Bug #17564 RENAME DATABASE doesn't change user privileges

Description:
If you rename a database with the new RENAME DATABASE command, the privileges remain unchanged.

How to repeat:
mysql> create user user@localhost;
Query OK, 0 rows affected (0.00 sec)

mysql> grant all on test2.* to user@localhost;
Query OK, 0 rows affected (0.00 sec)

mysql> rename database test2 to test;
Query OK, 0 rows affected (0.01 sec)

mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select Host, User, Db from db;
+-----------+------+-------+
| Host      | User | Db    |
+-----------+------+-------+
| localhost | user | test2 |
+-----------+------+-------+
1 row in set (0.00 sec)

mysql>

Suggested fix:
RENAME DATABASE should also change the database information in the privilege tables.

The reported behavior is as documented:

http://dev.mysql.com/doc/refman/5.1/en/rename-database.html

Analogously, RENAME TABLE changes no privileges, either.

Expected behavior how Paul commented it.