@@ -1251,7 +1316,7 @@ static void exprAnalyze(
       testcase( (prereqLeft | extraRight) != prereqLeft );
       pNew->prereqRight = prereqLeft | extraRight;
       pNew->prereqAll = prereqAll;
-      pNew->eOperator = operatorMask(pDup->op);
+      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
     }
   }
 
@@ -1710,7 +1775,7 @@ static void bestOrClauseIndex(WhereBestIdx *p){
 
   /* Search the WHERE clause terms for a usable WO_OR term. */
   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
-    if( pTerm->eOperator==WO_OR 
+    if( (pTerm->eOperator & WO_OR)!=0
      && ((pTerm->prereqAll & ~maskSrc) & p->notReady)==0
      && (pTerm->u.pOrInfo->indexable & maskSrc)!=0 
     ){
@@ -1731,7 +1796,7 @@ static void bestOrClauseIndex(WhereBestIdx *p){
         WHERETRACE(("... Multi-index OR testing for term %d of %d....\n", 
           (pOrTerm - pOrWC->a), (pTerm - pWC->a)
         ));
-        if( pOrTerm->eOperator==WO_AND ){
+        if( (pOrTerm->eOperator& WO_AND)!=0 ){
           sBOI.pWC = &pOrTerm->u.pAndInfo->wc;
           bestIndex(&sBOI);
         }else if( pOrTerm->leftCursor==iCur ){
@@ -1792,7 +1857,7 @@ static int termCanDriveIndex(
 ){
   char aff;
   if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
-  if( pTerm->eOperator!=WO_EQ ) return 0;
+  if( (pTerm->eOperator & WO_EQ)==0 ) return 0;
   if( (pTerm->prereqRight & notReady)!=0 ) return 0;
   aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
   if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
@@ -2054,10 +2119,10 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
   ** to this virtual table */
   for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
     if( pTerm->leftCursor != pSrc->iCursor ) continue;
-    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
-    testcase( pTerm->eOperator==WO_IN );
-    testcase( pTerm->eOperator==WO_ISNULL );
-    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    if( pTerm->eOperator & (WO_ISNULL) ) continue;
     if( pTerm->wtFlags & TERM_VNULL ) continue;
     nTerm++;
   }
@@ -2105,15 +2170,18 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
                                                                    pUsage;
 
   for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    u8 op;
     if( pTerm->leftCursor != pSrc->iCursor ) continue;
-    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
-    testcase( pTerm->eOperator==WO_IN );
-    testcase( pTerm->eOperator==WO_ISNULL );
-    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    if( pTerm->eOperator & (WO_ISNULL) ) continue;
     if( pTerm->wtFlags & TERM_VNULL ) continue;
     pIdxCons[j].iColumn = pTerm->u.leftColumn;
     pIdxCons[j].iTermOffset = i;
-    pIdxCons[j].op = (u8)pTerm->eOperator;
+    op = (u8)pTerm->eOperator & WO_ALL;
+    if( op==WO_IN ) op = WO_EQ;
+    pIdxCons[j].op = op;
     /* The direct assignment in the previous line is possible only because
     ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
     ** following asserts verify this fact. */
@@ -2123,7 +2191,7 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
     assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
     assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
     assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
-    assert( pTerm->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
+    assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
     j++;
   }
   for(i=0; i<nOrderBy; i++){
@@ -2209,6 +2277,7 @@ static void bestVirtualIndex(WhereBestIdx *p){
   WhereTerm *pTerm;
   int i, j;
   int nOrderBy;
+  int bAllowIN;                   /* Allow IN optimizations */
   double rCost;
 
   /* Make sure wsFlags is initialized to some sane value. Otherwise, if the 
@@ -2243,59 +2312,106 @@ static void bestVirtualIndex(WhereBestIdx *p){
   assert( pTab->azModuleArg && pTab->azModuleArg[0] );
   assert( sqlite3GetVTable(pParse->db, pTab) );
 
-  /* Set the aConstraint[].usable fields and initialize all 
-  ** output variables to zero.
-  **
-  ** aConstraint[].usable is true for constraints where the right-hand
-  ** side contains only references to tables to the left of the current
-  ** table.  In other words, if the constraint is of the form:
-  **
-  **           column = expr
-  **
-  ** and we are evaluating a join, then the constraint on column is 
-  ** only valid if all tables referenced in expr occur to the left
-  ** of the table containing column.
-  **
-  ** The aConstraints[] array contains entries for all constraints
-  ** on the current table.  That way we only have to compute it once
-  ** even though we might try to pick the best index multiple times.
-  ** For each attempt at picking an index, the order of tables in the
-  ** join might be different so we have to recompute the usable flag
-  ** each time.
+  /* Try once or twice.  On the first attempt, allow IN optimizations.
+  ** If an IN optimization is accepted by the virtual table xBestIndex
+  ** method, but the  pInfo->aConstrainUsage.omit flag is not set, then
+  ** the query will not work because it might allow duplicate rows in
+  ** output.  In that case, run the xBestIndex method a second time
+  ** without the IN constraints.  Usually this loop only runs once.
+  ** The loop will exit using a "break" statement.
   */
-  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-  pUsage = pIdxInfo->aConstraintUsage;
-  for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
-    j = pIdxCons->iTermOffset;
-    pTerm = &pWC->a[j];
-    pIdxCons->usable = (pTerm->prereqRight&p->notReady) ? 0 : 1;
-  }
-  memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
-  if( pIdxInfo->needToFreeIdxStr ){
-    sqlite3_free(pIdxInfo->idxStr);
-  }
-  pIdxInfo->idxStr = 0;
-  pIdxInfo->idxNum = 0;
-  pIdxInfo->needToFreeIdxStr = 0;
-  pIdxInfo->orderByConsumed = 0;
-  /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */
-  pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2);
-  nOrderBy = pIdxInfo->nOrderBy;
-  if( !p->pOrderBy ){
-    pIdxInfo->nOrderBy = 0;
-  }
-
-  if( vtabBestIndex(pParse, pTab, pIdxInfo) ){
-    return;
-  }
+  for(bAllowIN=1; 1; bAllowIN--){
+    assert( bAllowIN==0 || bAllowIN==1 );
 
-  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-  for(i=0; i<pIdxInfo->nConstraint; i++){
-    if( pUsage[i].argvIndex>0 ){
-      p->cost.used |= pWC->a[pIdxCons[i].iTermOffset].prereqRight;
+    /* Set the aConstraint[].usable fields and initialize all 
+    ** output variables to zero.
+    **
+    ** aConstraint[].usable is true for constraints where the right-hand
+    ** side contains only references to tables to the left of the current
+    ** table.  In other words, if the constraint is of the form:
+    **
+    **           column = expr
+    **
+    ** and we are evaluating a join, then the constraint on column is 
+    ** only valid if all tables referenced in expr occur to the left
+    ** of the table containing column.
+    **
+    ** The aConstraints[] array contains entries for all constraints
+    ** on the current table.  That way we only have to compute it once
+    ** even though we might try to pick the best index multiple times.
+    ** For each attempt at picking an index, the order of tables in the
+    ** join might be different so we have to recompute the usable flag
+    ** each time.
+    */
+    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+    pUsage = pIdxInfo->aConstraintUsage;
+    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
+      j = pIdxCons->iTermOffset;
+      pTerm = &pWC->a[j];
+      if( (pTerm->prereqRight&p->notReady)==0
+       && (bAllowIN || (pTerm->eOperator & WO_IN)==0)
+      ){
+        pIdxCons->usable = 1;
+      }else{
+        pIdxCons->usable = 0;
+      }
+    }
+    memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
+    if( pIdxInfo->needToFreeIdxStr ){
+      sqlite3_free(pIdxInfo->idxStr);
+    }
+    pIdxInfo->idxStr = 0;
+    pIdxInfo->idxNum = 0;
+    pIdxInfo->needToFreeIdxStr = 0;
+    pIdxInfo->orderByConsumed = 0;
+    /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */
+    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2);
+    nOrderBy = pIdxInfo->nOrderBy;
+    if( !p->pOrderBy ){
+      pIdxInfo->nOrderBy = 0;
     }
+  
+    if( vtabBestIndex(pParse, pTab, pIdxInfo) ){
+      return;
+    }
+  
+    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
+      if( pUsage[i].argvIndex>0 ){
+        j = pIdxCons->iTermOffset;
+        pTerm = &pWC->a[j];
+        p->cost.used |= pTerm->prereqRight;
+        if( (pTerm->eOperator & WO_IN)!=0 ){
+          if( pUsage[i].omit==0 ){
+            /* Do not attempt to use an IN constraint if the virtual table
+            ** says that the equivalent EQ constraint cannot be safely omitted.
+            ** If we do attempt to use such a constraint, some rows might be
+            ** repeated in the output. */
+            break;
+          }
+          /* A virtual table that is constrained by an IN clause may not
+          ** consume the ORDER BY clause because (1) the order of IN terms
+          ** is not necessarily related to the order of output terms and
+          ** (2) Multiple outputs from a single IN value will not merge
+          ** together.  */
+          pIdxInfo->orderByConsumed = 0;
+        }
+      }
+    }
+    if( i>=pIdxInfo->nConstraint ) break;
   }
 
