From 60f7eec450c6174dafb47ccd96b247293dbc75c9 Mon Sep 17 00:00:00 2001
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Fri, 29 Oct 2010 19:34:57 +0000
Subject: [PATCH] sh: Fix some issues with CTL* bytes and ${var#pat}.

subevalvar() incorrectly assumed that CTLESC bytes were present iff the
expansion was quoted. However, they are present iff various processing such
as word splitting is to be done later on.

Example:
  v=@$e@$e@$e@
  y="${v##*"$e"}"
  echo "$y"
failed if $e contained the magic CTLESC byte.

Exp-run done by:	pav (with some other sh(1) changes)
---
 bin/sh/expand.c                           | 27 +++++++++++------------
 tools/regression/bin/sh/expansion/trim6.0 | 22 ++++++++++++++++++
 2 files changed, 35 insertions(+), 14 deletions(-)
 create mode 100644 tools/regression/bin/sh/expansion/trim6.0

diff --git a/bin/sh/expand.c b/bin/sh/expand.c
index 13dc38a9a16b..200da3f046d4 100644
--- a/bin/sh/expand.c
+++ b/bin/sh/expand.c
@@ -98,7 +98,7 @@ static struct arglist exparg;		/* holds expanded arg list */
 static void argstr(char *, int);
 static char *exptilde(char *, int);
 static void expbackq(union node *, int, int);
-static int subevalvar(char *, char *, int, int, int, int);
+static int subevalvar(char *, char *, int, int, int, int, int);
 static char *evalvar(char *, int);
 static int varisset(char *, int);
 static void varvalue(char *, int, int, int);
@@ -526,7 +526,7 @@ expbackq(union node *cmd, int quoted, int flag)
 
 static int
 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
-  int varflags)
+  int varflags, int quotes)
 {
 	char *startp;
 	char *loc = NULL;
@@ -571,12 +571,12 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 		for (loc = startp; loc < str; loc++) {
 			c = *loc;
 			*loc = '\0';
-			if (patmatch(str, startp, varflags & VSQUOTE)) {
+			if (patmatch(str, startp, quotes)) {
 				*loc = c;
 				goto recordleft;
 			}
 			*loc = c;
-			if ((varflags & VSQUOTE) && *loc == CTLESC)
+			if (quotes && *loc == CTLESC)
 				loc++;
 		}
 		return 0;
@@ -585,14 +585,13 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 		for (loc = str - 1; loc >= startp;) {
 			c = *loc;
 			*loc = '\0';
-			if (patmatch(str, startp, varflags & VSQUOTE)) {
+			if (patmatch(str, startp, quotes)) {
 				*loc = c;
 				goto recordleft;
 			}
 			*loc = c;
 			loc--;
-			if ((varflags & VSQUOTE) && loc > startp &&
-			    *(loc - 1) == CTLESC) {
+			if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 				for (q = startp; q < loc; q++)
 					if (*q == CTLESC)
 						q++;
@@ -604,14 +603,13 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 
 	case VSTRIMRIGHT:
 		for (loc = str - 1; loc >= startp;) {
-			if (patmatch(str, loc, varflags & VSQUOTE)) {
+			if (patmatch(str, loc, quotes)) {
 				amount = loc - expdest;
 				STADJUST(amount, expdest);
 				return 1;
 			}
 			loc--;
-			if ((varflags & VSQUOTE) && loc > startp &&
-			    *(loc - 1) == CTLESC) {
+			if (quotes && loc > startp && *(loc - 1) == CTLESC) {
 				for (q = startp; q < loc; q++)
 					if (*q == CTLESC)
 						q++;
@@ -623,12 +621,12 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 
 	case VSTRIMRIGHTMAX:
 		for (loc = startp; loc < str - 1; loc++) {
-			if (patmatch(str, loc, varflags & VSQUOTE)) {
+			if (patmatch(str, loc, quotes)) {
 				amount = loc - expdest;
 				STADJUST(amount, expdest);
 				return 1;
 			}
-			if ((varflags & VSQUOTE) && *loc == CTLESC)
+			if (quotes && *loc == CTLESC)
 				loc++;
 		}
 		return 0;
@@ -779,7 +777,7 @@ evalvar(char *p, int flag)
 		STPUTC('\0', expdest);
 		patloc = expdest - stackblock();
 		if (subevalvar(p, NULL, patloc, subtype,
-			       startloc, varflags) == 0) {
+		    startloc, varflags, quotes) == 0) {
 			int amount = (expdest - stackblock() - patloc) + 1;
 			STADJUST(-amount, expdest);
 		}
@@ -790,7 +788,8 @@ evalvar(char *p, int flag)
 	case VSASSIGN:
 	case VSQUESTION:
 		if (!set) {
-			if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
+			if (subevalvar(p, var, 0, subtype, startloc, varflags,
+			    quotes)) {
 				varflags &= ~VSNUL;
 				/*
 				 * Remove any recorded regions beyond
diff --git a/tools/regression/bin/sh/expansion/trim6.0 b/tools/regression/bin/sh/expansion/trim6.0
new file mode 100644
index 000000000000..3f753c4113f6
--- /dev/null
+++ b/tools/regression/bin/sh/expansion/trim6.0
@@ -0,0 +1,22 @@
+# $FreeBSD$
+
+e=
+for i in 0 1 2 3; do
+	for j in 0 1 2 3 4 5 6 7; do
+		for k in 0 1 2 3 4 5 6 7; do
+			case $i$j$k in
+			000) continue ;;
+			esac
+			e="$e\\$i$j$k"
+		done
+	done
+done
+e=$(printf "$e")
+v=@$e@$e@
+y=${v##*"$e"}
+yq="${v##*"$e"}"
+[ "$y" = @ ] || echo "error when unquoted in non-splitting context"
+[ "$yq" = @ ] || echo "error when quoted in non-splitting context"
+[ "${v##*"$e"}" = @ ] || echo "error when quoted in splitting context"
+IFS=
+[ ${v##*"$e"} = @ ] || echo "error when unquoted in splitting context"