--- a/src/lib/png.c	Mon Jan 25 04:14:03 2010 +0200
+++ b/src/lib/png.c	Mon Jan 25 04:29:25 2010 +0200
@@ -502,8 +502,7 @@
     int err;
 
     // init img
-    img->png = NULL;
-    img->info = NULL;
+    memset(img, 0, sizeof(*img));
 
     // check within bounds
     if (ti->x >= header->width || ti->y >= header->height)