+  /* The orderByConsumed signal is only valid if all outer loops collectively
+  ** generate just a single row of output.
+  */
+  if( pIdxInfo->orderByConsumed ){
+    for(i=0; i<p->i; i++){
+      if( (p->aLevel[i].plan.wsFlags & WHERE_UNIQUE)==0 ){
+        pIdxInfo->orderByConsumed = 0;
+      }
+    }
+  }
+  
   /* If there is an ORDER BY clause, and the selected virtual table index
   ** does not satisfy it, increase the cost of the scan accordingly. This
   ** matches the processing for non-virtual tables in bestBtreeIndex().
@@ -2590,24 +2706,24 @@ static int whereRangeScanEst(
     if( pLower ){
       Expr *pExpr = pLower->pExpr->pRight;
       rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
-      assert( pLower->eOperator==WO_GT || pLower->eOperator==WO_GE );
+      assert( (pLower->eOperator & (WO_GT|WO_GE))!=0 );
       if( rc==SQLITE_OK
        && whereKeyStats(pParse, p, pRangeVal, 0, a)==SQLITE_OK
       ){
         iLower = a[0];
-        if( pLower->eOperator==WO_GT ) iLower += a[1];
+        if( (pLower->eOperator & WO_GT)!=0 ) iLower += a[1];
       }
       sqlite3ValueFree(pRangeVal);
     }
     if( rc==SQLITE_OK && pUpper ){
       Expr *pExpr = pUpper->pExpr->pRight;
       rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
-      assert( pUpper->eOperator==WO_LT || pUpper->eOperator==WO_LE );
+      assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
       if( rc==SQLITE_OK
        && whereKeyStats(pParse, p, pRangeVal, 1, a)==SQLITE_OK
       ){
         iUpper = a[0];
-        if( pUpper->eOperator==WO_LE ) iUpper += a[1];
+        if( (pUpper->eOperator & WO_LE)!=0 ) iUpper += a[1];
       }
       sqlite3ValueFree(pRangeVal);
     }
@@ -2797,7 +2913,8 @@ static int isSortingIndex(
   WhereBestIdx *p,    /* Best index search context */
   Index *pIdx,        /* The index we are testing */
   int base,           /* Cursor number for the table to be sorted */
-  int *pbRev          /* Set to 1 for reverse-order scan of pIdx */
+  int *pbRev,         /* Set to 1 for reverse-order scan of pIdx */
+  int *pbObUnique     /* ORDER BY column values will different in every row */
 ){
   int i;                        /* Number of pIdx terms used */
   int j;                        /* Number of ORDER BY terms satisfied */
@@ -2811,12 +2928,16 @@ static int isSortingIndex(
   int nPriorSat;                /* ORDER BY terms satisfied by outer loops */
   int seenRowid = 0;            /* True if an ORDER BY rowid term is seen */
   int uniqueNotNull;            /* pIdx is UNIQUE with all terms are NOT NULL */
+  int outerObUnique;            /* Outer loops generate different values in
+                                ** every row for the ORDER BY columns */
 
   if( p->i==0 ){
     nPriorSat = 0;
+    outerObUnique = 1;
   }else{
+    u32 wsFlags = p->aLevel[p->i-1].plan.wsFlags;
     nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
-    if( (p->aLevel[p->i-1].plan.wsFlags & WHERE_ORDERED)==0 ){
+    if( (wsFlags & WHERE_ORDERED)==0 ){
       /* This loop cannot be ordered unless the next outer loop is
       ** also ordered */
       return nPriorSat;
@@ -2826,6 +2947,9 @@ static int isSortingIndex(
       ** optimization is disabled */
       return nPriorSat;
     }
+    testcase( wsFlags & WHERE_OB_UNIQUE );
+    testcase( wsFlags & WHERE_ALL_UNIQUE );
+    outerObUnique = (wsFlags & (WHERE_OB_UNIQUE|WHERE_ALL_UNIQUE))!=0;
   }
   pOrderBy = p->pOrderBy;
   assert( pOrderBy!=0 );
@@ -2915,12 +3039,9 @@ static int isSortingIndex(
                            WO_EQ|WO_ISNULL|WO_IN, pIdx);
     if( pConstraint==0 ){
       isEq = 0;
-    }else if( pConstraint->eOperator==WO_IN ){
-      /* Constraints of the form: "X IN ..." cannot be used with an ORDER BY
-      ** because we do not know in what order the values on the RHS of the IN
-      ** operator will occur. */
-      break;
-    }else if( pConstraint->eOperator==WO_ISNULL ){
+    }else if( (pConstraint->eOperator & WO_IN)!=0 ){
+      isEq = 0;
+    }else if( (pConstraint->eOperator & WO_ISNULL)!=0 ){
       uniqueNotNull = 0;
       isEq = 1;  /* "X IS NULL" means X has only a single value */
     }else if( pConstraint->prereqRight==0 ){
@@ -2970,11 +3091,26 @@ static int isSortingIndex(
       uniqueNotNull = 0;
     }
   }
+  if( seenRowid ){
+    uniqueNotNull = 1;
+  }else if( uniqueNotNull==0 || i<pIdx->nColumn ){
+    uniqueNotNull = 0;
+  }
 
   /* If we have not found at least one ORDER BY term that matches the
   ** index, then show no progress. */
   if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat;
 
+  /* Either the outer queries must generate rows where there are no two
+  ** rows with the same values in all ORDER BY columns, or else this
+  ** loop must generate just a single row of output.  Example:  Suppose
+  ** the outer loops generate A=1 and A=1, and this loop generates B=3
+  ** and B=4.  Then without the following test, ORDER BY A,B would 
+  ** generate the wrong order output: 1,3 1,4 1,3 1,4
+  */
+  if( outerObUnique==0 && uniqueNotNull==0 ) return nPriorSat;
+  *pbObUnique = uniqueNotNull;
+
   /* Return the necessary scan order back to the caller */
   *pbRev = sortOrder & 1;
 
