meta engine: add checks to verify that we indeed have the inputitem and it's dir when we use it.

modules/meta_engine/folder.c

@@ -73,9 +73,14 @@ static int FindMeta( vlc_object_t *p_this )
     int i = 0;
     struct stat a;
     char psz_filename[MAX_PATH];
+    if( !p_item )
+        return VLC_EGENERIC;
+
     char *psz_dir = input_item_GetURI( p_item );
-    char *psz_buf = strrchr( psz_dir, '/' );
+    if( !psz_dir )
+        return VLC_EGENERIC;
 
+    char *psz_buf = strrchr( psz_dir, '/' );
     if( psz_buf )
     {
         psz_buf++;