Fixed LP bug #939009.

The result of materialization of the right part of an IN subquery predicate
is placed into a temporary table. Each row of the materialized table is
distinct. A unique key over all fields of the temporary table is defined and
created. It allows to perform key look-ups into the table.
The table created for a materialized subquery can be accessed by key as
any other table. The function best_access-path search for the best access
to join a table to a given partial join. With some where conditions this
function considers a possibility of a ref_or_null access. If such access
employs the unique key on the temporary table then when estimating
the cost this access the function tries to use the array rec_per_key. Yet,
such array is not built for this unique key. This causes a crash of the server.

Rows returned by the subquery that contain nulls don't have to be placed
into temporary table, as they cannot be match any row produced by the
left part of the subquery predicate. So all fields of the temporary table
can be defined as non-nullable. In this case any ref_or_null access
to the temporary table does not make any sense and it does not make sense
to estimate such an access.

The fix makes sure that the temporary table for a materialized IN subquery
is defined with columns that are all non-nullable. The also ensures that 
any row with nulls returned by the subquery is not placed into the
temporary table.  

mysql-test/r/derived_view.result

@@ -1458,14 +1458,14 @@ WHERE (t2.a ,t1.b) NOT IN (SELECT DISTINCT c,a  FROM t3 t);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t	ref	PRIMARY,c	c	4	func	2	Using where; Using index
+2	DEPENDENT SUBQUERY	t	eq_ref	PRIMARY,c	PRIMARY	4	func	1	Using where
 EXPLAIN 
 SELECT * FROM t1 , t2
 WHERE (t2.a ,t1.b) NOT IN (SELECT DISTINCT c,a  FROM (SELECT * FROM t3) t);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t3	ref	PRIMARY,c	c	4	func	2	Using where; Using index
+2	DEPENDENT SUBQUERY	t3	eq_ref	PRIMARY,c	PRIMARY	4	func	1	Using where
 SELECT * FROM t1 , t2
 WHERE (t2.a ,t1.b) NOT IN (SELECT DISTINCT c,a  FROM (SELECT * FROM t3) t);
 b	a

mysql-test/r/func_group.result

@@ -1845,7 +1845,7 @@ NULL
 EXPLAIN EXTENDED
 SELECT MAX(a) FROM t1 WHERE (1,2) IN (SELECT a,b FROM t2 WHERE b<5) and a<10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
 1	PRIMARY	t1	range	a	a	4	NULL	4	100.00	Using where; Using index; Using join buffer (flat, BNL join)
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 Warnings:

mysql-test/r/group_min_max.result

@@ -2407,7 +2407,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	8	Using where
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	8	
 1	PRIMARY	t1_outer	ref	a	a	5	<subquery2>.max(b)	2	Using index
 2	MATERIALIZED	t1	range	NULL	a	5	NULL	8	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer GROUP BY a HAVING 

mysql-test/r/subselect.result

@@ -2973,7 +2973,7 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cac
 explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
@@ -3563,7 +3563,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	Using where
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
@@ -3575,7 +3575,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	a	NULL	NULL	NULL	9	Using where
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 DROP TABLE t1;
 create table t1( f1 int,f2 int);
@@ -4471,14 +4471,14 @@ SET @save_join_cache_level=@@join_cache_level;
 SET join_cache_level=0;
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
 Note	1003	select 1 AS `1` from  <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`min(a)` = 1)
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) FROM t1 WHERE a > 3 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
@@ -5585,7 +5585,7 @@ WHERE col_varchar_nokey IN
 (SELECT col_varchar_key FROM it1 WHERE col_int_key IS NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it1	ref	idx_cvk_cik	idx_cvk_cik	9	const,const	1	Using where; Using index
 SELECT col_int_nokey FROM ot 
 WHERE col_varchar_nokey IN 
@@ -5598,7 +5598,7 @@ WHERE (col_varchar_nokey, 'x') IN
 (SELECT col_varchar_key, col_varchar_key2 FROM it2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 2	MATERIALIZED	it2	ref	idx_cvk_cvk2_cik,idx_cvk_cik	idx_cvk_cvk2_cik	8	const,const	1	Using where; Using index
 SELECT col_int_nokey FROM ot
 WHERE (col_varchar_nokey, 'x') IN

