A metadata lock never dies

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is 8

Server version: 5.5.30-MariaDB mariadb.org binary distribution

Copyright (c) 2000, 2013, Oracle, Monty Program Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> DELIMITER ||

MariaDB [(none)]> DROP FUNCTION IF EXISTS `test`.`f`;

    -> CREATE FUNCTION `test`.`f`() RETURNS TINYINT UNSIGNED

    -> BEGIN

    ->  RETURN 1;

    -> END;

    -> ||

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.24 sec)

MariaDB [(none)]>

MariaDB [test]> SELECT test.f();

+----------+

| test.f() |

+----------+

|        1 |

+----------+

1 row in set (0.00 sec)

MariaDB [test]>

MariaDB [(none)]> DROP FUNCTION IF EXISTS `test`.`f`;

    -> ||

MariaDB [test]> SHOW FULL PROCESSLIST;

+----+------+----------------+------+---------+------+-------------------------------------------+------------------------------------+----------+

| Id | User | Host           | db   | Command | Time | State                 | Info                               | Progress |

+----+------+----------------+------+---------+------+-------------------------------------------+------------------------------------+----------+

|  6 | root | localhost:3504 | test | Query   |    0 | NULL                 | SHOW FULL PROCESSLIST              |    0.000 |

|  8 | root | localhost:3508 | NULL | Query   |  594 | Waiting for stored function metadata lock | DROP FUNCTION IF EXISTS `test`.`f` |    0.000 |

+----+------+----------------+------+---------+------+-------------------------------------------+------------------------------------+----------+

2 rows in set (0.00 sec)

MariaDB [test]>