Make sed's -i flag more compatible with what gsed does.

- Reset the hold-space in between files
- quit the editor as soon as a 'q' command is found
- Make sure the temp-file is written back to the original file if we quit
  the editor

temp-file not written back issue found by Time Chase.
Lots of feedback from millert@ and schwarze@
OK millert@

4 files changed, 42 insertions, 28 deletions

diff --git a/usr.bin/sed/extern.h b/usr.bin/sed/extern.h
index 77ed8ef1c5d..772f0bab3ef 100644
--- a/usr.bin/sed/extern.h
+++ b/usr.bin/sed/extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: extern.h,v 1.13 2017/08/01 18:05:53 martijn Exp $ */
+/*	$OpenBSD: extern.h,v 1.14 2018/11/14 10:59:33 martijn Exp $ */
 /*-
  * Copyright (c) 1992 Diomidis Spinellis.
  * Copyright (c) 1992, 1993
@@ -53,8 +53,9 @@ __dead void error(int, const char *, ...);
 void	warning(const char *, ...);
 int	 mf_fgets(SPACE *, enum e_spflag);
 int	 lastline(void);
+void	 finish_file(void);
 void	 process(void);
-void	 resetranges(void);
+void	 resetstate(void);
 char	*strregerror(int, regex_t *);
 void	*xmalloc(size_t);
 void	*xreallocarray(void *, size_t, size_t);
diff --git a/usr.bin/sed/main.c b/usr.bin/sed/main.c
index 2ef2ec1013f..60535638cd4 100644
--- a/usr.bin/sed/main.c
+++ b/usr.bin/sed/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.37 2018/07/11 06:57:18 martijn Exp $	*/
+/*	$OpenBSD: main.c,v 1.38 2018/11/14 10:59:33 martijn Exp $	*/
 
 /*-
  * Copyright (c) 1992 Diomidis Spinellis.
@@ -310,6 +310,30 @@ again:
 	return (NULL);
 }
 
+void
+finish_file(void)
+{
+	if (infile != NULL) {
+		fclose(infile);
+		if (*oldfname != '\0') {
+			if (rename(fname, oldfname) != 0) {
+				warning("rename()");
+				unlink(tmpfname);
+				exit(1);
+			}
+			*oldfname = '\0';
+		}
+		if (*tmpfname != '\0') {
+			if (outfile != NULL && outfile != stdout)
+				fclose(outfile);
+			outfile = NULL;
+			rename(tmpfname, fname);
+			*tmpfname = '\0';
+		}
+		outfname = NULL;
+	}
+}
+
 /*
  * Like fgets, but go through the list of files chaining them together.
  * Set len to the length of the line.
@@ -347,25 +371,7 @@ mf_fgets(SPACE *sp, enum e_spflag spflag)
 			sp->len = 0;
 			return (0);
 		}
-		if (infile != NULL) {
-			fclose(infile);
-			if (*oldfname != '\0') {
-				if (rename(fname, oldfname) != 0) {
-					warning("rename()");
-					unlink(tmpfname);
-					exit(1);
-				}
-				*oldfname = '\0';
-			}
-			if (*tmpfname != '\0') {
-				if (outfile != NULL && outfile != stdout)
-					fclose(outfile);
-				outfile = NULL;
-				rename(tmpfname, fname);
-				*tmpfname = '\0';
-			}
-			outfname = NULL;
-		}
+		finish_file();
 		if (firstfile == 0)
 			files = files->next;
 		else
@@ -405,7 +411,7 @@ mf_fgets(SPACE *sp, enum e_spflag spflag)
 			fchmod(fileno(outfile), sb.st_mode & ALLPERMS);
 			outfname = tmpfname;
 			linenum = 0;
-			resetranges();
+			resetstate();
 		} else {
 			outfile = stdout;
 			outfname = "stdout";
diff --git a/usr.bin/sed/process.c b/usr.bin/sed/process.c
index 654cf758ab8..cc31fcb57a3 100644
--- a/usr.bin/sed/process.c
+++ b/usr.bin/sed/process.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: process.c,v 1.33 2017/12/13 16:06:34 millert Exp $	*/
+/*	$OpenBSD: process.c,v 1.34 2018/11/14 10:59:33 martijn Exp $	*/
 
 /*-
  * Copyright (c) 1992 Diomidis Spinellis.
@@ -196,6 +196,7 @@ redirect:
 				if (!nflag && !pd)
 					OUT();
 				flush_appends();
+				finish_file();
 				exit(0);
 			case 'r':
 				if (appendx >= appendnum) {
@@ -312,10 +313,13 @@ applies(struct s_command *cp)
  * Reset all inrange markers.
  */
 void
-resetranges(void)
+resetstate(void)
 {
 	struct s_command *cp;
 
+	free(HS.back);
+	memset(&HS, 0, sizeof(HS));
+
 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
 		if (cp->a2)
 			cp->inrange = 0;
diff --git a/usr.bin/sed/sed.1 b/usr.bin/sed/sed.1
index af3a4cdea08..226735865e7 100644
--- a/usr.bin/sed/sed.1
+++ b/usr.bin/sed/sed.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: sed.1,v 1.56 2018/07/11 06:47:38 martijn Exp $
+.\"	$OpenBSD: sed.1,v 1.57 2018/11/14 10:59:33 martijn Exp $
 .\"
 .\" Copyright (c) 1992, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -32,7 +32,7 @@
 .\"
 .\"	from: @(#)sed.1	8.2 (Berkeley) 12/30/93
 .\"
-.Dd $Mdocdate: July 11 2018 $
+.Dd $Mdocdate: November 14 2018 $
 .Dt SED 1
 .Os
 .Sh NAME
@@ -106,6 +106,9 @@ It is not recommended to give a zero length
 .Ar extension
 when in place editing files, as it risks corruption or partial content
 in situations where disk space is exhausted, etc.
+In
+.Fl i
+mode, the hold space, line numbers, and ranges are reset between files.
 .It Fl r
 An alias for
 .Fl E ,
@@ -392,7 +395,7 @@ Write the pattern space to standard output.
 Write the pattern space, up to the first newline character,
 to the standard output.
 .It [1addr] Ns Ic q
-Branch to the end of the script and quit without starting a new cycle.
+Branch to the end of the script and quit without starting a new cycle or file.
 .It [1addr] Ns Ic r Ar file
 Copy the contents of
 .Ar file