Unexpected Results by join_cache_bka

CREATE TABLE t0(c0 CHAR(100));

CREATE TABLE t1(c0 CHAR(100) UNIQUE);

SET SESSION join_cache_level = 7;

REPAIR TABLE t1, t0 QUICK EXTENDED;

INSERT INTO t0 VALUES ('%S');

INSERT INTO t1 VALUES ('');

INSERT INTO t1 VALUES ('*');

INSERT INTO t0 VALUES ('');

INSERT INTO t1 VALUES ('\r');

SELECT t0.c0 FROM t0 NATURAL JOIN t1 WHERE TRUE RLIKE t1.c0; -- {}

SET STATEMENT optimizer_switch = 'join_cache_bka=off' FOR SELECT t0.c0 FROM t0 NATURAL JOIN t1 WHERE TRUE RLIKE t1.c0; -- empty