From b757f734925c80343c262e6ddf8379cc665e7103 Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Fri, 13 May 2011 18:37:28 +0300
Subject: [PATCH 1/3] Fix LP BUG#777597

Analysis:
During optimization of the subquery, in the call chain:

update_ref_and_keys -> add_key_fields ->
merge_key_fields -> Item_direct_ref::is_null -> Item_cache::is_null

The call to Item_cache::is_null() returns TRUE, which is wrong.
This results in Item_null replacing the field 'f3' in the KEY_FIELD,
then this Item_null is used for index access, producing a wrong result.

The reason why Item_cache::is_null returns wrong result is that
this Item_cache object is a cache of the left operand of IN, and was
updated in Item_in_optimizer::val_int. In MWL#89 the latter method is
called during the execution phase, which is after we optimize the subquery.
Therefore during the optization phase the left operand cache of IN was
not updated.

Solution:
Update the left operand cache during optimization if it is a constant.

This bug fix also discoveres and fixes a wrong IF statement in
convert_constant_item().
---
 mysql-test/r/subselect4.result    | 21 ++++++++++++++++++++-
 mysql-test/r/subselect_mat.result |  8 ++++----
 mysql-test/t/subselect4.test      | 22 ++++++++++++++++++++++
 sql/item_cmpfunc.cc               | 15 ++++++++-------
 4 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/mysql-test/r/subselect4.result b/mysql-test/r/subselect4.result
index 87903694230..1d775120ee6 100644
--- a/mysql-test/r/subselect4.result
+++ b/mysql-test/r/subselect4.result
@@ -1317,7 +1317,7 @@ EXPLAIN
 SELECT i FROM t1 WHERE (1) NOT IN (SELECT i FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t2	ref_or_null	k	k	5	const	2	Using where; Using index
+2	DEPENDENT SUBQUERY	t2	index_subquery	k	k	5	const	2	Using index
 DROP TABLE t2;
 DROP TABLE t1;
 #
@@ -1743,3 +1743,22 @@ SELECT f2 FROM t1 WHERE ( f2 ) IN ( SELECT t3.f2 FROM t3 JOIN t2 ON t2.f1 = 1 )
 )
 NULL
 drop table t1, t2, t3;
+#                                                                                                                                                     
+# LP BUG#777597 Wrong result with multipart keys, in_to_exists=on, NOT IN in MWL#89
+#                                                                                                                                                     
+CREATE TABLE t1 ( f4 int);
+INSERT IGNORE INTO t1 VALUES (2),(2);
+CREATE TABLE t2 ( f3 int, f10 int, KEY (f10,f3) );
+INSERT IGNORE INTO t2 VALUES (6, 1), (6, 1);
+CREATE TABLE t3 ( f10 int );
+INSERT IGNORE INTO t3 VALUES (1);
+SET SESSION optimizer_switch='in_to_exists=on,materialization=off';
+EXPLAIN
+SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	DEPENDENT SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
+2	DEPENDENT SUBQUERY	t2	ref_or_null	f10	f10	10	const,const	2	Using where; Using index
+SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
+f4
+drop table t1,t2,t3;
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index f475b251235..144519878c1 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -1395,7 +1395,7 @@ SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
 3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t3	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 f2
 EXPLAIN
@@ -1403,7 +1403,7 @@ SELECT (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 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
 3	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	t3	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1)
 NULL
@@ -1412,7 +1412,7 @@ SELECT * FROM t2 WHERE (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
 3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t3	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT * FROM t2 WHERE (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
 f2
 EXPLAIN
@@ -1420,7 +1420,7 @@ SELECT (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
 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
 3	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	t3	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
 (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1)
 NULL
diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index c57cdf27444..a6baa02bc93 100644
--- a/mysql-test/t/subselect4.test
+++ b/mysql-test/t/subselect4.test
@@ -1412,3 +1412,25 @@ SELECT STRAIGHT_JOIN (
 );
 