mysql-test/r/subselect4.result

@@ -1249,7 +1249,7 @@ EXPLAIN
 SELECT * FROM (t2 LEFT JOIN t1 ON t1.c1) LEFT JOIN t3 on t3.c1 WHERE 's' IN (SELECT c1 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	0	const row not found
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -1258,7 +1258,7 @@ c1	c1	c1
 EXPLAIN
 SELECT * FROM t4 LEFT JOIN t2 ON t4.c1 WHERE 's' IN (SELECT c1 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t4	index	NULL	PRIMARY	3	NULL	2	Using index; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where

mysql-test/r/subselect_mat.result

@@ -1473,7 +1473,7 @@ SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t2	range	PRIMARY	PRIMARY	4	NULL	2	Using index condition; Rowid-ordered scan
 SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 pk
@@ -1861,6 +1861,39 @@ WHERE 'condition'='impossible'
 MIN(a)
 NULL
 DROP TABLE t1;
+#
+# BUG#939009: Crash with aggregate function in IN subquery 
+#
+SET @save_optimizer_switch=@@optimizer_switch;
+SET optimizer_switch='materialization=on,semijoin=on';
+CREATE TABLE t1 (a int, b int);
+INSERT INTO t1 VALUES (7,1), (4,2), (7,7);
+CREATE TABLE t2 ( c INT );
+INSERT INTO t2 VALUES (4), (7), (6);
+EXPLAIN EXTENDED
+SELECT * FROM t1
+WHERE a IN (SELECT MAX(c) FROM t2) AND b=7 AND (a IS NULL OR a=b);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	Using where
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from  <materialize> (select max(`test`.`t2`.`c`) from `test`.`t2`) join `test`.`t1` where ((`test`.`t1`.`a` = `<subquery2>`.`MAX(c)`) and (`test`.`t1`.`b` = 7) and (isnull(`<subquery2>`.`MAX(c)`) or (`<subquery2>`.`MAX(c)` = 7)))
+SELECT * FROM t1
+WHERE a IN (SELECT MAX(c) FROM t2) AND b=7 AND (a IS NULL OR a=b);
+a	b
+EXPLAIN
+SELECT * FROM t1
+WHERE a IN (SELECT MAX(c) FROM t2 WHERE c < 4) AND b=7 AND (a IS NULL OR a=b);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	Using where
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+SELECT * FROM t1
+WHERE a IN (SELECT MAX(c) FROM t2 WHERE c < 4) AND b=7 AND (a IS NULL OR a=b);
+a	b
+SET optimizer_switch=@save_optimizer_switch;
+DROP TABLE t1,t2;
 # This must be at the end:
 set optimizer_switch=@subselect_sj_mat_tmp;
 set join_cache_level=@save_join_cache_level;
@@ -1983,7 +2016,7 @@ SET @@optimizer_switch='default,semijoin=on,materialization=on';
 EXPLAIN SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t2	range	PRIMARY	PRIMARY	4	NULL	2	Using index condition
 SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 pk

mysql-test/r/subselect_mat_cost.result

@@ -348,7 +348,7 @@ FROM City LEFT JOIN Country ON (Country = Code and City.Population < 10000))
 AND Language IN ('English','Spanish');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	CountryLanguage	range	Language	Language	30	NULL	72	Using index condition; Using where; Rowid-ordered scan
-2	DEPENDENT SUBQUERY	City	ref	CityName	CityName	35	func	2	Using index condition; Using where
+2	DEPENDENT SUBQUERY	City	ref	CityName	CityName	35	func	1	Using index condition; Using where
 2	DEPENDENT SUBQUERY	Country	eq_ref	PRIMARY	PRIMARY	3	world.City.Country	1	Using where; Using index
 select count(*)
 from CountryLanguage

