Do not read past the end of the buffer if an "f" layout font modifier

is followed by the end of the input line instead of a font specifier.
Found by jsg@ with afl, test case #591.

While here, improve functionality as well:
* There is no "r" font modifier.
* Font specifiers (as opposed to font modifiers) are case sensitive.
* One-character font specifiers require trailing whitespace.
* Ignore parenthised and two-letter font specifiers.

8 files changed, 72 insertions, 19 deletions

diff --git a/regress/usr.bin/mandoc/tbl/mod/Makefile b/regress/usr.bin/mandoc/tbl/mod/Makefile
index 9c1bdb98484..c5bebb0ff5f 100644
--- a/regress/usr.bin/mandoc/tbl/mod/Makefile
+++ b/regress/usr.bin/mandoc/tbl/mod/Makefile
@@ -1,13 +1,15 @@
-# $OpenBSD: Makefile,v 1.1.1.1 2015/01/29 23:24:24 schwarze Exp $
+# $OpenBSD: Makefile,v 1.2 2015/02/10 11:02:19 schwarze Exp $
 
-REGRESS_TARGETS	 = expand font misalign
+REGRESS_TARGETS	 = badfont expand font misalign
+LINT_TARGETS	 = badfont font
 
-# groff-1.22.3 defect:
+# groff-1.22.3 defects:
+# - The "f" font modifier swallows a following newline character.
 # - When space is insufficient (on either side) for properly aligning
 #   a number, GNU tbl(1) moves the number too much to the right,
 #   overflowing the column, even if space would be sufficient without
 #   left padding.
 
-SKIP_GROFF	 = misalign
+SKIP_GROFF	 = badfont misalign
 
 .include <bsd.regress.mk>
diff --git a/regress/usr.bin/mandoc/tbl/mod/badfont.in b/regress/usr.bin/mandoc/tbl/mod/badfont.in
new file mode 100644
index 00000000000..4b765aef08c
--- /dev/null
+++ b/regress/usr.bin/mandoc/tbl/mod/badfont.in
@@ -0,0 +1,14 @@
+.TH TBL-MOD-BADFONT 1 "February 10, 2015" OpenBSD
+.SH NAME
+tbl-mod-badfont \- invalid font modifiers in table layouts
+.SH DESCRIPTION
+normal text
+.TS
+box tab(:);
+lfB lf
+lfI lf.
+lfB lfI.
+bold:none
+italic:none
+bold:italic
+.TE
diff --git a/regress/usr.bin/mandoc/tbl/mod/badfont.out_ascii b/regress/usr.bin/mandoc/tbl/mod/badfont.out_ascii
new file mode 100644
index 00000000000..b0788c5040a
--- /dev/null
+++ b/regress/usr.bin/mandoc/tbl/mod/badfont.out_ascii
@@ -0,0 +1,18 @@
+TBL-MOD-BADFONT(1)          General Commands Manual         TBL-MOD-BADFONT(1)
+
+
+
+NNAAMMEE
+       tbl-mod-badfont - invalid font modifiers in table layouts
+
+DDEESSCCRRIIPPTTIIOONN
+       normal text
+
+       +----------------+
+       |bboolldd     none   |
+       |_i_t_a_l_i_c   none   |
+       |bboolldd     _i_t_a_l_i_c |
+       +----------------+
+
+
+OpenBSD                        February 10, 2015            TBL-MOD-BADFONT(1)
diff --git a/regress/usr.bin/mandoc/tbl/mod/badfont.out_lint b/regress/usr.bin/mandoc/tbl/mod/badfont.out_lint
new file mode 100644
index 00000000000..0882648cd46
--- /dev/null
+++ b/regress/usr.bin/mandoc/tbl/mod/badfont.out_lint
@@ -0,0 +1,2 @@
+mandoc: badfont.in:8:7: WARNING: unknown font, skipping request: TS f
+mandoc: badfont.in:9:7: WARNING: unknown font, skipping request: TS f.
diff --git a/regress/usr.bin/mandoc/tbl/mod/font.in b/regress/usr.bin/mandoc/tbl/mod/font.in
index caf73e85688..b371bfcb3cc 100644
--- a/regress/usr.bin/mandoc/tbl/mod/font.in
+++ b/regress/usr.bin/mandoc/tbl/mod/font.in
@@ -1,12 +1,12 @@
-.TH TBL-MOD-FONT 1 2014-10-14 OpenBSD
+.TH TBL-MOD-FONT 1 "February 10, 2015" OpenBSD
 .SH NAME
 tbl-mod-font \- font modifiers in table layouts
 .SH DESCRIPTION
 normal text
 .TS
 box tab(:);
-cb | c | ci
-cFI | c | cFB .
+cb|cfCW|ci
+cFI | cf(foobar) | cFB.
 bold:roman:italic
 _
 italic:roman:bold
diff --git a/regress/usr.bin/mandoc/tbl/mod/font.out_ascii b/regress/usr.bin/mandoc/tbl/mod/font.out_ascii
index 18845607172..70438643820 100644
--- a/regress/usr.bin/mandoc/tbl/mod/font.out_ascii
+++ b/regress/usr.bin/mandoc/tbl/mod/font.out_ascii
@@ -16,4 +16,4 @@ DDEESSCCRRIIPPTTIIOONN
        +-------+-------+--------+
 