@@ -2982,7 +3118,7 @@ static int isSortingIndex(
   ** possible for a single row from this table to match, then skip over
   ** any additional ORDER BY terms dealing with this table.
   */
-  if( seenRowid || (uniqueNotNull && i>=pIdx->nColumn) ){
+  if( uniqueNotNull ){
     /* Advance j over additional ORDER BY terms associated with base */
     WhereMaskSet *pMS = p->pWC->pMaskSet;
     Bitmask m = ~getMask(pMS, base);
@@ -3223,8 +3359,8 @@ static void bestBtreeIndex(WhereBestIdx *p){
     ** indicate this to the caller.
     **
     ** Otherwise, if the search may find more than one row, test to see if
-    ** there is a range constraint on indexed column (pc.plan.nEq+1) that can be 
-    ** optimized using the index. 
+    ** there is a range constraint on indexed column (pc.plan.nEq+1) that
+    ** can be optimized using the index. 
     */
     if( pc.plan.nEq==pProbe->nColumn && pProbe->onError!=OE_None ){
       testcase( pc.plan.wsFlags & WHERE_COLUMN_IN );
@@ -3266,12 +3402,14 @@ static void bestBtreeIndex(WhereBestIdx *p){
     ** variable.  */
     if( bSort && (pSrc->jointype & JT_LEFT)==0 ){
       int bRev = 2;
-      WHERETRACE(("      --> before isSortingIndex: nPriorSat=%d\n",nPriorSat));
-      pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev);
-      WHERETRACE(("      --> after  isSortingIndex: bRev=%d nOBSat=%d\n",
-                  bRev, pc.plan.nOBSat));
+      int bObUnique = 0;
+      WHERETRACE(("      --> before isSortIndex: nPriorSat=%d\n",nPriorSat));
+      pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev, &bObUnique);
+      WHERETRACE(("      --> after  isSortIndex: bRev=%d bObU=%d nOBSat=%d\n",
+                  bRev, bObUnique, pc.plan.nOBSat));
       if( nPriorSat<pc.plan.nOBSat || (pc.plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
         pc.plan.wsFlags |= WHERE_ORDERED;
+        if( bObUnique ) pc.plan.wsFlags |= WHERE_OB_UNIQUE;
       }
       if( nOrderBy==pc.plan.nOBSat ){
         bSort = 0;
@@ -3333,12 +3471,13 @@ static void bestBtreeIndex(WhereBestIdx *p){
      && pFirstTerm!=0 && aiRowEst[1]>1 ){
       assert( (pFirstTerm->eOperator & (WO_EQ|WO_ISNULL|WO_IN))!=0 );
       if( pFirstTerm->eOperator & (WO_EQ|WO_ISNULL) ){
-        testcase( pFirstTerm->eOperator==WO_EQ );
-        testcase( pFirstTerm->eOperator==WO_ISNULL );
+        testcase( pFirstTerm->eOperator & WO_EQ );
+        testcase( pFirstTerm->eOperator & WO_EQUIV );
+        testcase( pFirstTerm->eOperator & WO_ISNULL );
         whereEqualScanEst(pParse, pProbe, pFirstTerm->pExpr->pRight,
                           &pc.plan.nRow);
       }else if( bInEst==0 ){
-        assert( pFirstTerm->eOperator==WO_IN );
+        assert( pFirstTerm->eOperator & WO_IN );
         whereInScanEst(pParse, pProbe, pFirstTerm->pExpr->x.pList,
                        &pc.plan.nRow);
       }
@@ -3364,7 +3503,8 @@ static void bestBtreeIndex(WhereBestIdx *p){
     ** So this computation assumes table records are about twice as big
     ** as index records
     */
-    if( (pc.plan.wsFlags&~(WHERE_REVERSE|WHERE_ORDERED))==WHERE_IDX_ONLY
+    if( (pc.plan.wsFlags&~(WHERE_REVERSE|WHERE_ORDERED|WHERE_OB_UNIQUE))
+                                                              ==WHERE_IDX_ONLY
      && (pWC->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
      && sqlite3GlobalConfig.bUseCis
      && OptimizationEnabled(pParse->db, SQLITE_CoverIdxScan)
@@ -3485,7 +3625,7 @@ static void bestBtreeIndex(WhereBestIdx *p){
             ** selective in practice, on average. */
             pc.plan.nRow /= 3;
           }
-        }else if( pTerm->eOperator!=WO_NOOP ){
+        }else if( (pTerm->eOperator & WO_NOOP)==0 ){
           /* Any other expression lowers the output row count by half */
           pc.plan.nRow /= 2;
         }
@@ -3524,7 +3664,7 @@ static void bestBtreeIndex(WhereBestIdx *p){
   /* If there is no ORDER BY clause and the SQLITE_ReverseOrder flag
   ** is set, then reverse the order that the index will be scanned
   ** in. This is used for application testing, to help find cases
-  ** where application behaviour depends on the (undefined) order that
+  ** where application behavior depends on the (undefined) order that
   ** SQLite outputs rows in in the absence of an ORDER BY clause.  */
   if( !p->pOrderBy && pParse->db->flags & SQLITE_ReverseOrder ){
     p->cost.plan.wsFlags |= WHERE_REVERSE;
@@ -3537,8 +3677,9 @@ static void bestBtreeIndex(WhereBestIdx *p){
        || p->cost.plan.u.pIdx==pSrc->pIndex 
   );
 
-  WHERETRACE(("   best index is: %s\n",
-         p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk"));
+  WHERETRACE(("   best index is %s cost=%.1f\n",
+         p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk",
+         p->cost.rCost));
   
   bestOrClauseIndex(p);
   bestAutomaticIndex(p);
@@ -3563,7 +3704,8 @@ static void bestIndex(WhereBestIdx *p){
     sqlite3_index_info *pIdxInfo = 0;
     p->ppIdxInfo = &pIdxInfo;
     bestVirtualIndex(p);
-    if( pIdxInfo->needToFreeIdxStr ){
+    assert( pIdxInfo!=0 || p->pParse->db->mallocFailed );
+    if( pIdxInfo && pIdxInfo->needToFreeIdxStr ){
       sqlite3_free(pIdxInfo->idxStr);
     }
     sqlite3DbFree(p->pParse->db, pIdxInfo);
@@ -3669,7 +3811,8 @@ static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
 static int codeEqualityTerm(
   Parse *pParse,      /* The parsing context */
   WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
-  WhereLevel *pLevel, /* When level of the FROM clause we are working on */
+  WhereLevel *pLevel, /* The level of the FROM clause we are working on */
+  int iEq,            /* Index of the equality term within this level */
   int iTarget         /* Attempt to leave results in this register */
 ){
   Expr *pX = pTerm->pExpr;
@@ -3687,12 +3830,26 @@ static int codeEqualityTerm(
     int eType;
     int iTab;
     struct InLoop *pIn;
+    u8 bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
 
+    if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 
+      && pLevel->plan.u.pIdx->aSortOrder[iEq]
+    ){
+      testcase( iEq==0 );
+      testcase( iEq==pLevel->plan.u.pIdx->nColumn-1 );
+      testcase( iEq>0 && iEq+1<pLevel->plan.u.pIdx->nColumn );
+      testcase( bRev );
+      bRev = !bRev;
+    }
     assert( pX->op==TK_IN );
     iReg = iTarget;
     eType = sqlite3FindInIndex(pParse, pX, 0);
+    if( eType==IN_INDEX_INDEX_DESC ){
+      testcase( bRev );
+      bRev = !bRev;
+    }
     iTab = pX->iTable;
-    sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
+    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
     assert( pLevel->plan.wsFlags & WHERE_IN_ABLE );
     if( pLevel->u.in.nIn==0 ){
       pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
@@ -3710,6 +3867,7 @@ static int codeEqualityTerm(
       }else{
         pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
       }
+      pIn->eEndLoopOp = bRev ? OP_Prev : OP_Next;
       sqlite3VdbeAddOp1(v, OP_IsNull, iReg);
     }else{
       pLevel->u.in.nIn = 0;
@@ -3804,7 +3962,7 @@ static int codeAllEqualityTerms(
     ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
     testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
     testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
+    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, regBase+j);
     if( r1!=regBase+j ){
       if( nReg==1 ){
         sqlite3ReleaseTempReg(pParse, regBase);
@@ -4014,6 +4172,7 @@ static Bitmask codeOneLoopStart(
   int addrCont;                   /* Jump here to continue with next cycle */
   int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
   int iReleaseReg = 0;      /* Temp register to free before returning */
+  Bitmask newNotReady;      /* Return value */
 
   pParse = pWInfo->pParse;
   v = pParse->pVdbe;
@@ -4024,6 +4183,7 @@ static Bitmask codeOneLoopStart(
   bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
   omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0 
            && (wctrlFlags & WHERE_FORCE_TABLE)==0;
+  VdbeNoopComment((v, "Begin Join Loop %d", iLevel));
 
