=== modified file 'sql/item_subselect.cc'
--- sql/item_subselect.cc	2013-02-26 12:08:54 +0000
+++ sql/item_subselect.cc	2013-05-03 14:46:59 +0000
@@ -1491,8 +1491,10 @@
   for (SELECT_LEX* lex= select_lex->master_unit()->first_select();
        lex != NULL && lex->master_unit() == select_lex->master_unit();
        lex= lex->next_select())
-    if (lex->item_list.head()->maybe_null)
+    if (lex->item_list.head()->maybe_null) {
       subquery_maybe_null= true;
+      break;
+    }
 
   /*
     If this is an ALL/ANY single-value subquery predicate, try to rewrite