 drop table t1, t2, t3;
+
+
+--echo #                                                                                                                                                     
+--echo # LP BUG#777597 Wrong result with multipart keys, in_to_exists=on, NOT IN in MWL#89
+--echo #                                                                                                                                                     
+
+CREATE TABLE t1 ( f4 int);
+INSERT IGNORE INTO t1 VALUES (2),(2);
+
+CREATE TABLE t2 ( f3 int, f10 int, KEY (f10,f3) );
+INSERT IGNORE INTO t2 VALUES (6, 1), (6, 1);
+
+CREATE TABLE t3 ( f10 int );
+INSERT IGNORE INTO t3 VALUES (1);
+
+SET SESSION optimizer_switch='in_to_exists=on,materialization=off';
+
+EXPLAIN
+SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
+SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
+
+drop table t1,t2,t3;
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 547b4c686a2..16eb4777ec6 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -421,14 +421,12 @@ static bool convert_constant_item(THD *thd, Item_field *field_item,
     thd->count_cuted_fields= CHECK_FIELD_IGNORE;
 
     /*
-      Store the value of the field/constant if it references an outer field
-      because the call to save_in_field below overrides that value.
-      Don't save field value if no data has been read yet.
-      Outer constant values are always saved.
+      Store the value of the field/constant because the call to save_in_field
+      below overrides that value. Don't save field value if no data has been
+      read yet.
     */
-    bool save_field_value= (field_item->depended_from &&
-                            (field_item->const_item() ||
-                             !(field->table->status & STATUS_NO_RECORD)));
+    bool save_field_value= (field_item->const_item() ||
+                            !(field->table->status & STATUS_NO_RECORD));
     if (save_field_value)
       orig_field_val= field->val_int();
     if (!(*item)->is_null() && !(*item)->save_in_field(field, 1))
@@ -1743,7 +1741,10 @@ bool Item_in_optimizer::fix_left(THD *thd, Item **ref)
   with_sum_func= args[0]->with_sum_func;
   with_field= args[0]->with_field;
   if ((const_item_cache= args[0]->const_item()))
+  {
     cache->store(args[0]);
+    cache->cache_value();
+  }
   return 0;
 }
 

From 4a9c027ad85597e5bcd42b59245a743366af476a Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Tue, 17 May 2011 00:00:11 +0300
Subject: [PATCH 2/3] Fix LP BUG#778413

Analysis:
The subquery is evaluated first during ref-optimization of the outer
query because the subquery is considered constant from the perspective
of the outer query. Thus an attempt is made to evaluate the MAX subquery
and use the new constant to drive an index nested loops join.
During this evaluation the inner-most subquery replaces the JOIN_TAB
with a new one that fetches the data from a temp table.
The function select_describe crashes at the lines:
        TABLE_LIST *real_table= table->pos_in_table_list;
	item_list.push_back(new Item_string(real_table->alias,
					    strlen(real_table->alias),
					    cs));
because 'table' is a temp table, and it has no corresponding table
reference. This 'real_table' is NULL, and real_table->alias results
in a crash.

Solution:
In the spirit of MWL#89 prevent the evaluation of expensive predicates
during optimization. This patch prevents the evaluation of expensive
predicates during ref optimization.


