MDEV-7149 Constant propagation erroneously applied for LIKE

Simply disallowing equality propagation into LIKE.
A more delicate fix is be possible, but it would need too many changes,
which is not desirable in 10.0 at this point.

mysql-test/include/ctype_like_cond_propagation.inc

+--echo #
+--echo # MDEV-7149 Constant condition propagation erroneously applied for LIKE
+--echo #
+
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+DROP TABLE t1;
+
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+DROP TABLE t1;
+
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+DROP TABLE t1;
+
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+DROP TABLE t1;

mysql-test/include/ctype_like_cond_propagation_utf8_german.inc

+--echo #
+--echo # MDEV-7149 Constant condition propagation erroneously applied for LIKE
+--echo #
+
+CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES ('ae'),('ä');
+SELECT * FROM t1 WHERE c1='ä';
+SELECT * FROM t1 WHERE c1 LIKE 'ae';
+SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+SELECT * FROM t1 WHERE CONCAT(c1)='ä';
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'ae';
+SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+DROP TABLE IF EXISTS t1;

mysql-test/r/ctype_binary.result

@@ -2915,3 +2915,98 @@ SET sql_mode=default;
 #
 # End of 5.5 tests
 #
+#
+# Start of 10.0 tests
+#
+SET NAMES binary;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varbinary(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where 0
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varbinary(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where 0
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varbinary(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where 0
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varbinary(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ('%' = concat(`test`.`t1`.`c1`))
+DROP TABLE t1;
+#
+# End of 10.0 tests
+#

mysql-test/r/ctype_latin1.result

@@ -7659,6 +7659,198 @@ DROP FUNCTION mysql_real_escape_string_generated;
 DROP FUNCTION iswellformed;
 DROP TABLE allbytes;
 # End of ctype_backslash.inc
+SET NAMES latin1;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+SET NAMES latin1 COLLATE latin1_bin;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
 #
 # MDEV-6752 Trailing incomplete characters are not replaced to question marks on conversion
 #

mysql-test/r/ctype_uca.result

@@ -7700,6 +7700,276 @@ DROP TABLE t1;
 # Start of MariaDB-10.0 tests
 #
 
+SET NAMES utf8 COLLATE utf8_unicode_ci;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('ae'),('ä');
+SELECT * FROM t1 WHERE c1='ä';
+c1
+ä
+SELECT * FROM t1 WHERE c1 LIKE 'ae';
+c1
+ae
+SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((`test`.`t1`.`c1` = 'ä') and (`test`.`t1`.`c1` like 'ae'))
+SELECT * FROM t1 WHERE CONCAT(c1)='ä';
+c1
+ä
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'ae';
+c1
+ae
+SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'ä') and (concat(`test`.`t1`.`c1`) like 'ae'))
+DROP TABLE IF EXISTS t1;
+SET NAMES utf8 COLLATE utf8_german2_ci;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_german2_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_german2_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_german2_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_german2_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_german2_ci NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('ae'),('ä');
+SELECT * FROM t1 WHERE c1='ä';
+c1
+ae
+ä
+SELECT * FROM t1 WHERE c1 LIKE 'ae';
+c1
+ae
+SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+c1
+ae
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((`test`.`t1`.`c1` = 'ä') and (`test`.`t1`.`c1` like 'ae'))
+SELECT * FROM t1 WHERE CONCAT(c1)='ä';
+c1
+ae
+ä
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'ae';
+c1
+ae
+SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+c1
+ae
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'ä') and (concat(`test`.`t1`.`c1`) like 'ae'))
+DROP TABLE IF EXISTS t1;
 #
 # MDEV-4929 Myanmar collation
 #

mysql-test/r/ctype_ucs.result

@@ -5326,6 +5326,199 @@ DROP TABLE t1;
 #
 # Start of 10.0 tests
 #
+SET NAMES latin1, collation_connection=ucs2_bin;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 COLLATE ucs2_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 COLLATE ucs2_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 COLLATE ucs2_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 COLLATE ucs2_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+SET NAMES latin1, collation_connection=ucs2_general_ci;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+SET NAMES latin1;
 #
 # MDEV-6661 PI() does not work well in UCS2/UTF16/UTF32 context
 #

mysql-test/r/ctype_utf8.result

@@ -5936,6 +5936,235 @@ set max_sort_length=default;
 #
 # Start of 10.0 tests
 #
+SET NAMES utf8 COLLATE utf8_bin;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+SET NAMES utf8;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE CONCAT(c1)='a';
+c1
+a
+a 
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'a ';
+c1
+a 
+SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='a' AND CONCAT(c1) LIKE 'a ';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'a') and (concat(`test`.`t1`.`c1`) like 'a '))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1);
+c1
+a
+a 
+SELECT * FROM t1 WHERE 'a ' LIKE CONCAT(c1);
+c1
+a 
+SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+c1
+a 
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE 'a'=CONCAT(c1) AND 'a ' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('a' = concat(`test`.`t1`.`c1`)) and ('a ' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '% '=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '% '=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('% ' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT REPEAT('a', 10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('%'),('% ');
+SELECT * FROM t1 WHERE '%'=CONCAT(c1);
+c1
+%
+% 
+SELECT * FROM t1 WHERE 'a' LIKE CONCAT(c1);
+c1
+%
+SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+c1
+%
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE '%'=CONCAT(c1) AND 'a' LIKE CONCAT(c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where (('%' = concat(`test`.`t1`.`c1`)) and ('a' like concat(`test`.`t1`.`c1`)))
+DROP TABLE t1;
+#
+# MDEV-7149 Constant condition propagation erroneously applied for LIKE
+#
+CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(10) CHARACTER SET utf8 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('ae'),('ä');
+SELECT * FROM t1 WHERE c1='ä';
+c1
+ä
+SELECT * FROM t1 WHERE c1 LIKE 'ae';
+c1
+ae
+SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE c1='ä' AND c1 LIKE 'ae';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((`test`.`t1`.`c1` = 'ä') and (`test`.`t1`.`c1` like 'ae'))
+SELECT * FROM t1 WHERE CONCAT(c1)='ä';
+c1
+ä
+SELECT * FROM t1 WHERE CONCAT(c1) LIKE 'ae';
+c1
+ae
+SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+c1
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE CONCAT(c1)='ä' AND CONCAT(c1) LIKE 'ae';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ((concat(`test`.`t1`.`c1`) = 'ä') and (concat(`test`.`t1`.`c1`) like 'ae'))
+DROP TABLE IF EXISTS t1;
 #
 # MDEV-6666 Malformed result for CONCAT(utf8_column, binary_string)
 #

