merge changes becuase of the fix for bug 22367

WHERE t2.fk < 'c' AND t2.pk=t1.fk;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	range	PRIMARY	PRIMARY	12	NULL	3	Using where

1	SIMPLE	t2	ref	PRIMARY	PRIMARY	18	test.t1.fk	1	Using where

1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	18	test.t1.fk	1	Using where

EXPLAIN SELECT t2.* 

FROM t1 JOIN t2 ON t2.fk=t1.pk 

WHERE t2.fk BETWEEN 'a' AND 'b' AND t2.pk=t1.fk;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	range	PRIMARY	PRIMARY	12	NULL	2	Using where

1	SIMPLE	t2	ref	PRIMARY	PRIMARY	18	test.t1.fk	1	Using where

1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	18	test.t1.fk	1	Using where

EXPLAIN SELECT t2.* 

FROM t1 JOIN t2 ON t2.fk=t1.pk 

WHERE t2.fk IN ('a','b') AND t2.pk=t1.fk;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	range	PRIMARY	PRIMARY	12	NULL	2	Using where

1	SIMPLE	t2	ref	PRIMARY	PRIMARY	18	test.t1.fk	1	Using where

1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	18	test.t1.fk	1	Using where

DROP TABLE t1,t2;

CREATE TABLE t1 (a int, b varchar(20) NOT NULL, PRIMARY KEY(a));

CREATE TABLE t2 (a int, b varchar(20) NOT NULL,