sql/item_subselect.h:
  Remove unused class member. Not needed for the fix, but noticed now and removed.
---
 mysql-test/r/group_min_max.result         |  2 +-
 mysql-test/r/subselect.result             |  4 ++--
 mysql-test/r/subselect4.result            | 20 ++++++++++++++++++++
 mysql-test/r/subselect_no_mat.result      |  4 ++--
 mysql-test/r/subselect_no_opts.result     |  4 ++--
 mysql-test/r/subselect_no_semijoin.result |  4 ++--
 mysql-test/t/subselect4.test              | 23 +++++++++++++++++++++++
 sql/item_cmpfunc.cc                       |  2 +-
 sql/item_subselect.h                      |  1 -
 sql/sql_select.cc                         |  4 ++--
 10 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/mysql-test/r/group_min_max.result b/mysql-test/r/group_min_max.result
index 20b0c054480..0b3df689089 100644
--- a/mysql-test/r/group_min_max.result
+++ b/mysql-test/r/group_min_max.result
@@ -2412,7 +2412,7 @@ EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2
 ON t1_outer1.a = (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) 
 AND t1_outer1.b = t1_outer2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer1	ref	a	a	5	const	1	Using where; Using index
+1	PRIMARY	t1_outer1	ref	a	a	5	const	1	Using index
 1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer (flat, BNL join)
 2	SUBQUERY	t1	range	NULL	a	5	NULL	8	Using index for group-by
 EXPLAIN SELECT (SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 0b7d9942297..66c8493ca4a 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -370,7 +370,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37		1	100.00	Using index
 Warnings:
-Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -549,7 +549,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 Warnings:
-Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1'))
+Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1') and ('3' = 3))
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
diff --git a/mysql-test/r/subselect4.result b/mysql-test/r/subselect4.result
index 1d775120ee6..e22a0f04a4d 100644
--- a/mysql-test/r/subselect4.result
+++ b/mysql-test/r/subselect4.result
@@ -1762,3 +1762,23 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
 f4
 drop table t1,t2,t3;
+#                                                                                                                                                     
+# LP BUG#778413 Third crash in select_describe() in maria-5.3-mwl89
+#                                                                                                                                                     
+CREATE TABLE t1 ( f11 int) ;
+INSERT INTO t1 VALUES (1),(1);
+CREATE TABLE t2 ( f1 int NOT NULL) ;
+INSERT INTO t2 VALUES (20);
+CREATE TABLE t3 (f3 int) ;
+INSERT INTO t3 VALUES (2),(2);
+EXPLAIN SELECT * FROM t2
+WHERE t2.f1 = (
+SELECT MAX( f3 ) FROM t3
+WHERE EXISTS (
+SELECT DISTINCT f11
+FROM t1));
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+drop table t1, t2, t3;
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index 8bde2ee1260..a83baf53fb7 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -374,7 +374,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37		1	100.00	Using index
 Warnings:
-Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -553,7 +553,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 Warnings:
-Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1'))
+Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1') and ('3' = 3))
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 24d652b7bd8..14711c30a7f 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -371,7 +371,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37		1	100.00	Using index
 Warnings:
-Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -550,7 +550,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 Warnings:
-Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1'))
+Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1') and ('3' = 3))
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index 5f8cb80e6cc..2fb737aad1e 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -371,7 +371,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37		1	100.00	Using index
 Warnings:
-Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -550,7 +550,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 Warnings:
-Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1'))
+Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1') and ('3' = 3))
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index a6baa02bc93..33a6329401f 100644
--- a/mysql-test/t/subselect4.test
+++ b/mysql-test/t/subselect4.test
@@ -1434,3 +1434,26 @@ SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t
 SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
 
