[FFmpeg-cvslog] av_memcpy_backptr: avoid an infinite loop for back = 0

[Anton Khirnov]

ffmpeg | branch: release/1.1 | Anton Khirnov <anton at khirnov.net> | Wed Feb 13 21:36:25 2013 +0100| [48fd461977f77f02668111769865e3740908e82a] | committer: Reinhard Tartler

av_memcpy_backptr: avoid an infinite loop for back = 0

CC:libav-stable at libav.org
(cherry picked from commit f935aca44c674d30e3ed940ef73bbad1228a5855)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=48fd461977f77f02668111769865e3740908e82a
---

 libavutil/mem.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavutil/mem.c b/libavutil/mem.c
index 3a4433d..391eb7d 100644
--- a/libavutil/mem.c
+++ b/libavutil/mem.c
@@ -252,6 +252,9 @@ static void fill32(uint8_t *dst, int len)
 void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
 {
     const uint8_t *src = &dst[-back];
+    if (!back)
+        return;
+
     if (back == 1) {
         memset(dst, *src, cnt);
     } else if (back == 2) {