mysql-test/r/subselect_no_scache.result

@@ -2979,7 +2979,7 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<in_optim
 explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
@@ -3569,7 +3569,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	Using where
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
@@ -3581,7 +3581,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	a	NULL	NULL	NULL	9	Using where
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 DROP TABLE t1;
 create table t1( f1 int,f2 int);
@@ -4477,14 +4477,14 @@ SET @save_join_cache_level=@@join_cache_level;
 SET join_cache_level=0;
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
 Note	1003	select 1 AS `1` from  <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`min(a)` = 1)
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) FROM t1 WHERE a > 3 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
@@ -5591,7 +5591,7 @@ WHERE col_varchar_nokey IN
 (SELECT col_varchar_key FROM it1 WHERE col_int_key IS NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it1	ref	idx_cvk_cik	idx_cvk_cik	9	const,const	1	Using where; Using index
 SELECT col_int_nokey FROM ot 
 WHERE col_varchar_nokey IN 
@@ -5604,7 +5604,7 @@ WHERE (col_varchar_nokey, 'x') IN
 (SELECT col_varchar_key, col_varchar_key2 FROM it2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 2	MATERIALIZED	it2	ref	idx_cvk_cvk2_cik,idx_cvk_cik	idx_cvk_cvk2_cik	8	const,const	1	Using where; Using index
 SELECT col_int_nokey FROM ot
 WHERE (col_varchar_nokey, 'x') IN

mysql-test/r/subselect_sj.result

@@ -802,7 +802,7 @@ INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii','iiii','ffff','ffff','ffff','f
 EXPLAIN EXTENDED SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	13	func,func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	11	func,func	1	100.00	
 2	MATERIALIZED	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Rowid-ordered scan
 Warnings:
 Note	1003	select `test`.`t1`.`pk` AS `pk` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`pk` > 0))
@@ -1053,8 +1053,8 @@ AND t1.val IN (SELECT t3.val FROM t3
 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	14	func	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	14	func	1	
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	13	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	13	func	1	
 3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 SELECT *
@@ -1633,9 +1633,9 @@ select * from t1 A, t1 B
 where A.a = B.a and A.a in (select a from t2 C) and B.a in (select a from t2 D);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	C	ALL	NULL	NULL	NULL	NULL	3	
 3	MATERIALIZED	D	ALL	NULL	NULL	NULL	NULL	3	
 drop table t1, t2;
@@ -2323,7 +2323,7 @@ explain
 SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
 2	MATERIALIZED	t2	ref	b	b	4	test.t3.a	1	Using index
 SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
@@ -2443,7 +2443,7 @@ EXPLAIN
 SELECT * FROM t1 RIGHT JOIN t2 ON b = a WHERE t2.b IN (SELECT c FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	2	
 SELECT * FROM t1 RIGHT JOIN t2 ON b = a WHERE t2.b IN (SELECT c FROM t3);

mysql-test/r/subselect_sj2.result

@@ -183,7 +183,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -251,7 +251,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -292,7 +292,7 @@ from t0 where a in
 (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	func	1	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func	1	Using where
 2	MATERIALIZED	t1	index	a	a	5	NULL	10	Using where; Using index
 2	MATERIALIZED	t2	ref	a	a	5	test.t1.a	1	Using index
 2	MATERIALIZED	t3	ref	a	a	5	test.t1.a	1	Using index
@@ -721,7 +721,7 @@ The following must use loose index scan over t3, key a:
 explain select count(a) from t2 where a in ( SELECT  a FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	1000	Using index
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)
@@ -878,7 +878,7 @@ SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	
 2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	

mysql-test/r/subselect_sj2_jcl6.result

@@ -133,7 +133,7 @@ set max_heap_table_size= @save_max_heap_table_size;
 explain select * from t1 where a in (select b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t2	index	b	b	5	NULL	20	Using index
 select * from t1;
 a	b
@@ -195,7 +195,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -263,7 +263,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -304,7 +304,7 @@ from t0 where a in
 (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	func	1	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func	1	Using where
 2	MATERIALIZED	t1	index	a	a	5	NULL	10	Using where; Using index
 2	MATERIALIZED	t2	ref	a	a	5	test.t1.a	1	Using index
 2	MATERIALIZED	t3	ref	a	a	5	test.t1.a	1	Using index
@@ -735,7 +735,7 @@ The following must use loose index scan over t3, key a:
 explain select count(a) from t2 where a in ( SELECT  a FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	1000	Using index
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)
@@ -892,7 +892,7 @@ SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	5	test.t3.a	1	Using where; Using join buffer (flat, BNLH join)
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (incremental, BNL join)
 2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	
@@ -990,7 +990,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	
 SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
 a	b
@@ -999,7 +999,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE b IN (SELECT max(a) FROM t2 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	Using where
-1	PRIMARY	<subquery2>	hash_ALL	distinct_key	#hash#distinct_key	5	test.t1.b	1	Using join buffer (flat, BNLH join)
+1	PRIMARY	<subquery2>	hash_ALL	distinct_key	#hash#distinct_key	4	test.t1.b	1	Using join buffer (flat, BNLH join)
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	Using temporary
 SELECT * FROM t1 WHERE b IN (SELECT max(a) FROM t2 GROUP BY a);
 a	b

