av_memcpy_backptr: avoid an infinite loop for back = 0

CC:libav-stable@libav.org
12 years ago · f935aca44c
parent 8097fc9a2d
commit f935aca44c
1 changed files with 3 additions and 0 deletions
--- 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) {