   /* Create labels for the "break" and "continue" instructions
   ** for the current loop.  Jump to addrBrk to break out of a loop.
@@ -4064,6 +4224,7 @@ static Bitmask codeOneLoopStart(
     **          to access the data.
     */
     int iReg;   /* P3 Value for OP_VFilter */
+    int addrNotFound;
     sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
     int nConstraint = pVtabIdx->nConstraint;
     struct sqlite3_index_constraint_usage *aUsage =
@@ -4073,11 +4234,18 @@ static Bitmask codeOneLoopStart(
 
     sqlite3ExprCachePush(pParse);
     iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+    addrNotFound = pLevel->addrBrk;
     for(j=1; j<=nConstraint; j++){
       for(k=0; k<nConstraint; k++){
         if( aUsage[k].argvIndex==j ){
-          int iTerm = aConstraint[k].iTermOffset;
-          sqlite3ExprCode(pParse, pWC->a[iTerm].pExpr->pRight, iReg+j+1);
+          int iTarget = iReg+j+1;
+          pTerm = &pWC->a[aConstraint[k].iTermOffset];
+          if( pTerm->eOperator & WO_IN ){
+            codeEqualityTerm(pParse, pTerm, pLevel, k, iTarget);
+            addrNotFound = pLevel->addrNxt;
+          }else{
+            sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
+          }
           break;
         }
       }
@@ -4085,7 +4253,7 @@ static Bitmask codeOneLoopStart(
     }
     sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg);
     sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
-    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrBrk, iReg, pVtabIdx->idxStr,
+    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg, pVtabIdx->idxStr,
                       pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
     pVtabIdx->needToFreeIdxStr = 0;
     for(j=0; j<nConstraint; j++){
@@ -4112,13 +4280,13 @@ static Bitmask codeOneLoopStart(
     pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
     assert( pTerm!=0 );
     assert( pTerm->pExpr!=0 );
-    assert( pTerm->leftCursor==iCur );
     assert( omitTable==0 );
     testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, iReleaseReg);
+    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, iReleaseReg);
     addrNxt = pLevel->addrNxt;
     sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt);
     sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
+    sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
     sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
     VdbeComment((v, "pk"));
     pLevel->op = OP_Noop;
@@ -4503,7 +4671,7 @@ static Bitmask codeOneLoopStart(
    
     pTerm = pLevel->plan.u.pTerm;
     assert( pTerm!=0 );
-    assert( pTerm->eOperator==WO_OR );
+    assert( pTerm->eOperator & WO_OR );
     assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
     pOrWc = &pTerm->u.pOrInfo->wc;
     pLevel->op = OP_Return;
@@ -4558,6 +4726,10 @@ static Bitmask codeOneLoopStart(
     ** the "interesting" terms of z - terms that did not originate in the
     ** ON or USING clause of a LEFT JOIN, and terms that are usable as 
     ** indices.
+    **
+    ** This optimization also only applies if the (x1 OR x2 OR ...) term
+    ** is not contained in the ON clause of a LEFT JOIN.
+    ** See ticket http://www.sqlite.org/src/info/f2369304e4
     */
     if( pWC->nTerm>1 ){
       int iTerm;
@@ -4576,10 +4748,10 @@ static Bitmask codeOneLoopStart(
 
     for(ii=0; ii<pOrWc->nTerm; ii++){
       WhereTerm *pOrTerm = &pOrWc->a[ii];
-      if( pOrTerm->leftCursor==iCur || pOrTerm->eOperator==WO_AND ){
+      if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
         WhereInfo *pSubWInfo;          /* Info for single OR-term scan */
         Expr *pOrExpr = pOrTerm->pExpr;
-        if( pAndExpr ){
+        if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
           pAndExpr->pLeft = pOrExpr;
           pOrExpr = pAndExpr;
         }
@@ -4666,7 +4838,7 @@ static Bitmask codeOneLoopStart(
     pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
     pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
   }
-  notReady &= ~getMask(pWC->pMaskSet, iCur);
+  newNotReady = notReady & ~getMask(pWC->pMaskSet, iCur);
 
   /* Insert code to test every subexpression that can be completely
   ** computed using the current set of tables.
@@ -4680,7 +4852,7 @@ static Bitmask codeOneLoopStart(
     testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* IMP: R-30575-11662 */
     testcase( pTerm->wtFlags & TERM_CODED );
     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-    if( (pTerm->prereqAll & notReady)!=0 ){
+    if( (pTerm->prereqAll & newNotReady)!=0 ){
       testcase( pWInfo->untestedTerms==0
                && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
       pWInfo->untestedTerms = 1;
@@ -4695,6 +4867,33 @@ static Bitmask codeOneLoopStart(
     pTerm->wtFlags |= TERM_CODED;
   }
 
+  /* Insert code to test for implied constraints based on transitivity
+  ** of the "==" operator.
+  **
+  ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
+  ** and we are coding the t1 loop and the t2 loop has not yet coded,
+  ** then we cannot use the "t1.a=t2.b" constraint, but we can code
+  ** the implied "t1.a=123" constraint.
+  */
+  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+    Expr *pE;
+    WhereTerm *pAlt;
+    Expr sEq;
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue;
+    if( pTerm->leftCursor!=iCur ) continue;
+    pE = pTerm->pExpr;
+    assert( !ExprHasProperty(pE, EP_FromJoin) );
+    assert( (pTerm->prereqRight & newNotReady)!=0 );
+    pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
+    if( pAlt==0 ) continue;
+    if( pAlt->wtFlags & (TERM_CODED) ) continue;
+    VdbeNoopComment((v, "begin transitive constraint"));
+    sEq = *pAlt->pExpr;
+    sEq.pLeft = pE->pLeft;
+    sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL);
+  }
+
   /* For a LEFT OUTER JOIN, generate code that will record the fact that
   ** at least one row of the right table has matched the left table.  
   */
@@ -4707,7 +4906,7 @@ static Bitmask codeOneLoopStart(
       testcase( pTerm->wtFlags & TERM_VIRTUAL );  /* IMP: R-30575-11662 */
       testcase( pTerm->wtFlags & TERM_CODED );
       if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-      if( (pTerm->prereqAll & notReady)!=0 ){
+      if( (pTerm->prereqAll & newNotReady)!=0 ){
         assert( pWInfo->untestedTerms );
         continue;
       }
@@ -4718,7 +4917,7 @@ static Bitmask codeOneLoopStart(
   }
   sqlite3ReleaseTempReg(pParse, iReleaseReg);
 
