Circular foreign keys cause a loop and OOM upon LOCK TABLE

--source include/have_innodb.inc

SET FOREIGN_KEY_CHECKS=0;

DROP SCHEMA IF EXISTS sakila;

CREATE SCHEMA sakila;

USE sakila;

CREATE TABLE staff (

  staff_id TINYINT UNSIGNED NOT NULL AUTO_INCREMENT,

  store_id TINYINT UNSIGNED NOT NULL,

  PRIMARY KEY  (staff_id),

  KEY idx_fk_store_id (store_id),

  CONSTRAINT fk_staff_store FOREIGN KEY (store_id) REFERENCES store (store_id) ON DELETE RESTRICT ON UPDATE CASCADE

)ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE store (

  store_id TINYINT UNSIGNED NOT NULL AUTO_INCREMENT,

  manager_staff_id TINYINT UNSIGNED NOT NULL,

  PRIMARY KEY  (store_id),

  UNIQUE KEY idx_unique_manager (manager_staff_id),

  CONSTRAINT fk_store_staff FOREIGN KEY (manager_staff_id) REFERENCES staff (staff_id) ON DELETE RESTRICT ON UPDATE CASCADE

)ENGINE=InnoDB DEFAULT CHARSET=utf8;

SET FOREIGN_KEY_CHECKS=DEFAULT;

LOCK TABLE staff WRITE;

# Cleanup

UNLOCK TABLES;

DROP SCHEMA sakila;

25261 elenst    20   0 3165920 1.846g  17312 S  97.6 11.8   0:02.31 mysqld

25261 elenst    20   0 6180576 4.703g  17312 S  99.1 30.2   0:05.29 mysqld

25261 elenst    20   0 9195232 7.570g  17312 S  99.1 48.5   0:08.27 mysqld

...