[FFmpeg-cvslog] avcodec/pngdsp: fix (un)signed type in end comparission

[Michael Niedermayer]

ffmpeg | branch: release/1.2 | Michael Niedermayer <michaelni at gmx.at> | Fri Aug 30 23:14:32 2013 +0200| [ddce97c7b0e460bafa0e7da72b6c4b8193f23cda] | committer: Carl Eugen Hoyos

avcodec/pngdsp: fix (un)signed type in end comparission

Fixes out of array accesses
Fixes Ticket2919

Found_by: ami_stuff
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit 86736f59d6a527d8bc807d09b93f971c0fe0bb07)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ddce97c7b0e460bafa0e7da72b6c4b8193f23cda
---

 libavcodec/pngdsp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/pngdsp.c b/libavcodec/pngdsp.c
index 1ee8b57..38ee458 100644
--- a/libavcodec/pngdsp.c
+++ b/libavcodec/pngdsp.c
@@ -30,7 +30,7 @@
 static void add_bytes_l2_c(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w)
 {
     long i;
-    for (i = 0; i <= w - sizeof(long); i += sizeof(long)) {
+    for (i = 0; i <= w - (int)sizeof(long); i += sizeof(long)) {
         long a = *(long *)(src1 + i);
         long b = *(long *)(src2 + i);
         *(long *)(dst + i) = ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80);