[FFmpeg-cvslog] avformat/matroskadec: fix off by 1 error in matroska_read_seek()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Fri May 30 05:21:24 2014 +0200| [b3dfebd6416058d5b849317a7d96b3d9085943fd] | committer: Michael Niedermayer

avformat/matroskadec: fix off by 1 error in matroska_read_seek()

Fixes out of array read

Fixes: vp9-opus-crash.webm

Found-by: Dale Curtis <dalecurtis at google.com>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b3dfebd6416058d5b849317a7d96b3d9085943fd
---

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

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 65847fa..213767c 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -3018,7 +3018,7 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
                 tracks[i].stream, st->index_entries[index].timestamp,
                 AVSEEK_FLAG_BACKWARD);
             while (index_sub >= 0 &&
-                  index_min >= 0 &&
+                  index_min > 0 &&
                   tracks[i].stream->index_entries[index_sub].pos < st->index_entries[index_min].pos &&
                   st->index_entries[index].timestamp - tracks[i].stream->index_entries[index_sub].timestamp < 30000000000 / matroska->time_scale)
                 index_min--;