mysql-test/r/subselect_sj2_mat.result

@@ -185,7 +185,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -253,7 +253,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -294,7 +294,7 @@ from t0 where a in
 (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	func	1	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func	1	Using where
 2	MATERIALIZED	t1	index	a	a	5	NULL	10	Using where; Using index
 2	MATERIALIZED	t2	ref	a	a	5	test.t1.a	1	Using index
 2	MATERIALIZED	t3	ref	a	a	5	test.t1.a	1	Using index
@@ -723,7 +723,7 @@ The following must use loose index scan over t3, key a:
 explain select count(a) from t2 where a in ( SELECT  a FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	1000	Using index
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)
@@ -880,7 +880,7 @@ SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	
 2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	

mysql-test/r/subselect_sj_jcl6.result

@@ -815,7 +815,7 @@ INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii','iiii','ffff','ffff','ffff','f
 EXPLAIN EXTENDED SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	13	func,func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	11	func,func	1	100.00	
 2	MATERIALIZED	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Rowid-ordered scan
 Warnings:
 Note	1003	select `test`.`t1`.`pk` AS `pk` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`pk` > 0))
@@ -1066,8 +1066,8 @@ AND t1.val IN (SELECT t3.val FROM t3
 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	14	func	1	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	14	func	1	
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	13	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	13	func	1	
 3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 SELECT *
@@ -1646,9 +1646,9 @@ select * from t1 A, t1 B
 where A.a = B.a and A.a in (select a from t2 C) and B.a in (select a from t2 D);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	C	ALL	NULL	NULL	NULL	NULL	3	
 3	MATERIALIZED	D	ALL	NULL	NULL	NULL	NULL	3	
 drop table t1, t2;
@@ -1993,7 +1993,7 @@ explain extended
 SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE t2.f3 IN (SELECT * FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (incremental, BNL join)
 2	MATERIALIZED	t4	index	f2	f2	5	NULL	2	100.00	Using index
@@ -2337,7 +2337,7 @@ explain
 SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
 2	MATERIALIZED	t2	ref	b	b	4	test.t3.a	1	Using index
 SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
@@ -2457,7 +2457,7 @@ EXPLAIN
 SELECT * FROM t1 RIGHT JOIN t2 ON b = a WHERE t2.b IN (SELECT c FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	2	
 SELECT * FROM t1 RIGHT JOIN t2 ON b = a WHERE t2.b IN (SELECT c FROM t3);
@@ -2773,7 +2773,7 @@ SELECT * FROM t1 LEFT JOIN t2 ON (c = b)
 WHERE (a, b) IN (SELECT a, b FROM t1 t);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	idx_a	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 1	PRIMARY	t2	ref	idx_c	idx_c	4	test.t1.b	2	Using where; Using index
 2	MATERIALIZED	t	ALL	idx_a	NULL	NULL	NULL	3	
 SELECT * FROM t1 LEFT JOIN t2 ON (c = b)
@@ -2788,7 +2788,7 @@ SELECT * FROM t1 LEFT JOIN t3 ON (c = b)
 WHERE (a, b) IN (SELECT a, b FROM t1 t);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	idx_a	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 1	PRIMARY	t3	ref	idx_c	idx_c	4	test.t1.b	2	Using where
 2	MATERIALIZED	t	ALL	idx_a	NULL	NULL	NULL	3	
 SELECT * FROM t1 LEFT JOIN t3 ON (c = b)
@@ -2804,7 +2804,7 @@ SELECT * FROM t1 LEFT JOIN t2 ON (c = b)
 WHERE (a, b) IN (SELECT a, b FROM t1 t);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	idx_a	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 1	PRIMARY	t2	ref	idx_c	idx_c	4	test.t1.b	2	Using where; Using index
 2	MATERIALIZED	t	ALL	idx_a	NULL	NULL	NULL	3	
 SELECT * FROM t1 LEFT JOIN t2 ON (c = b)
@@ -2819,7 +2819,7 @@ SELECT * FROM t1 LEFT JOIN t3 ON (c = b)
 WHERE (a, b) IN (SELECT a, b FROM t1 t);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	idx_a	NULL	NULL	NULL	3	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 1	PRIMARY	t3	ref	idx_c	idx_c	4	test.t1.b	2	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
 2	MATERIALIZED	t	ALL	idx_a	NULL	NULL	NULL	3	
 SELECT * FROM t1 LEFT JOIN t3 ON (c = b)

