Print an error if a reference picture is missing.

Originally committed as revision 14403 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -3007,8 +3007,10 @@ static int decode_ref_pic_list_reordering(H264Context *h){
     }
     for(list=0; list<h->list_count; list++){
         for(index= 0; index < h->ref_count[list]; index++){
-            if(!h->ref_list[list][index].data[0])
+            if(!h->ref_list[list][index].data[0]){
-                h->ref_list[list][index]= s->current_picture;
+                av_log(h->s.avctx, AV_LOG_ERROR, "Missing reference picture\n");
+                h->ref_list[list][index]= s->current_picture; //FIXME this is not a sensible solution
+            }
         }
     }