From ef0cb80dd456b8f0feaf8d176d0aae89c1d3de18 Mon Sep 17 00:00:00 2001
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Sat, 5 Feb 2011 14:01:46 +0000
Subject: [PATCH] sh: Forget all cached command locations on any PATH change.

POSIX requires this and it is simpler than the previous code that remembered
command locations when appending directories to PATH.

In particular,
  PATH=$PATH
is no longer a no-op but discards all cached command locations.
---
 bin/sh/exec.c                             | 25 +----------------------
 tools/regression/bin/sh/execution/hash1.0 | 12 +++++++++++
 2 files changed, 13 insertions(+), 24 deletions(-)
 create mode 100644 tools/regression/bin/sh/execution/hash1.0

diff --git a/bin/sh/exec.c b/bin/sh/exec.c
index 6297e9b4b07f..67eafffe32cc 100644
--- a/bin/sh/exec.c
+++ b/bin/sh/exec.c
@@ -494,30 +494,7 @@ hashcd(void)
 void
 changepath(const char *newval)
 {
-	const char *old, *new;
-	int idx;
-	int firstchange;
-
-	old = pathval();
-	new = newval;
-	firstchange = 9999;	/* assume no change */
-	idx = 0;
-	for (;;) {
-		if (*old != *new) {
-			firstchange = idx;
-			if ((*old == '\0' && *new == ':')
-			 || (*old == ':' && *new == '\0'))
-				firstchange++;
-			old = new;	/* ignore subsequent differences */
-		}
-		if (*new == '\0')
-			break;
-		if (*new == ':') {
-			idx++;
-		}
-		new++, old++;
-	}
-	clearcmdentry(firstchange);
+	clearcmdentry(0);
 }
 
 
diff --git a/tools/regression/bin/sh/execution/hash1.0 b/tools/regression/bin/sh/execution/hash1.0
new file mode 100644
index 000000000000..a645c2aef735
--- /dev/null
+++ b/tools/regression/bin/sh/execution/hash1.0
@@ -0,0 +1,12 @@
+# $FreeBSD$
+
+T=`mktemp -d "${TMPDIR:-/tmp}/sh-test.XXXXXXXX"` || exit
+trap 'rm -rf "${T}"' 0
+PATH=$T:$PATH
+ls -ld . >/dev/null
+cat <<EOF >"$T/ls"
+:
+EOF
+chmod 755 "$T/ls"
+PATH=$PATH
+ls -ld .