Test bug 942377.

t/pt-upgrade/samples/006/tables.sql

@@ -0,0 +1,12 @@
+DROP DATABASE IF EXISTS test;
+CREATE DATABASE test;
+USE test;
+CREATE TABLE t (
+  id    int(10) NOT NULL AUTO_INCREMENT,
+  city  varchar(8) default NULL,
+  PRIMARY KEY  (`id`)
+);
+INSERT INTO t VALUES
+  (null,  'aaa'),
+  (null,  'bbb'),
+  (null,  'ccc');