[FFmpeg-cvslog] avformat/mpc8: fix broken pointer math

[wm4]

ffmpeg | branch: release/1.2 | wm4 <nfxjfg at googlemail.com> | Tue Feb  3 19:04:11 2015 +0100| [49dd89f9027f3def12e170bb7d986d37812eedba] | committer: Michael Niedermayer

avformat/mpc8: fix broken pointer math

This could overflow and crash at least on 32 bit systems.

Reviewed-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit b737a2c52857b214be246ff615c6293730033cfa)

Conflicts:

	libavformat/mpc8.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=49dd89f9027f3def12e170bb7d986d37812eedba
---

 libavformat/mpc8.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c
index 916639f..56db807 100644
--- a/libavformat/mpc8.c
+++ b/libavformat/mpc8.c
@@ -91,7 +91,7 @@ static int mpc8_probe(AVProbeData *p)
         size = bs_get_v(&bs);
         if (size < 2)
             return 0;
-        if (bs + size - 2 >= bs_end)
+        if (size >= bs_end - bs + 2)
             return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
         if (header_found) {
             if (size < 11 || size > 28)