MDEV-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'

Note, the patch for MDEV-8661 unintentionally fixed MDEV-8694 as well,
as a side effect. Adding a real clear fix: implementing
Item_func_like::propagate_equal_fields() with comments.

include/m_ctype.h

@@ -201,6 +201,10 @@ extern MY_UNI_CTYPE my_uni_ctype[256];
 #define MY_CS_UNICODE_SUPPLEMENT 16384 /* Non-BMP Unicode characters */
 #define MY_CS_LOWER_SORT 32768 /* If use lower case as weight   */
 #define MY_CS_STRNXFRM_BAD_NWEIGHTS 0x10000 /* strnxfrm ignores "nweights" */
+#define MY_CS_NOPAD   0x20000  /* if does not ignore trailing spaces */
+#define MY_CS_NON1TO1 0x40000  /* Has a complex mapping from characters
+                                  to weights, e.g. contractions, expansions,
+                                  ignorable characters */
 #define MY_CHARSET_UNDEFINED 0
 
 /* Character repertoire flags */

mysql-test/include/ctype_like_cond_propagation.inc

@@ -37,3 +37,19 @@ 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;
+
+--echo #
+--echo # MDEV-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+--echo #
+
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+DROP TABLE t1;
+
+--echo #
+--echo # End of MDEV-8694
+--echo #

mysql-test/r/ctype_binary.result

@@ -3008,6 +3008,31 @@ Warnings:
 Note	1003	select `test`.`t1`.`c1` AS `c1` from `test`.`t1` where ('%' = concat(`test`.`t1`.`c1`))
 DROP TABLE t1;
 #
+# MDEV-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varbinary(10) NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where (`test`.`t1`.`a` = 'a')
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
+#
 # MDEV-7629 Regression: Bit and hex string literals changed column names in 10.0.14
 #
 SELECT _binary 0x7E, _binary X'7E', _binary B'01111110';

mysql-test/r/ctype_cp1250_ch.result

@@ -105,6 +105,126 @@ SET character_set_server= @safe_character_set_server;
 SET collation_server= @safe_collation_server;
 SET character_set_client= @safe_character_set_client;
 SET character_set_results= @safe_character_set_results;
+#
+# 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
+) 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
+) 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
+) 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
+) 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET utf8 NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((not((`test`.`t1`.`a` like 'a '))) and (`test`.`t1`.`a` = 'a'))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 SET @test_character_set= 'cp1250';
 SET @test_collation= 'cp1250_czech_cs';
 SET @safe_character_set_server= @@character_set_server;

mysql-test/r/ctype_latin1.result

@@ -7755,6 +7755,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 SET NAMES latin1 COLLATE latin1_bin;
 #
 # MDEV-7149 Constant condition propagation erroneously applied for LIKE
@@ -7852,6 +7877,31 @@ 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
+#
 # MDEV-6752 Trailing incomplete characters are not replaced to question marks on conversion
 #
 SET NAMES utf8, character_set_connection=latin1;

mysql-test/r/ctype_latin2_ch.result

@@ -45,6 +45,126 @@ strcmp('a\t','a' )
 SELECT strcmp('a\t','a ');
 strcmp('a\t','a ')
 0
+#
+# 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 latin2 COLLATE latin2_czech_cs NOT NULL
+) 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 latin2 COLLATE latin2_czech_cs NOT NULL
+) 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 latin2 COLLATE latin2_czech_cs NOT NULL
+) 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 latin2 COLLATE latin2_czech_cs NOT NULL
+) 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET latin2 COLLATE latin2_czech_cs NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 create table t1 (
 a varchar(2) character set latin2 collate latin2_czech_cs,
 primary key(a)

mysql-test/r/ctype_tis620.result

@@ -3115,6 +3115,126 @@ Zz	5A,7A
 ~	7E
 	7F
 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 tis620 NOT NULL
+) 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 tis620 NOT NULL
+) 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 tis620 NOT NULL
+) 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 tis620 NOT NULL
+) 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET tis620 NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 SET collation_connection='tis620_bin';
 create table t1 select repeat('a',4000) a;
 delete from t1;
@@ -3212,6 +3332,126 @@ c2h
 ab_def
 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 tis620 COLLATE tis620_bin NOT NULL
+) 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 tis620 COLLATE tis620_bin NOT NULL
+) 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 tis620 COLLATE tis620_bin NOT NULL
+) 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 tis620 COLLATE tis620_bin NOT NULL
+) 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET tis620 COLLATE tis620_bin NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
+#
 # Start of 5.6 tests
 #
 #

