From: Thomas Rast <trast@student.ethz.ch>
Date: Sun, 17 Oct 2010 19:23:21 +0000 (+0200)
Subject: prefix_filename(): safely handle the case where pfx_len=0
X-Git-Tag: v1.7.3.3~8^2~1
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=9e5f5d4cfea5bb7706f1f8bb07795d52d37a59fe;p=git.git

prefix_filename(): safely handle the case where pfx_len=0

Current prefix_filename() is proofed against the case where the prefix
'pfx' is NULL or a 0-length string, _except on Windows_.

Change the behaviour to work the same on both platforms, and only
check pfx_len so that callers passing a NULL prefix with a nonzero
pfx_len segfault early on both.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/setup.c b/setup.c
index a3b76de2b..346ef2eb2 100644
--- a/setup.c
+++ b/setup.c
@@ -46,7 +46,7 @@ const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
 {
 	static char path[PATH_MAX];
 #ifndef WIN32
-	if (!pfx || !*pfx || is_absolute_path(arg))
+	if (!pfx_len || is_absolute_path(arg))
 		return arg;
 	memcpy(path, pfx, pfx_len);
 	strcpy(path + pfx_len, arg);
@@ -55,7 +55,7 @@ const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
 	/* don't add prefix to absolute paths, but still replace '\' by '/' */
 	if (is_absolute_path(arg))
 		pfx_len = 0;
-	else
+	else if (pfx_len)
 		memcpy(path, pfx, pfx_len);
 	strcpy(path + pfx_len, arg);
 	for (p = path + pfx_len; *p; p++)