 
-OpenBSD                           2014-10-14                   TBL-MOD-FONT(1)
+OpenBSD                        February 10, 2015               TBL-MOD-FONT(1)
diff --git a/regress/usr.bin/mandoc/tbl/mod/font.out_lint b/regress/usr.bin/mandoc/tbl/mod/font.out_lint
new file mode 100644
index 00000000000..14506a511d9
--- /dev/null
+++ b/regress/usr.bin/mandoc/tbl/mod/font.out_lint
@@ -0,0 +1 @@
+mandoc: font.in:8:6: WARNING: unknown font, skipping request: TS fCW|ci
diff --git a/usr.bin/mandoc/tbl_layout.c b/usr.bin/mandoc/tbl_layout.c
index f50d3aeb365..7e4655479d0 100644
--- a/usr.bin/mandoc/tbl_layout.c
+++ b/usr.bin/mandoc/tbl_layout.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tbl_layout.c,v 1.24 2015/01/30 04:08:37 schwarze Exp $ */
+/*	$OpenBSD: tbl_layout.c,v 1.25 2015/02/10 11:02:19 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -95,12 +95,8 @@ mod:
 
 	switch (tolower((unsigned char)p[(*pos)++])) {
 	case 'b':
-		/* FALLTHROUGH */
-	case 'i':
-		/* FALLTHROUGH */
-	case 'r':
-		(*pos)--;
-		break;
+		cp->flags |= TBL_CELL_BOLD;
+		goto mod;
 	case 'd':
 		cp->flags |= TBL_CELL_BALIGN;
 		goto mod;
@@ -109,6 +105,9 @@ mod:
 		goto mod;
 	case 'f':
 		break;
+	case 'i':
+		cp->flags |= TBL_CELL_ITALIC;
+		goto mod;
 	case 'm':
 		mandoc_msg(MANDOCERR_TBLLAYOUT_MOD, tbl->parse,
 		    ln, *pos, "m");
@@ -148,20 +147,37 @@ mod:
 		goto mod;
 	}
 
-	switch (tolower((unsigned char)p[(*pos)++])) {
+	/* Ignore parenthised font names for now. */
+
+	if (p[*pos] == '(')
+		goto mod;
+
+	/* Support only one-character font-names for now. */
+
+	if (p[*pos] == '\0' || (p[*pos + 1] != ' ' && p[*pos + 1] != '.')) {
+		mandoc_vmsg(MANDOCERR_FT_BAD, tbl->parse,
+		    ln, *pos, "TS %s", p + *pos - 1);
+		if (p[*pos] != '\0')
+			(*pos)++;
+		if (p[*pos] != '\0')
+			(*pos)++;
+		goto mod;
+	}
+
+	switch (p[(*pos)++]) {
 	case '3':
 		/* FALLTHROUGH */
-	case 'b':
+	case 'B':
 		cp->flags |= TBL_CELL_BOLD;
 		goto mod;
 	case '2':
 		/* FALLTHROUGH */
-	case 'i':
+	case 'I':
 		cp->flags |= TBL_CELL_ITALIC;
 		goto mod;
 	case '1':
 		/* FALLTHROUGH */
-	case 'r':
+	case 'R':
 		goto mod;
 	default:
 		mandoc_vmsg(MANDOCERR_FT_BAD, tbl->parse,