mysql-test/r/subselect_sj_nonmerged.result

@@ -40,14 +40,14 @@ alter table t3 add primary key(a);
 #   (despite that subquery's join output estimate is 50 rows)
 explain select * from t3 where a in (select max(t2.a) from t1, t2 group by t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using where
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	8	<subquery2>.max(t2.a)	1	Using where; Using index
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 # Compare to this which really will have 50 record combinations:
 explain select * from t3 where a in (select max(t2.a) from t1, t2 group by t2.b, t1.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	50	Using where
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	50	
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	8	<subquery2>.max(t2.a)	1	Using where; Using index
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
@@ -57,7 +57,7 @@ SET optimizer_switch='outer_join_with_cache=off';
 explain select * from t3 
 where a in (select max(t2.a) from t1 left join t2 on t1.a=t2.a group by t2.b, t1.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	50	Using where
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	50	
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	8	<subquery2>.max(t2.a)	1	Using where; Using index
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using temporary
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
@@ -69,7 +69,7 @@ t4.b=t0.a and t4.a in (select max(t2.a) from t1, t2 group by t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	t4	ALL	a	NULL	NULL	NULL	100	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.t4.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	test.t4.a	1	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 insert into t4 select 100 + (B.a *100 + A.a), 100 + (B.a*100 + A.a), 'filler' from t4 A, t0 B;
@@ -77,8 +77,8 @@ explain select * from t4 where
 t4.a in (select max(t2.a) from t1, t2 group by t2.b) and 
 t4.b in (select max(t2.a) from t1, t2 group by t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using where
-1	PRIMARY	<subquery3>	ALL	distinct_key	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	
+1	PRIMARY	<subquery3>	ALL	distinct_key	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
 1	PRIMARY	t4	ref	a	a	10	<subquery2>.max(t2.a),<subquery3>.max(t2.a)	12	
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
 3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
@@ -114,7 +114,7 @@ insert into t1 select A.a + 10*B.a + 100*C.a from t0 A, t0 B, t0 C;
 # The following must use non-merged SJ-Materialization:
 explain select * from t1 X join t0 Y on X.a < Y.a where X.a in (select max(a) from t0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	1	Using where
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	1	
 1	PRIMARY	X	ref	a	a	5	<subquery2>.max(a)	1	Using index
 1	PRIMARY	Y	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
 2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	10	

mysql-test/suite/pbxt/r/group_min_max.result

@@ -2256,7 +2256,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	15	Using where
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	15	
 1	PRIMARY	t1_outer	ref	a	a	5	<subquery2>.max(b)	1	Using index
 2	MATERIALIZED	t1	index	NULL	a	10	NULL	15	Using index
 EXPLAIN SELECT 1 FROM t1 AS t1_outer GROUP BY a HAVING 

mysql-test/suite/pbxt/r/subselect.result

@@ -2842,7 +2842,7 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cac
 explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
@@ -3435,7 +3435,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	Using where
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
@@ -3447,7 +3447,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	a	NULL	NULL	NULL	9	Using where
-1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 DROP TABLE t1;
 create table t1( f1 int,f2 int);

mysql-test/t/subselect_sj_mat.test

@@ -1559,6 +1559,35 @@ WHERE a IN (
 
 DROP TABLE t1;
 