 drop table t1,t2,t3;
+
+
+--echo #                                                                                                                                                     
+--echo # LP BUG#778413 Third crash in select_describe() in maria-5.3-mwl89
+--echo #                                                                                                                                                     
+
+CREATE TABLE t1 ( f11 int) ;
+INSERT INTO t1 VALUES (1),(1);
+
+CREATE TABLE t2 ( f1 int NOT NULL) ;
+INSERT INTO t2 VALUES (20);
+
+CREATE TABLE t3 (f3 int) ;
+INSERT INTO t3 VALUES (2),(2);
+
+EXPLAIN SELECT * FROM t2
+WHERE t2.f1 = (
+        SELECT MAX( f3 ) FROM t3
+        WHERE EXISTS (
+                SELECT DISTINCT f11
+                FROM t1));
+
+drop table t1, t2, t3;
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 16eb4777ec6..c7f661e011c 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -5755,7 +5755,7 @@ void Item_equal::update_const()
   Item *item;
   while ((item= it++))
   {
-    if (item->const_item())
+    if (item->const_item() && !item->is_expensive())
     {
       if (item == equal_items.head())
         with_const= TRUE;
diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index 2c357b0da20..8d2580cc604 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -619,7 +619,6 @@ protected:
 class subselect_single_select_engine: public subselect_engine
 {
   bool prepared; /* simple subselect is prepared */
-  bool optimized; /* simple subselect is optimized */
   bool executed; /* simple subselect is executed */
   st_select_lex *select_lex; /* corresponding select_lex */
   JOIN * join; /* corresponding JOIN structure */
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 0bbe77486ce..6bd997eaddf 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -9469,7 +9469,7 @@ static bool check_simple_equality(Item *left_item, Item *right_item,
     Item *orig_field_item= 0;
     if (left_item->type() == Item::FIELD_ITEM &&
         !((Item_field*)left_item)->depended_from &&
-        right_item->const_item())
+        right_item->const_item() && !right_item->is_expensive())
     {
       orig_field_item= left_item;
       field_item= (Item_field *) left_item;
@@ -9477,7 +9477,7 @@ static bool check_simple_equality(Item *left_item, Item *right_item,
     }
     else if (right_item->type() == Item::FIELD_ITEM &&
              !((Item_field*)right_item)->depended_from &&
-             left_item->const_item())
+             left_item->const_item() && !left_item->is_expensive())
     {
       orig_field_item= right_item;
       field_item= (Item_field *) right_item;

From 920d4677033ab46cfe273697a2026901228c8c72 Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Tue, 17 May 2011 10:35:24 +0300
Subject: [PATCH 3/3] LP BUG#778413

Adjusted test results for tests not run by default on Linux.

mysql-test/suite/pbxt/r/subselect.result:
  lp:778413
---
 mysql-test/r/windows.result                  | 2 +-
 mysql-test/suite/pbxt/r/group_min_max.result | 2 +-
 mysql-test/suite/pbxt/r/subselect.result     | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/mysql-test/r/windows.result b/mysql-test/r/windows.result
index d0cdd858d4a..dc624a07f4f 100644
--- a/mysql-test/r/windows.result
+++ b/mysql-test/r/windows.result
@@ -16,7 +16,7 @@ CREATE TABLE t1 (a int, b int);
 INSERT INTO t1 VALUES (1,1);
 EXPLAIN SELECT * FROM t1 WHERE b =  (SELECT max(2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 DROP TABLE t1;
 CREATE DATABASE `TESTDB`;
diff --git a/mysql-test/suite/pbxt/r/group_min_max.result b/mysql-test/suite/pbxt/r/group_min_max.result
index 04f14a9f5e7..ab00cdeff59 100644
--- a/mysql-test/suite/pbxt/r/group_min_max.result
+++ b/mysql-test/suite/pbxt/r/group_min_max.result
@@ -2267,7 +2267,7 @@ EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2
 ON t1_outer1.a = (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) 
 AND t1_outer1.b = t1_outer2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer1	ref	a	a	5	const	1	Using where; Using index
+1	PRIMARY	t1_outer1	ref	a	a	5	const	1	Using index
 1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer (flat, BNL join)
 2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
 EXPLAIN SELECT (SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
diff --git a/mysql-test/suite/pbxt/r/subselect.result b/mysql-test/suite/pbxt/r/subselect.result
index daa13af72bc..399635a2536 100644
--- a/mysql-test/suite/pbxt/r/subselect.result
+++ b/mysql-test/suite/pbxt/r/subselect.result
@@ -367,7 +367,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37		1	100.00	Using index
 Warnings:
-Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where ('joce' = (select 'joce' from `test`.`t8` where 1))
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -546,7 +546,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 Warnings:
-Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1'))
+Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = '1') and ('3' = 3))
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);