-  return notReady;
+  return newNotReady;
 }
 
 #if defined(SQLITE_TEST)
@@ -4954,24 +5153,13 @@ WhereInfo *sqlite3WhereBegin(
   ** bitmask for all tables to the left of the join.  Knowing the bitmask
   ** for all tables to the left of a left join is important.  Ticket #3015.
   **
-  ** Configure the WhereClause.vmask variable so that bits that correspond
-  ** to virtual table cursors are set. This is used to selectively disable 
-  ** the OR-to-IN transformation in exprAnalyzeOrTerm(). It is not helpful 
-  ** with virtual tables.
-  **
   ** Note that bitmasks are created for all pTabList->nSrc tables in
   ** pTabList, not just the first nTabList tables.  nTabList is normally
   ** equal to pTabList->nSrc but might be shortened to 1 if the
   ** WHERE_ONETABLE_ONLY flag is set.
   */
-  assert( sWBI.pWC->vmask==0 && pMaskSet->n==0 );
   for(ii=0; ii<pTabList->nSrc; ii++){
     createMask(pMaskSet, pTabList->a[ii].iCursor);
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    if( ALWAYS(pTabList->a[ii].pTab) && IsVirtual(pTabList->a[ii].pTab) ){
-      sWBI.pWC->vmask |= ((Bitmask)1 << ii);
-    }
-#endif
   }
 #ifndef NDEBUG
   {
@@ -5031,6 +5219,7 @@ WhereInfo *sqlite3WhereBegin(
     int bestJ = -1;             /* The value of j */
     Bitmask m;                  /* Bitmask value for j or bestJ */
     int isOptimal;              /* Iterator for optimal/non-optimal search */
+    int ckOptimal;              /* Do the optimal scan check */
     int nUnconstrained;         /* Number tables without INDEXED BY */
     Bitmask notIndexed;         /* Mask of tables that cannot use an index */
 
@@ -5065,10 +5254,8 @@ WhereInfo *sqlite3WhereBegin(
     ** strategies were found by the first iteration. This second iteration
     ** is used to search for the lowest cost scan overall.
     **
-    ** Previous versions of SQLite performed only the second iteration -
-    ** the next outermost loop was always that with the lowest overall
-    ** cost. However, this meant that SQLite could select the wrong plan
-    ** for scripts such as the following:
+    ** Without the optimal scan step (the first iteration) a suboptimal
+    ** plan might be chosen for queries like this:
     **   
     **   CREATE TABLE t1(a, b); 
     **   CREATE TABLE t2(c, d);
@@ -5083,17 +5270,41 @@ WhereInfo *sqlite3WhereBegin(
     */
     nUnconstrained = 0;
     notIndexed = 0;
-    for(isOptimal=(iFrom<nTabList-1); isOptimal>=0 && bestJ<0; isOptimal--){
+
+    /* The optimal scan check only occurs if there are two or more tables
+    ** available to be reordered */
+    if( iFrom==nTabList-1 ){
+      ckOptimal = 0;  /* Common case of just one table in the FROM clause */
+    }else{
+      ckOptimal = -1;
       for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){
-        int doNotReorder;    /* True if this table should not be reordered */
-  
-        doNotReorder =  (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0;
-        if( j!=iFrom && doNotReorder ) break;
         m = getMask(pMaskSet, sWBI.pSrc->iCursor);
         if( (m & sWBI.notValid)==0 ){
           if( j==iFrom ) iFrom++;
           continue;
         }
+        if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ) break;
+        if( ++ckOptimal ) break;
+        if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break;
+      }
+    }
+    assert( ckOptimal==0 || ckOptimal==1 );
+
+    for(isOptimal=ckOptimal; isOptimal>=0 && bestJ<0; isOptimal--){
+      for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){
+        if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ){
+          /* This break and one like it in the ckOptimal computation loop
+          ** above prevent table reordering across LEFT and CROSS JOINs.
+          ** The LEFT JOIN case is necessary for correctness.  The prohibition
+          ** against reordering across a CROSS JOIN is an SQLite feature that
+          ** allows the developer to control table reordering */
+          break;
+        }
+        m = getMask(pMaskSet, sWBI.pSrc->iCursor);
+        if( (m & sWBI.notValid)==0 ){
+          assert( j>iFrom );
+          continue;
+        }
         sWBI.notReady = (isOptimal ? m : sWBI.notValid);
         if( sWBI.pSrc->pIndex==0 ) nUnconstrained++;
   
@@ -5122,8 +5333,8 @@ WhereInfo *sqlite3WhereBegin(
         }
         if( isOptimal ){
           pWInfo->a[j].rOptCost = sWBI.cost.rCost;
-        }else if( iFrom<nTabList-1 ){
-          /* If two or more tables have nearly the same outer loop cost,
+        }else if( ckOptimal ){
+          /* If two or more tables have nearly the same outer loop cost, but
           ** very different inner loop (optimal) cost, we want to choose
           ** for the outer loop that table which benefits the least from
           ** being in the inner loop.  The following code scales the 
@@ -5168,11 +5379,19 @@ WhereInfo *sqlite3WhereBegin(
           bestPlan = sWBI.cost;
           bestJ = j;
         }
-        if( doNotReorder ) break;
+
+        /* In a join like "w JOIN x LEFT JOIN y JOIN z"  make sure that
+        ** table y (and not table z) is always the next inner loop inside
+        ** of table x. */
+        if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break;
       }
     }
     assert( bestJ>=0 );
     assert( sWBI.notValid & getMask(pMaskSet, pTabList->a[bestJ].iCursor) );
+    assert( bestJ==iFrom || (pTabList->a[iFrom].jointype & JT_LEFT)==0 );
+    testcase( bestJ>iFrom && (pTabList->a[iFrom].jointype & JT_CROSS)!=0 );
+    testcase( bestJ>iFrom && bestJ<nTabList-1
+                          && (pTabList->a[bestJ+1].jointype & JT_LEFT)!=0 );
     WHERETRACE(("*** Optimizer selects table %d (%s) for loop %d with:\n"
                 "    cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=0x%08x\n",
                 bestJ, pTabList->a[bestJ].pTab->zName,
@@ -5424,7 +5643,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
       sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
       for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
         sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
-        sqlite3VdbeAddOp2(v, OP_Next, pIn->iCur, pIn->addrInTop);
+        sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
         sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
       }
       sqlite3DbFree(db, pLevel->u.in.aInLoop);
diff --git a/lib/libsqlite3/tool/build-shell.sh b/lib/libsqlite3/tool/build-shell.sh
index 8e62a71746c..6a48299d73b 100644
--- a/lib/libsqlite3/tool/build-shell.sh
+++ b/lib/libsqlite3/tool/build-shell.sh
@@ -17,5 +17,6 @@ gcc -o sqlite3 -g -Os -I. \
    -DSQLITE_ENABLE_RTREE \
    -DHAVE_READLINE \
    -DHAVE_USLEEP=1 \
-   ../sqlite/src/shell.c ../sqlite/src/test_vfstrace.c \
+   ../sqlite/src/shell.c \
+   ../sqlite/src/test_vfstrace.c \
    sqlite3.c -ldl -lreadline -lncurses
diff --git a/lib/libsqlite3/tool/mksqlite3c.tcl b/lib/libsqlite3/tool/mksqlite3c.tcl
index 2c569d7a4eb..c93bcea44d5 100644
--- a/lib/libsqlite3/tool/mksqlite3c.tcl
+++ b/lib/libsqlite3/tool/mksqlite3c.tcl
@@ -23,7 +23,7 @@
 #
 
 # Begin by reading the "sqlite3.h" header file.  Extract the version number
-# from in this file.  The versioon number is needed to generate the header
+# from in this file.  The version number is needed to generate the header
 # comment of the amalgamation.
 #
 if {[lsearch $argv --nostatic]>=0} {
@@ -311,6 +311,7 @@ foreach file {
    fts3_porter.c
    fts3_tokenizer.c
    fts3_tokenizer1.c
+   fts3_tokenize_vtab.c
    fts3_write.c
    fts3_snippet.c
    fts3_unicode.c
diff --git a/lib/libsqlite3/tool/mksqlite3h.tcl b/lib/libsqlite3/tool/mksqlite3h.tcl
index f68f61a3689..a89b9f9beb0 100644
--- a/lib/libsqlite3/tool/mksqlite3h.tcl
+++ b/lib/libsqlite3/tool/mksqlite3h.tcl
@@ -68,9 +68,14 @@ set declpattern {^ *[a-zA-Z][a-zA-Z_0-9 ]+ \**sqlite3_[_a-zA-Z0-9]+\(}
 # Force the output to use unix line endings, even on Windows.
 fconfigure stdout -translation lf
 