mysql-test/r/ctype_uca.result

@@ -8285,6 +8285,31 @@ 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((not((`test`.`t1`.`a` like 'a '))) and (`test`.`t1`.`a` = 'a'))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
+#
 # MDEV-7149 Constant condition propagation erroneously applied for LIKE
 #
 CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;
@@ -8418,6 +8443,31 @@ 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET utf8 COLLATE utf8_german2_ci NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((not((`test`.`t1`.`a` like 'a '))) and (`test`.`t1`.`a` = 'a'))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
+#
 # MDEV-7149 Constant condition propagation erroneously applied for LIKE
 #
 CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;

mysql-test/r/ctype_ucs.result

@@ -5446,6 +5446,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET ucs2 COLLATE ucs2_bin NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	2
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	2
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 SET NAMES latin1, collation_connection=ucs2_general_ci;
 #
 # MDEV-7149 Constant condition propagation erroneously applied for LIKE
@@ -5542,6 +5567,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET ucs2 NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	2
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	2
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 SET NAMES latin1;
 #
 # MDEV-6661 PI() does not work well in UCS2/UTF16/UTF32 context

mysql-test/r/ctype_utf8.result

@@ -6775,6 +6775,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (not((`test`.`t1`.`a` like 'a '))))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
 SET NAMES utf8;
 #
 # MDEV-7149 Constant condition propagation erroneously applied for LIKE
@@ -6872,6 +6897,31 @@ 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-8694 Wrong result for SELECT..WHERE a NOT LIKE 'a ' AND a='a'
+#
+CREATE TABLE t1 AS SELECT SPACE(10) AS a LIMIT 0;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(10) CHARACTER SET utf8 NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES ('a'),('a ');
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ';
+a	LENGTH(a)
+a	1
+SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='a';
+a	LENGTH(a)
+a	1
+EXPLAIN EXTENDED SELECT a, LENGTH(a) FROM t1 WHERE a NOT LIKE 'a ' AND a='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`.`a` AS `a`,length(`test`.`t1`.`a`) AS `LENGTH(a)` from `test`.`t1` where ((not((`test`.`t1`.`a` like 'a '))) and (`test`.`t1`.`a` = 'a'))
+DROP TABLE t1;
+#
+# End of MDEV-8694
+#
+#
 # MDEV-7149 Constant condition propagation erroneously applied for LIKE
 #
 CREATE TABLE t1 AS SELECT REPEAT('a',10) AS c1 LIMIT 0;

mysql-test/t/ctype_cp1250_ch.test

@@ -12,6 +12,7 @@ SHOW COLLATION LIKE 'cp1250_czech_cs';
 SET @test_character_set= 'cp1250';
 SET @test_collation= 'cp1250_general_ci';
 -- source include/ctype_common.inc
+-- source include/ctype_like_cond_propagation.inc
 
 SET @test_character_set= 'cp1250';
 SET @test_collation= 'cp1250_czech_cs';

mysql-test/t/ctype_latin2_ch.test

@@ -33,6 +33,7 @@ drop table t1;
 
 set names latin2 collate latin2_czech_cs;
 --source include/ctype_pad_space.inc
+--source include/ctype_like_cond_propagation.inc
 
 # We can not use ctype_filesort.inc because
 # order of SPACE and TAB is not strict

mysql-test/t/ctype_tis620.test

@@ -157,9 +157,11 @@ SET collation_connection='tis620_thai_ci';
 -- source include/ctype_filesort.inc
 -- source include/ctype_like_escape.inc
 --source include/ctype_ascii_order.inc
+-- source include/ctype_like_cond_propagation.inc
 SET collation_connection='tis620_bin';
 -- source include/ctype_filesort.inc
 -- source include/ctype_like_escape.inc
+-- source include/ctype_like_cond_propagation.inc
 