+--echo #
+--echo # BUG#939009: Crash with aggregate function in IN subquery 
+--echo #
+
+SET @save_optimizer_switch=@@optimizer_switch;
+SET optimizer_switch='materialization=on,semijoin=on';
+
+CREATE TABLE t1 (a int, b int);
+INSERT INTO t1 VALUES (7,1), (4,2), (7,7);
+
+CREATE TABLE t2 ( c INT );
+INSERT INTO t2 VALUES (4), (7), (6);
+
+EXPLAIN EXTENDED
+SELECT * FROM t1
+  WHERE a IN (SELECT MAX(c) FROM t2) AND b=7 AND (a IS NULL OR a=b);
+SELECT * FROM t1
+  WHERE a IN (SELECT MAX(c) FROM t2) AND b=7 AND (a IS NULL OR a=b);
+
+EXPLAIN
+SELECT * FROM t1
+  WHERE a IN (SELECT MAX(c) FROM t2 WHERE c < 4) AND b=7 AND (a IS NULL OR a=b);
+SELECT * FROM t1
+  WHERE a IN (SELECT MAX(c) FROM t2 WHERE c < 4) AND b=7 AND (a IS NULL OR a=b);
+
+SET optimizer_switch=@save_optimizer_switch;
+
+DROP TABLE t1,t2;
+
 --echo # This must be at the end:
 set optimizer_switch=@subselect_sj_mat_tmp;
 set join_cache_level=@save_join_cache_level;

sql/field_conv.cc

@@ -117,6 +117,11 @@ static void do_outer_field_to_null_str(Copy_field *copy)
 int
 set_field_to_null(Field *field)
 {
+  if (field->table->null_catch_flags & CHECK_ROW_FOR_NULLS_TO_REJECT)
+  {
+    field->table->null_catch_flags|= REJECT_ROW_DUE_TO_NULL_FIELDS;
+    return -1;
+  }
   if (field->real_maybe_null())
   {
     field->set_null();
@@ -160,6 +165,11 @@ set_field_to_null(Field *field)
 int
 set_field_to_null_with_conversions(Field *field, bool no_conversions)
 {
+  if (field->table->null_catch_flags & CHECK_ROW_FOR_NULLS_TO_REJECT)
+  {
+    field->table->null_catch_flags|= REJECT_ROW_DUE_TO_NULL_FIELDS;
+    return -1;
+  }
   if (field->real_maybe_null())
   {
     field->set_null();

sql/item_subselect.cc

@@ -4180,6 +4180,11 @@ bool subselect_hash_sj_engine::init(List<Item> *tmp_columns, uint subquery_id)
   memcpy(name, buf, len+1);
 
   result_sink->get_tmp_table_param()->materialized_subquery= true;
+  if (item->substype() == Item_subselect::IN_SUBS && 
+      ((Item_in_subselect*)item)->is_jtbm_merged)
+  {
+    result_sink->get_tmp_table_param()->force_not_null_cols= true;
+  }
   if (result_sink->create_result_table(thd, tmp_columns, TRUE,
                                        tmp_create_options,
 				       name, TRUE, TRUE))

sql/opt_subselect.cc

@@ -3167,6 +3167,7 @@ bool setup_sj_materialization_part1(JOIN_TAB *sjm_tab)
     sjm->sjm_table_cols.push_back(*p_item);
 
   sjm->sjm_table_param.field_count= subq_select->item_list.elements;
+  sjm->sjm_table_param.force_not_null_cols= TRUE;
 
   if (!(sjm->table= create_tmp_table(thd, &sjm->sjm_table_param, 
                                      sjm->sjm_table_cols, (ORDER*) 0, 

sql/sql_class.cc

@@ -3195,6 +3195,11 @@ int select_materialize_with_stats::send_data(List<Item> &items)
 
   if ((res= select_union::send_data(items)))
     return res;
+  if (table->null_catch_flags & REJECT_ROW_DUE_TO_NULL_FIELDS)
+  {
+    table->null_catch_flags&= ~REJECT_ROW_DUE_TO_NULL_FIELDS;
+    return 0;
+  }
   /* Skip duplicate rows. */
   if (write_err == HA_ERR_FOUND_DUPP_KEY ||
       write_err == HA_ERR_FOUND_DUPP_UNIQUE)
@@ -3236,6 +3241,7 @@ void TMP_TABLE_PARAM::init()
   precomputed_group_by= 0;
   bit_fields_as_long= 0;
   materialized_subquery= 0;
+  force_not_null_cols= 0;
   skip_create_table= 0;
   DBUG_VOID_RETURN;
 }