-# Process the src/sqlite.h.in ext/rtree/sqlite3rtree.h files.
+set filelist [subst {
+  $TOP/src/sqlite.h.in
+  $TOP/ext/rtree/sqlite3rtree.h
+}]
+
+# Process the source files.
 #
-foreach file [list $TOP/src/sqlite.h.in $TOP/ext/rtree/sqlite3rtree.h] {
+foreach file $filelist {
   set in [open $file]
   while {![eof $in]} {
   
diff --git a/lib/libsqlite3/tool/showdb.c b/lib/libsqlite3/tool/showdb.c
index a100bba4f50..27424e09201 100644
--- a/lib/libsqlite3/tool/showdb.c
+++ b/lib/libsqlite3/tool/showdb.c
@@ -176,7 +176,7 @@ static void print_db_header(void){
   print_decode_line(aData, 56, 4, "Text encoding");
   print_decode_line(aData, 60, 4, "User version");
   print_decode_line(aData, 64, 4, "Incremental-vacuum mode");
-  print_decode_line(aData, 68, 4, "meta[7]");
+  print_decode_line(aData, 68, 4, "Application ID");
   print_decode_line(aData, 72, 4, "meta[8]");
   print_decode_line(aData, 76, 4, "meta[9]");
   print_decode_line(aData, 80, 4, "meta[10]");
@@ -471,7 +471,7 @@ static void page_usage_msg(int pgno, const char *zFormat, ...){
   zMsg = sqlite3_vmprintf(zFormat, ap);
   va_end(ap);
   if( pgno<=0 || pgno>mxPage ){
-    printf("ERROR: page %d out of bounds.  Range=1..%d.  Msg: %s\n",
+    printf("ERROR: page %d out of range 1..%d: %s\n",
             pgno, mxPage, zMsg);
     sqlite3_free(zMsg);
     return;
@@ -479,7 +479,7 @@ static void page_usage_msg(int pgno, const char *zFormat, ...){
   if( zPageUse[pgno]!=0 ){
     printf("ERROR: page %d used multiple times:\n", pgno);
     printf("ERROR:    previous: %s\n", zPageUse[pgno]);
-    printf("ERROR:    current:  %s\n", zPageUse[pgno]);
+    printf("ERROR:    current:  %s\n", zMsg);
     sqlite3_free(zPageUse[pgno]);
   }
   zPageUse[pgno] = zMsg;
@@ -616,14 +616,31 @@ static void page_usage_freelist(int pgno){
 }
 
 /*
+** Determine pages used as PTRMAP pages
+*/
+static void page_usage_ptrmap(unsigned char *a){
+  if( a[55] ){
+    int usable = pagesize - a[20];
+    int pgno = 2;
+    int perPage = usable/5;
+    while( pgno<=mxPage ){
+      page_usage_msg(pgno, "PTRMAP page covering %d..%d",
+                           pgno+1, pgno+perPage);
+      pgno += perPage + 1;
+    }
+  }
+}
+
+/*
 ** Try to figure out how every page in the database file is being used.
 */
 static void page_usage_report(const char *zDbName){
-  int i;
+  int i, j;
   int rc;
   sqlite3 *db;
   sqlite3_stmt *pStmt;
   unsigned char *a;
+  char zQuery[200];
 
   /* Avoid the pathological case */
   if( mxPage<1 ){
@@ -648,20 +665,26 @@ static void page_usage_report(const char *zDbName){
   /* Discover the usage of each page */
   a = getContent(0, 100);
   page_usage_freelist(decodeInt32(a+32));
+  page_usage_ptrmap(a);
   free(a);
   page_usage_btree(1, 0, 0, "sqlite_master");
-  rc = sqlite3_prepare_v2(db,
-           "SELECT type, name, rootpage FROM SQLITE_MASTER WHERE rootpage",
-           -1, &pStmt, 0);
-  if( rc==SQLITE_OK ){
-    while( sqlite3_step(pStmt)==SQLITE_ROW ){
-      int pgno = sqlite3_column_int(pStmt, 2);
-      page_usage_btree(pgno, 0, 0, sqlite3_column_text(pStmt, 1));
+  sqlite3_exec(db, "PRAGMA writable_schema=ON", 0, 0, 0);
+  for(j=0; j<2; j++){
+    sqlite3_snprintf(sizeof(zQuery), zQuery,
+             "SELECT type, name, rootpage FROM SQLITE_MASTER WHERE rootpage"
+             " ORDER BY rowid %s", j?"DESC":"");
+    rc = sqlite3_prepare_v2(db, zQuery, -1, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      while( sqlite3_step(pStmt)==SQLITE_ROW ){
+        int pgno = sqlite3_column_int(pStmt, 2);
+        page_usage_btree(pgno, 0, 0, sqlite3_column_text(pStmt, 1));
+      }
+    }else{
+      printf("ERROR: cannot query database: %s\n", sqlite3_errmsg(db));
     }
-  }else{
-    printf("ERROR: cannot query database: %s\n", sqlite3_errmsg(db));
+    rc = sqlite3_finalize(pStmt);
+    if( rc==SQLITE_OK ) break;
   }
-  sqlite3_finalize(pStmt);
   sqlite3_close(db);
 
   /* Print the report and free memory used */
@@ -674,6 +697,53 @@ static void page_usage_report(const char *zDbName){
 }
 
 /*
+** Try to figure out how every page in the database file is being used.
+*/
+static void ptrmap_coverage_report(const char *zDbName){
+  unsigned int pgno;
+  unsigned char *aHdr;
+  unsigned char *a;
+  int usable;
+  int perPage;
+  unsigned int i;
+
+  /* Avoid the pathological case */
+  if( mxPage<1 ){
+    printf("empty database\n");
+    return;
+  }
+
+  /* Make sure PTRMAPs are used in this database */
+  aHdr = getContent(0, 100);
+  if( aHdr[55]==0 ){
+    printf("database does not use PTRMAP pages\n");
+    return;
+  }
+  usable = pagesize - aHdr[20];
+  perPage = usable/5;
+  free(aHdr);
+  printf("%5d: root of sqlite_master\n", 1);
+  for(pgno=2; pgno<=mxPage; pgno += perPage+1){
+    printf("%5d: PTRMAP page covering %d..%d\n", pgno,
+           pgno+1, pgno+perPage);
+    a = getContent((pgno-1)*pagesize, usable);
+    for(i=0; i+5<=usable && pgno+1+i/5<=mxPage; i+=5){
+      const char *zType = "???";
+      unsigned int iFrom = decodeInt32(&a[i+1]);
+      switch( a[i] ){
+        case 1:  zType = "b-tree root page";        break;
+        case 2:  zType = "freelist page";           break;
+        case 3:  zType = "first page of overflow";  break;
+        case 4:  zType = "later page of overflow";  break;
+        case 5:  zType = "b-tree non-root page";    break;
+      }
+      printf("%5d: %s, parent=%u\n", pgno+1+i/5, zType, iFrom);
+    }
+    free(a);
+  }
+}
+
+/*
 ** Print a usage comment
 */
 static void usage(const char *argv0){
@@ -682,6 +752,7 @@ static void usage(const char *argv0){
     "args:\n"
     "    dbheader        Show database header\n"
     "    pgidx           Index of how each page is used\n"
+    "    ptrmap          Show all PTRMAP page content\n"
     "    NNN..MMM        Show hex of pages NNN through MMM\n"
     "    NNN..end        Show hex of pages NNN through end of file\n"
     "    NNNb            Decode btree page NNN\n"
@@ -731,6 +802,14 @@ int main(int argc, char **argv){
         page_usage_report(argv[1]);
         continue;
       }
+      if( strcmp(argv[i], "ptrmap")==0 ){
+        ptrmap_coverage_report(argv[1]);
+        continue;
+      }
+      if( strcmp(argv[i], "help")==0 ){
+        usage(argv[0]);
+        continue;
+      }
       if( !isdigit(argv[i][0]) ){
         fprintf(stderr, "%s: unknown option: [%s]\n", argv[0], argv[i]);
         continue;
diff --git a/lib/libsqlite3/tool/showwal.c b/lib/libsqlite3/tool/showwal.c
index ae25a59f9a2..2888c10aa59 100644
--- a/lib/libsqlite3/tool/showwal.c
+++ b/lib/libsqlite3/tool/showwal.c
@@ -18,6 +18,65 @@ static int perLine = 16;        /* HEX elements to print per line */
 
