ERROR Plugin 'MEMORY' has ref_count=1 after shutdown for SJM queries.

SET optimizer_switch = 'materialization=on,semijoin=on';

CREATE TABLE t1 (pk INT, a INT, b INT, PRIMARY KEY(pk)) ENGINE=MyISAM;

INSERT INTO t1 VALUES (1,3,5),(2,4,6);

SELECT * FROM t1 WHERE 8 IN (SELECT MIN(pk) FROM t1) AND (pk = a OR pk = b);

DROP TABLE t1;

130912 10:35:46 [Warning] Plugin 'MEMORY' will be forced to shutdown

130912 10:35:46 [ERROR] Plugin 'MEMORY' has ref_count=1 after shutdown.