 # End of 4.1 tests
 

sql/item_cmpfunc.h

@@ -1614,6 +1614,38 @@ class Item_func_like :public Item_bool_func2
            Item_bool_func2::get_mm_tree(param, cond_ptr) :
            Item_func::get_mm_tree(param, cond_ptr);
   }
+  Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond)
+  {
+    /*
+      LIKE differs from the regular comparison operator ('=') in the following:
+      - LIKE never ignores trailing spaces (even for PAD SPACE collations)
+        Propagation of equal fields with a PAD SPACE collation into LIKE
+        is not safe.
+        Example:
+          WHERE a='a ' AND a LIKE 'a'     - returns true for 'a'
+        cannot be rewritten to:
+          WHERE a='a ' AND 'a ' LIKE 'a'  - returns false for 'a'
+        Note, binary collations in MySQL/MariaDB, e.g. latin1_bin,
+        still have the PAD SPACE attribute and ignore trailing spaces!
+      - LIKE does not take into account contractions, expansions,
+        and ignorable characters.
+        Propagation of equal fields with contractions/expansions/ignorables
+        is also not safe.
+
+      It's safe to propagate my_charset_bin (BINARY/VARBINARY/BLOB) values,
+      because they do not ignore trailing spaces and have one-to-one mapping
+      between a string and its weights.
+      The below condition should be true only for my_charset_bin
+      (as of version 10.1.7).
+    */
+    uint flags= Item_func_like::compare_collation()->state;
+    if ((flags & MY_CS_NOPAD) && !(flags & MY_CS_NON1TO1))
+      Item_args::propagate_equal_fields(thd,
+                                        Context(ANY_SUBST,
+                                        compare_collation()),
+                                        cond);
+    return this;
+  }
   const char *func_name() const { return "like"; }
   bool fix_fields(THD *thd, Item **ref);
   void fix_length_and_dec()

strings/ctype-bin.c

@@ -557,7 +557,7 @@ static MY_CHARSET_HANDLER my_charset_handler=
 struct charset_info_st my_charset_bin =
 {
     63,0,0,			/* number        */
-    MY_CS_COMPILED|MY_CS_BINSORT|MY_CS_PRIMARY,/* state */
+    MY_CS_COMPILED|MY_CS_BINSORT|MY_CS_PRIMARY|MY_CS_NOPAD,/* state */
     "binary",			/* cs name    */
     "binary",			/* name          */
     "",				/* comment       */

strings/ctype-czech.c

@@ -625,7 +625,8 @@ static MY_COLLATION_HANDLER my_collation_latin2_czech_ci_handler =
 struct charset_info_st my_charset_latin2_czech_ci =
 {
     2,0,0,                                      /* number    */
-    MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_CSSORT|MY_CS_STRNXFRM_BAD_NWEIGHTS, /* state     */
+    MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_CSSORT|
+    MY_CS_STRNXFRM_BAD_NWEIGHTS|MY_CS_NON1TO1,  /* state     */
     "latin2",                                   /* cs name   */
     "latin2_czech_cs",                          /* name      */
     "",                                         /* comment   */

strings/ctype-latin1.c

@@ -736,7 +736,7 @@ static MY_COLLATION_HANDLER my_collation_german2_ci_handler=
 struct charset_info_st my_charset_latin1_german2_ci=
 {
   31,0,0,				/* number    */
-  MY_CS_COMPILED|MY_CS_STRNXFRM,	/* state     */
+  MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_NON1TO1, /* state     */
   "latin1",				/* cs name    */
   "latin1_german2_ci",			/* name      */
   "",					/* comment   */

strings/ctype-tis620.c

@@ -897,7 +897,7 @@ static MY_CHARSET_HANDLER my_charset_handler=
 struct charset_info_st my_charset_tis620_thai_ci=
 {
     18,0,0,		/* number    */
-    MY_CS_COMPILED|MY_CS_PRIMARY|MY_CS_STRNXFRM,	/* state     */
+    MY_CS_COMPILED|MY_CS_PRIMARY|MY_CS_STRNXFRM|MY_CS_NON1TO1, /* state     */
     "tis620",		/* cs name    */
     "tis620_thai_ci",	/* name      */
     "",			/* comment   */

strings/ctype-win1250ch.c

@@ -690,7 +690,8 @@ static MY_COLLATION_HANDLER my_collation_czech_ci_handler =
 struct charset_info_st my_charset_cp1250_czech_ci =
 {
   34,0,0,                                     /* number    */
-  MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_CSSORT|MY_CS_STRNXFRM_BAD_NWEIGHTS, /* state     */
+  MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_CSSORT|
+  MY_CS_STRNXFRM_BAD_NWEIGHTS|MY_CS_NON1TO1,  /* state     */
   "cp1250",                                   /* cs name   */
   "cp1250_czech_cs",                          /* name      */
   "",                                         /* comment   */