Intermittent ExeMgr crash for a query involving foreign table UPDATE

ret=0; i=0; while [ $ret -eq 0 ]; do echo $i; mariadb test < exemgr_crash.sql > exemgr_crash.sql.log; ret=$?; ((i=i+1)); done

DROP TABLE IF EXISTS cstab1;

DROP TABLE IF EXISTS innotab1;

CREATE TABLE cstab1 (

  a int(11) DEFAULT NULL,

  b varchar(10) DEFAULT NULL

) ENGINE=Columnstore;

INSERT INTO cstab1 VALUES (1,'cs01');

INSERT INTO cstab1 VALUES (2,'cs02');

CREATE TABLE innotab1 (

  a int(11) DEFAULT NULL,

  b varchar(10) DEFAULT NULL

) ENGINE=InnoDB;

INSERT INTO innotab1 VALUES (1,'in01');

SELECT * FROM cstab1;

SELECT * FROM innotab1;

SELECT '--- Updating ---' AS ``;

UPDATE innotab1 SET a=100 WHERE a IN (SELECT a FROM cstab1 WHERE a=1);

SELECT * FROM cstab1;

SELECT * FROM innotab1;

DROP TABLE cstab1;

DROP TABLE innotab1;