From: René Scharfe <l.s.r@web.de>
Date: Sun, 16 Jul 2017 11:16:01 +0000 (+0200)
Subject: ls-files: don't try to prune an empty index
X-Git-Tag: v2.14.2~54^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=168e63554cbd965fee4d0092e02f8170eba7481f;p=thirdparty%2Fgit.git

ls-files: don't try to prune an empty index

Exit early when asked to prune an index that contains no entries to
begin with.  This avoids pointer arithmetic on istate->cache, which is
possibly NULL in that case.

Found with Clang's UBSan.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index dc4a6aa3d9..c6126eae55 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -362,7 +362,7 @@ static void prune_index(struct index_state *istate,
 	int pos;
 	unsigned int first, last;
 
-	if (!prefix)
+	if (!prefix || !istate->cache_nr)
 		return;
 	pos = index_name_pos(istate, prefix, prefixlen);
 	if (pos < 0)