mysql-test/t/ctype_binary.test

@@ -10,3 +10,15 @@ set names binary;
 --echo #
 --echo # End of 5.5 tests
 --echo #
+
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+SET NAMES binary;
+--source include/ctype_like_cond_propagation.inc
+
+--echo #
+--echo # End of 10.0 tests
+--echo #

mysql-test/t/ctype_latin1.test

@@ -210,6 +210,13 @@ set names latin1;
 let $ctype_unescape_combinations=selected;
 --source include/ctype_unescape.inc
 
+SET NAMES latin1;
+--source include/ctype_like_cond_propagation.inc
+
+SET NAMES latin1 COLLATE latin1_bin;
+--source include/ctype_like_cond_propagation.inc
+
+
 --echo #
 --echo # MDEV-6752 Trailing incomplete characters are not replaced to question marks on conversion
 --echo #

mysql-test/t/ctype_uca.test

@@ -571,6 +571,14 @@ SET NAMES utf8mb4 COLLATE utf8mb4_unicode_520_ci;
 --echo #
 --echo
 
+SET NAMES utf8 COLLATE utf8_unicode_ci;
+--source include/ctype_like_cond_propagation.inc
+--source include/ctype_like_cond_propagation_utf8_german.inc
+
+SET NAMES utf8 COLLATE utf8_german2_ci;
+--source include/ctype_like_cond_propagation.inc
+--source include/ctype_like_cond_propagation_utf8_german.inc
+
 --echo #
 --echo # MDEV-4929 Myanmar collation
 --echo #

mysql-test/t/ctype_ucs.test

@@ -897,6 +897,12 @@ DROP TABLE t1;
 --echo # Start of 10.0 tests
 --echo #
 
+SET NAMES latin1, collation_connection=ucs2_bin;
+--source include/ctype_like_cond_propagation.inc
+SET NAMES latin1, collation_connection=ucs2_general_ci;
+--source include/ctype_like_cond_propagation.inc
+SET NAMES latin1;
+
 --echo #
 --echo # MDEV-6661 PI() does not work well in UCS2/UTF16/UTF32 context
 --echo #

mysql-test/t/ctype_utf8.test

@@ -1658,6 +1658,13 @@ set max_sort_length=default;
 --echo # Start of 10.0 tests
 --echo #
 
+SET NAMES utf8 COLLATE utf8_bin;
+--source include/ctype_like_cond_propagation.inc
+SET NAMES utf8;
+--source include/ctype_like_cond_propagation.inc
+--source include/ctype_like_cond_propagation_utf8_german.inc
+
+
 --echo #
 --echo # MDEV-6666 Malformed result for CONCAT(utf8_column, binary_string)
 --echo #

sql/item_cmpfunc.h

@@ -1486,7 +1486,42 @@ class Item_func_like :public Item_bool_func2
   longlong val_int();
   enum Functype functype() const { return LIKE_FUNC; }
   optimize_type select_optimize() const;
-  cond_result eq_cmp_result() const { return COND_TRUE; }
+  cond_result eq_cmp_result() const
+  {
+    /**
+      We cannot always rewrite conditions as follows:
+        from:  WHERE expr1=const AND expr1 LIKE expr2
+        to:    WHERE expr1=const AND const LIKE expr2
+      or
+        from:  WHERE expr1=const AND expr2 LIKE expr1
+        to:    WHERE expr1=const AND expr2 LIKE const
+
+      because LIKE works differently comparing to the regular "=" operator:
+
+      1. LIKE performs a stricter one-character-to-one-character comparison
+         and does not recognize contractions and expansions.
+         Replacing "expr1" to "const in LIKE would make the condition
+         stricter in case of a complex collation.
+
+      2. LIKE does not ignore trailing spaces and thus works differently
+         from the "=" operator in case of "PAD SPACE" collations
+         (which are the majority in MariaDB). So, for "PAD SPACE" collations:
+
+         - expr1=const       - ignores trailing spaces
+         - const LIKE expr2  - does not ignore trailing spaces
+         - expr2 LIKE const  - does not ignore trailing spaces
+
+      Allow only "binary" for now.
+      It neither ignores trailing spaces nor has contractions/expansions.
+
+      TODO:
+      We could still replace "expr1" to "const" in "expr1 LIKE expr2"
+      in case of a "PAD SPACE" collation, but only if "expr2" has '%'
+      at the end.         
+    */
+    return ((Item_func_like *)this)->compare_collation() == &my_charset_bin ?
+           COND_TRUE : COND_OK;
+  }
   const char *func_name() const { return "like"; }
   bool fix_fields(THD *thd, Item **ref);
   void cleanup();