Bug #16521 Events: mysql.event.on_completion value is 'DROP'

Description:
I create an event using the clause ON COMPLETION NOT PRESERVE.
In mysql.event, the on_completion value for this event says
"DROP" instead of "NOT PRESERVE".

How to repeat:
mysql> create event e_63 on schedule every 1 second on completion not preserve do set @a=5;
Query OK, 1 row affected (0.00 sec)

mysql> select on_completion from mysql.event where name = 'e_63';
+---------------+
| on_completion |
+---------------+
| DROP          |
+---------------+
1 row in set (0.00 sec)

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mysql> create event e_63 on schedule every 1 second on completion not preserve
    -> do set @a=5;
Query OK, 1 row affected (0.03 sec)

mysql> select on_completion from mysql.event where name = 'e_63';
+---------------+
| on_completion |
+---------------+
| DROP          |
+---------------+
1 row in set (0.01 sec)

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/1276

I don't think it's a bug - nowhere in the manual we promise that the content of the mysql.* tables will match exactly what you've typed. E.g. you write GRANT ... TO user@host but there's no '@' character in mysql.user table.