 typedef long long int i64;      /* Datatype for 64-bit integers */
 
+/* Information for computing the checksum */
+typedef struct Cksum Cksum;
+struct Cksum {
+  int bSwap;           /* True to do byte swapping on 32-bit words */
+  unsigned s0, s1;     /* Current checksum value */
+};
+
+/*
+** extract a 32-bit big-endian integer
+*/
+static unsigned int getInt32(const unsigned char *a){
+  unsigned int x = (a[0]<<24) + (a[1]<<16) + (a[2]<<8) + a[3];
+  return x;
+}
+
+/*
+** Swap bytes on a 32-bit unsigned integer
+*/
+static unsigned int swab32(unsigned int x){
+  return (((x)&0x000000FF)<<24) + (((x)&0x0000FF00)<<8)
+         + (((x)&0x00FF0000)>>8)  + (((x)&0xFF000000)>>24);
+}
+
+/* Extend the checksum.  Reinitialize the checksum if bInit is true.
+*/
+static void extendCksum(
+  Cksum *pCksum,
+  unsigned char *aData,
+  unsigned int nByte,
+  int bInit
+){
+  unsigned int *a32;
+  if( bInit ){
+    int a = 0;
+    *((char*)&a) = 1;
+    if( a==1 ){
+      /* Host is little-endian */
+      pCksum->bSwap = getInt32(aData)!=0x377f0682;
+    }else{
+      /* Host is big-endian */
+      pCksum->bSwap = getInt32(aData)!=0x377f0683;
+    }
+    pCksum->s0 = 0;
+    pCksum->s1 = 0;
+  }
+  a32 = (unsigned int*)aData;
+  while( nByte>0 ){
+    unsigned int x0 = a32[0];
+    unsigned int x1 = a32[1];
+    if( pCksum->bSwap ){
+      x0 = swab32(x0);
+      x1 = swab32(x1);
+    }
+    pCksum->s0 += x0 + pCksum->s1;
+    pCksum->s1 += x1 + pCksum->s0;
+    nByte -= 8;
+    a32 += 2;
+  }
+}
 
 /*
 ** Convert the var-int format into i64.  Return the number of bytes
@@ -152,39 +211,46 @@ static void print_frame(int iFrame){
 }
 
 /*
-** extract a 32-bit big-endian integer
-*/
-static unsigned int getInt32(const unsigned char *a){
-  unsigned int x = (a[0]<<24) + (a[1]<<16) + (a[2]<<8) + a[3];
-  return x;
-}
-
-/*
-** Print an entire page of content as hex
+** Summarize a single frame on a single line.
 */
-static void print_oneline_frame(int iFrame){
+static void print_oneline_frame(int iFrame, Cksum *pCksum){
   int iStart;
   unsigned char *aData;
+  unsigned int s0, s1;
   iStart = 32 + (iFrame-1)*(pagesize+24);
   aData = getContent(iStart, 24);
-  fprintf(stdout, "Frame %4d: %6d %6d 0x%08x 0x%08x 0x%08x 0x%08x\n",
+  extendCksum(pCksum, aData, 8, 0);
+  extendCksum(pCksum, getContent(iStart+24, pagesize), pagesize, 0);
+  s0 = getInt32(aData+16);
+  s1 = getInt32(aData+20);
+  fprintf(stdout, "Frame %4d: %6d %6d 0x%08x,%08x 0x%08x,%08x %s\n",
           iFrame, 
           getInt32(aData),
           getInt32(aData+4),
           getInt32(aData+8),
           getInt32(aData+12),
-          getInt32(aData+16),
-          getInt32(aData+20)
+          s0,
+          s1,
+          (s0==pCksum->s0 && s1==pCksum->s1) ? "" : "cksum-fail"
   );
+
+  /* Reset the checksum so that a single frame checksum failure will not
+  ** cause all subsequent frames to also show a failure. */
+  pCksum->s0 = s0;
+  pCksum->s1 = s1;
   free(aData);
 }
 
 /*
 ** Decode the WAL header.
 */
-static void print_wal_header(void){
+static void print_wal_header(Cksum *pCksum){
   unsigned char *aData;
   aData = getContent(0, 32);
+  if( pCksum ){
+    extendCksum(pCksum, aData, 24, 1);
+    printf("Checksum byte order: %s\n", pCksum->bSwap ? "swapped" : "native");
+  }
   printf("WAL Header:\n");
   print_decode_line(aData, 0, 4,1,"Magic.  0x377f0682 (le) or 0x377f0683 (be)");
   print_decode_line(aData, 4, 4, 0, "File format");
@@ -194,60 +260,199 @@ static void print_wal_header(void){
   print_decode_line(aData, 20,4, 1, "Salt-2");
   print_decode_line(aData, 24,4, 1, "Checksum-1");
   print_decode_line(aData, 28,4, 1, "Checksum-2");
+  if( pCksum ){
+    if( pCksum->s0!=getInt32(aData+24) ){
+      printf("**** cksum-1 mismatch: 0x%08x\n", pCksum->s0);
+    }
+    if( pCksum->s1!=getInt32(aData+28) ){
+      printf("**** cksum-2 mismatch: 0x%08x\n", pCksum->s1);
+    }
+  }
   free(aData);
 }
+/*
+** Describe cell content.
+*/
+static int describeContent(
+  unsigned char *a,       /* Cell content */
+  int nLocal,             /* Bytes in a[] */
+  char *zDesc             /* Write description here */
+){
+  int nDesc = 0;
+  int n, i, j;
+  i64 x, v;
+  const unsigned char *pData;
+  const unsigned char *pLimit;
+  char sep = ' ';
+
+  pLimit = &a[nLocal];
+  n = decodeVarint(a, &x);
+  pData = &a[x];
+  a += n;
+  i = x - n;
+  while( i>0 && pData<=pLimit ){
+    n = decodeVarint(a, &x);
+    a += n;
+    i -= n;
+    nLocal -= n;
+    zDesc[0] = sep;
+    sep = ',';
+    nDesc++;
+    zDesc++;
+    if( x==0 ){
+      sprintf(zDesc, "*");     /* NULL is a "*" */
+    }else if( x>=1 && x<=6 ){
+      v = (signed char)pData[0];
+      pData++;
+      switch( x ){
+        case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
+        case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
+        case 4:  v = (v<<8) + pData[0];  pData++;
+        case 3:  v = (v<<8) + pData[0];  pData++;
+        case 2:  v = (v<<8) + pData[0];  pData++;
+      }
+      sprintf(zDesc, "%lld", v);
+    }else if( x==7 ){
+      sprintf(zDesc, "real");
+      pData += 8;
+    }else if( x==8 ){
+      sprintf(zDesc, "0");
+    }else if( x==9 ){
+      sprintf(zDesc, "1");
+    }else if( x>=12 ){
+      int size = (x-12)/2;
+      if( (x&1)==0 ){
+        sprintf(zDesc, "blob(%d)", size);
+      }else{
+        sprintf(zDesc, "txt(%d)", size);
+      }
+      pData += size;
+    }
+    j = strlen(zDesc);
+    zDesc += j;
+    nDesc += j;
+  }
+  return nDesc;
+}
+
+/*
+** Compute the local payload size given the total payload size and
+** the page size.
+*/
+static int localPayload(i64 nPayload, char cType){
+  int maxLocal;
+  int minLocal;
+  int surplus;
+  int nLocal;
+  if( cType==13 ){
+    /* Table leaf */
+    maxLocal = pagesize-35;
+    minLocal = (pagesize-12)*32/255-23;
+  }else{
+    maxLocal = (pagesize-12)*64/255-23;
+    minLocal = (pagesize-12)*32/255-23;
+  }
+  if( nPayload>maxLocal ){
+    surplus = minLocal + (nPayload-minLocal)%(pagesize-4);
+    if( surplus<=maxLocal ){
+      nLocal = surplus;
+    }else{
+      nLocal = minLocal;
+    }
+  }else{
+    nLocal = nPayload;
+  }
+  return nLocal;
+}
 
