Fix possible segfault

Commited in SoC by Bobby Bingham on 2007-07-14 23:16:15


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@12689 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavfilter/avfiltergraph.c

@@ -112,7 +112,8 @@ int avfilter_graph_load_chain(AVFilterGraph *graph,
 
 fail:
     destroy_graph_filters(graph);
-    *first = *last = NULL;
+    if(first) *first = NULL;
+    if(last)  *last  = NULL;
     return -1;
 }