[FFmpeg-cvslog] matroskadec: fix NULL pointer dereference

[Andreas Cadhalpun]

ffmpeg | branch: master | Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com> | Sun Oct 16 21:47:00 2016 +0200| [eb751f06db9f627c8b5c63d08836a39f7572bf56] | committer: Andreas Cadhalpun

matroskadec: fix NULL pointer dereference

The problem was introduced in commit 1273bc6.

Reviewed-by: James Almer <jamrial at gmail.com>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=eb751f06db9f627c8b5c63d08836a39f7572bf56
---

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

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 8847c62..a5d3c0e 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1759,7 +1759,7 @@ static int mkv_field_order(MatroskaDemuxContext *matroska, int64_t field_order)
 
     /* workaround a bug in our Matroska muxer, introduced in version 57.36 alongside
      * this function, and fixed in 57.52 */
-    if (sscanf(matroska->muxingapp, "Lavf%d.%d.%d", &major, &minor, &micro) == 3)
+    if (matroska->muxingapp && sscanf(matroska->muxingapp, "Lavf%d.%d.%d", &major, &minor, &micro) == 3)
         bttb = (major == 57 && minor >= 36 && minor <= 51 && micro >= 100);
 
     switch (field_order) {