Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized

away.

During optimization stage the WHERE conditions can be changed or even
be removed at all if they know for sure to be true of false. Thus they aren't
showed in the EXPLAIN EXTENDED which prints conditions after optimization.

Now if all elements of an Item_cond were removed this Item_cond is substituted
for an Item_int with the int value of the Item_cond.
If there were conditions that were totally optimized away then values of the
saved cond_value and having_value will be printed instead.


mysql-test/t/explain.test:
  Added a test case for the bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized away.
mysql-test/r/subselect.result:
  Corrected test case result after fix for bug#22331.
mysql-test/r/func_test.result:
  Corrected test case result after fix for bug#22331.
mysql-test/r/explain.result:
  Added a test case for the bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized away.
sql/sql_select.cc:
  Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized
  away.
  Now if all elements of an Item_cond were removed this Item_cond is substituted
  for an Item_int with the int value of the Item_cond.
  If there were conditions that were totally optimized away then values of the
  saved cond_value and having_value will be printed instead.
sql/sql_lex.h:
  Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized
  away.
  The cond_value and the having_value variables are
  added to the SELECT_LEX class.
sql/sql_lex.cc:
  Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized
  away.
  The initialization of the cond_value and the having_value variables.
sql/sql_select.h:
  Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized
  away.
  Now having_value is also stored in the JOIN class.

1 files changed, 8 insertions, 8 deletions

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 06f8c019265..1f29497f662 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -421,7 +421,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1`
+Note	1003	select 1 AS `1` from `test`.`t1` where 1
 drop table t1;
 CREATE TABLE `t1` (
 `numeropost` mediumint(8) unsigned NOT NULL auto_increment,
@@ -1180,7 +1180,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
-Note	1003	select <in_optimizer>(0,<exists>(select 1 AS `Not_used` from `test`.`t1` `a`)) AS `0 IN (SELECT 1 FROM t1 a)`
+Note	1003	select <in_optimizer>(0,<exists>(select 1 AS `Not_used` from `test`.`t1` `a` where 0)) AS `0 IN (SELECT 1 FROM t1 a)`
 INSERT INTO t1 (pseudo) VALUES ('test1');
 SELECT 0 IN (SELECT 1 FROM t1 a);
 0 IN (SELECT 1 FROM t1 a)
@@ -1190,7 +1190,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
-Note	1003	select <in_optimizer>(0,<exists>(select 1 AS `Not_used` from `test`.`t1` `a`)) AS `0 IN (SELECT 1 FROM t1 a)`
+Note	1003	select <in_optimizer>(0,<exists>(select 1 AS `Not_used` from `test`.`t1` `a` where 0)) AS `0 IN (SELECT 1 FROM t1 a)`
 drop table t1;
 CREATE TABLE `t1` (
 `i` int(11) NOT NULL default '0',
@@ -1532,7 +1532,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3`
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= any (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
@@ -1540,7 +1540,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3`
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
@@ -1548,7 +1548,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3`
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
@@ -1556,7 +1556,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3`
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 insert into t2 values (2,2), (2,1), (3,3), (3,1);
 select * from t3 where a > all (select max(b) from t2 group by a);
 a
@@ -1618,7 +1618,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select `test`.`t1`.`s1` AS `s1` from `test`.`t1`
+Note	1003	select `test`.`t1`.`s1` AS `s1` from `test`.`t1` where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');