=== modified file 'storage/innobase/row/row0mysql.cc'
--- storage/innobase/row/row0mysql.cc	2013-03-26 13:01:45 +0000
+++ storage/innobase/row/row0mysql.cc	2013-06-01 23:18:32 +0000
@@ -5422,6 +5422,7 @@
 				    dtuple_get_nth_field(prev_entry, i))) {
 
 				contains_null = TRUE;
+				break;
 			}
 		}