[SCM] libav/experimental: Check for invalid motion vector, fixes issue 2521.

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit 43c34675afee8ced294ecc436f58587e8e8e913b
Author: Daniel Kang <daniel.d.kang at gmail.com>
Date:   Mon Jan 10 10:28:06 2011 +0000

    Check for invalid motion vector, fixes issue 2521.
    
    Patch by Daniel Kang, daniel.d.kang at gmail
    
    Originally committed as revision 26293 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/roqvideo.c b/libavcodec/roqvideo.c
index 830eb7b..eb8fc25 100644
--- a/libavcodec/roqvideo.c
+++ b/libavcodec/roqvideo.c
@@ -115,6 +115,11 @@ static inline void apply_motion_generic(RoqContext *ri, int x, int y, int deltax
         return;
     }
 
+    if (ri->last_frame->data[0] == NULL) {
+        av_log(ri->avctx, AV_LOG_ERROR, "Invalid decode type. Invalid header?\n");
+        return;
+    }
+
     for(cp = 0; cp < 3; cp++) {
         int outstride = ri->current_frame->linesize[cp];
         int instride  = ri->last_frame   ->linesize[cp];

-- 
Libav/FFmpeg packaging