CREATE TABLE t1 (id int(11) NOT NULL PRIMARY KEY, name varchar(20),
INDEX (name)) ENGINE=InnoDB;
CREATE TABLE t2 (id int(11) NOT NULL PRIMARY KEY, fkey int(11),
FOREIGN KEY (fkey) REFERENCES t2(id)) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1,'A1'),(2,'A2'),(3,'B');
INSERT INTO t2 VALUES (1,1),(2,2),(3,2),(4,3),(5,3);
ANALYZE TABLE t1;
ANALYZE TABLE t2;
EXPLAIN
SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON t2.fkey = t1.id 
WHERE t1.name LIKE 'A%';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	PRIMARY,name	name	23	NULL	3	Using where; Using index
1	SIMPLE	t2	ref	fkey	fkey	5	test.t1.id	1	Using index
EXPLAIN
SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON t2.fkey = t1.id 
WHERE t1.name LIKE 'A%' OR FALSE;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	fkey	5	NULL	5	Using index
1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.fkey	1	Using where
DROP TABLE t1,t2;
#
# BUG#58456: Assertion 0 in QUICK_INDEX_MERGE_SELECT::need_sorted_output
#            in opt_range.h
#
CREATE TABLE t1 (
col_int INT,
col_int_key INT,
pk INT NOT NULL,
PRIMARY KEY (pk),
KEY col_int_key (col_int_key)
) ENGINE=InnoDB;
INSERT INTO t1 VALUES (NULL,1,1), (6,2,2), (5,3,3), (NULL,4,4);
INSERT INTO t1 VALUES (1,NULL,6), (8,5,7), (NULL,8,8), (8,NULL,5);
ANALYZE TABLE t1;
CREATE TABLE t2 (
pk INT PRIMARY KEY
) ENGINE=InnoDB;

EXPLAIN SELECT t1.pk
FROM t2 LEFT JOIN t1 ON t2.pk = t1.col_int
WHERE t1.col_int_key BETWEEN 5 AND 6 
AND t1.pk IS NULL OR t1.pk IN (5)
ORDER BY pk;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	const	PRIMARY,col_int_key	PRIMARY	4	const	2	Using where
1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.col_int	1	Using index

SELECT t1.pk
FROM t2 LEFT JOIN t1 ON t2.pk = t1.col_int
WHERE t1.col_int_key BETWEEN 5 AND 6 
AND t1.pk IS NULL OR t1.pk IN (5)
ORDER BY pk;
pk

DROP TABLE t1,t2;
# End BUG#58456