 /*
 ** Create a description for a single cell.
+**
+** The return value is the local cell size.
 */
-static int describeCell(unsigned char cType, unsigned char *a, char **pzDesc){
+static int describeCell(
+  unsigned char cType,    /* Page type */
+  unsigned char *a,       /* Cell content */
+  int showCellContent,    /* Show cell content if true */
+  char **pzDesc           /* Store description here */
+){
   int i;
   int nDesc = 0;
   int n = 0;
   int leftChild;
   i64 nPayload;
   i64 rowid;
-  static char zDesc[100];
+  int nLocal;
+  static char zDesc[1000];
   i = 0;
   if( cType<=5 ){
     leftChild = ((a[0]*256 + a[1])*256 + a[2])*256 + a[3];
     a += 4;
     n += 4;
-    sprintf(zDesc, "left-child: %d ", leftChild);
+    sprintf(zDesc, "lx: %d ", leftChild);
     nDesc = strlen(zDesc);
   }
   if( cType!=5 ){
     i = decodeVarint(a, &nPayload);
     a += i;
     n += i;
-    sprintf(&zDesc[nDesc], "sz: %lld ", nPayload);
+    sprintf(&zDesc[nDesc], "n: %lld ", nPayload);
     nDesc += strlen(&zDesc[nDesc]);
+    nLocal = localPayload(nPayload, cType);
+  }else{
+    nPayload = nLocal = 0;
   }
   if( cType==5 || cType==13 ){
     i = decodeVarint(a, &rowid);
     a += i;
     n += i;
-    sprintf(&zDesc[nDesc], "rowid: %lld ", rowid);
+    sprintf(&zDesc[nDesc], "r: %lld ", rowid);
     nDesc += strlen(&zDesc[nDesc]);
   }
+  if( nLocal<nPayload ){
+    int ovfl;
+    unsigned char *b = &a[nLocal];
+    ovfl = ((b[0]*256 + b[1])*256 + b[2])*256 + b[3];
+    sprintf(&zDesc[nDesc], "ov: %d ", ovfl);
+    nDesc += strlen(&zDesc[nDesc]);
+    n += 4;
+  }
+  if( showCellContent && cType!=5 ){
+    nDesc += describeContent(a, nLocal, &zDesc[nDesc-1]);
+  }
   *pzDesc = zDesc;
-  return n;
+  return nLocal+n;
 }
 
 /*
 ** Decode a btree page
 */
-static void decode_btree_page(unsigned char *a, int pgno, int hdrSize){
+static void decode_btree_page(
+  unsigned char *a,   /* Content of the btree page to be decoded */
+  int pgno,           /* Page number */
+  int hdrSize,        /* Size of the page1-header in bytes */
+  const char *zArgs   /* Flags to control formatting */
+){
   const char *zType = "unknown";
   int nCell;
-  int i;
+  int i, j;
   int iCellPtr;
+  int showCellContent = 0;
+  int showMap = 0;
+  char *zMap = 0;
   switch( a[0] ){
     case 2:  zType = "index interior node";  break;
     case 5:  zType = "table interior node";  break;
     case 10: zType = "index leaf";           break;
     case 13: zType = "table leaf";           break;
   }
+  while( zArgs[0] ){
+    switch( zArgs[0] ){
+      case 'c': showCellContent = 1;  break;
+      case 'm': showMap = 1;          break;
+    }
+    zArgs++;
+  }
   printf("Decode of btree page %d:\n", pgno);
   print_decode_line(a, 0, 1, 0, zType);
   print_decode_line(a, 1, 2, 0, "Offset to first freeblock");
@@ -261,13 +466,40 @@ static void decode_btree_page(unsigned char *a, int pgno, int hdrSize){
   }else{
     iCellPtr = 8;
   }
+  if( nCell>0 ){
+    printf(" key: lx=left-child n=payload-size r=rowid\n");
+  }
+  if( showMap ){
+    zMap = malloc(pagesize);
+    memset(zMap, '.', pagesize);
+    memset(zMap, '1', hdrSize);
+    memset(&zMap[hdrSize], 'H', iCellPtr);
+    memset(&zMap[hdrSize+iCellPtr], 'P', 2*nCell);
+  }
   for(i=0; i<nCell; i++){
     int cofst = iCellPtr + i*2;
     char *zDesc;
+    int n;
+
     cofst = a[cofst]*256 + a[cofst+1];
-    describeCell(a[0], &a[cofst-hdrSize], &zDesc);
+    n = describeCell(a[0], &a[cofst-hdrSize], showCellContent, &zDesc);
+    if( showMap ){
+      char zBuf[30];
+      memset(&zMap[cofst], '*', n);
+      zMap[cofst] = '[';
+      zMap[cofst+n-1] = ']';
+      sprintf(zBuf, "%d", i);
+      j = strlen(zBuf);
+      if( j<=n-2 ) memcpy(&zMap[cofst+1], zBuf, j);
+    }
     printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
   }
+  if( showMap ){
+    for(i=0; i<pagesize; i+=64){
+      printf(" %03x: %.64s\n", i, &zMap[i]);
+    }
+    free(zMap);
+  }  
 }
 
 int main(int argc, char **argv){
@@ -298,15 +530,18 @@ int main(int argc, char **argv){
   printf("Available pages: 1..%d\n", mxFrame);
   if( argc==2 ){
     int i;
-    print_wal_header();
-    for(i=1; i<=mxFrame; i++) print_oneline_frame(i);
+    Cksum x;
+    print_wal_header(&x);
+    for(i=1; i<=mxFrame; i++){
+      print_oneline_frame(i, &x);
+    }
   }else{
     int i;
     for(i=2; i<argc; i++){
       int iStart, iEnd;
       char *zLeft;
       if( strcmp(argv[i], "header")==0 ){
-        print_wal_header();
+        print_wal_header(0);
         continue;
       }
       if( !isdigit(argv[i][0]) ){
@@ -318,11 +553,11 @@ int main(int argc, char **argv){
         iEnd = mxFrame;
       }else if( zLeft && zLeft[0]=='.' && zLeft[1]=='.' ){
         iEnd = strtol(&zLeft[2], 0, 0);
-#if 0
       }else if( zLeft && zLeft[0]=='b' ){
         int ofst, nByte, hdrSize;
         unsigned char *a;
         if( iStart==1 ){
+          hdrSize = 100;
           ofst = hdrSize = 100;
           nByte = pagesize-100;
         }else{
@@ -330,11 +565,11 @@ int main(int argc, char **argv){
           ofst = (iStart-1)*pagesize;
           nByte = pagesize;
         }
+        ofst = 32 + hdrSize + (iStart-1)*(pagesize+24) + 24;
         a = getContent(ofst, nByte);
-        decode_btree_page(a, iStart, hdrSize);
+        decode_btree_page(a, iStart, hdrSize, zLeft+1);
         free(a);
         continue;
-#endif
       }else{
         iEnd = iStart;
       }