Index: main/astobj2.c
===================================================================
--- main/astobj2.c	(revision 252276)
+++ main/astobj2.c	(working copy)
@@ -262,6 +262,9 @@
 	int current_value;
 	int ret;
 
+	if (obj == NULL)
+		return -1;
+
 	/* if delta is 0, just return the refcount */
 	if (delta == 0)
 		return (obj->priv_data.ref_counter);
@@ -499,7 +502,7 @@
 	struct bucket_list *p;
 	struct astobj2 *obj = INTERNAL_OBJ(user_data);
 
-	if (!obj)
+	if (obj == NULL)
 		return NULL;
 
 	if (INTERNAL_OBJ(c) == NULL)