sql/sql_class.h

@@ -3081,6 +3081,8 @@ class TMP_TABLE_PARAM :public Sql_alloc
   bool schema_table;
   /* TRUE if the temp table is created for subquery materialization. */
   bool materialized_subquery;
+  /* TRUE if all columns of the table are guaranteed to be non-nullable */
+  bool force_not_null_cols;
   /*
     True if GROUP BY and its aggregate functions are already computed
     by a table access method (e.g. by loose index scan). In this case
@@ -3104,7 +3106,8 @@ class TMP_TABLE_PARAM :public Sql_alloc
   TMP_TABLE_PARAM()
     :copy_field(0), group_parts(0),
      group_length(0), group_null_parts(0), convert_blob_length(0),
-    schema_table(0), materialized_subquery(0), precomputed_group_by(0),
+    schema_table(0), materialized_subquery(0), force_not_null_cols(0),
+    precomputed_group_by(0),
     force_copy_fields(0), bit_fields_as_long(0), skip_create_table(0)
   {}
   ~TMP_TABLE_PARAM()

sql/sql_select.cc

@@ -3769,6 +3769,8 @@ merge_key_fields(KEY_FIELD *start,KEY_FIELD *new_fields,KEY_FIELD *end,
 	{
 	  /* field = expression OR field IS NULL */
 	  old->level= and_level;
+          if (old->field->maybe_null())
+	  {
 	    old->optimize= KEY_OPTIMIZE_REF_OR_NULL;
 	    /*
               Remember the NOT NULL value unless the value does not depend
@@ -3779,6 +3781,7 @@ merge_key_fields(KEY_FIELD *start,KEY_FIELD *new_fields,KEY_FIELD *end,
             /* The referred expression can be NULL: */ 
             old->null_rejecting= 0;
 	  }
+	}
 	else
 	{
 	  /*
@@ -13577,6 +13580,7 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
   table->merge_keys.init();
   table->intersect_keys.init();
   table->keys_in_use_for_query.init();
+  table->no_rows_with_nulls= param->force_not_null_cols;
 
   table->s= share;
   init_tmp_table_share(thd, share, "", 0, tmpname, tmpname);
@@ -13656,6 +13660,11 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
           thd->mem_root= mem_root_save;
           arg= sum_item->set_arg(i, thd, new Item_field(new_field));
           thd->mem_root= &table->mem_root;
+          if (param->force_not_null_cols)
+	  {
+            new_field->flags|= NOT_NULL_FLAG;
+            new_field->null_ptr= NULL;
+          }
 	  if (!(new_field->flags & NOT_NULL_FLAG))
           {
 	    null_count++;
@@ -13731,6 +13740,11 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
           agg_item->result_field= new_field;
       }
       tmp_from_field++;
+      if (param->force_not_null_cols)
+      {
+        new_field->flags|= NOT_NULL_FLAG;
+        new_field->null_ptr= NULL;
+      }
       reclength+=new_field->pack_length();
       if (!(new_field->flags & NOT_NULL_FLAG))
 	null_count++;

sql/sql_union.cc

@@ -57,9 +57,17 @@ int select_union::send_data(List<Item> &values)
     unit->offset_limit_cnt--;
     return 0;
   }
+  if (table->no_rows_with_nulls)
+    table->null_catch_flags= CHECK_ROW_FOR_NULLS_TO_REJECT;
   fill_record(thd, table->field, values, TRUE, FALSE);
   if (thd->is_error())
     return 1;
+  if (table->no_rows_with_nulls)
+  {
+    table->null_catch_flags&= ~CHECK_ROW_FOR_NULLS_TO_REJECT;
+    if (table->null_catch_flags)
+      return 0;
+  }
 
   if ((write_err= table->file->ha_write_tmp_row(table->record[0])))
   {

sql/table.h

@@ -665,6 +665,9 @@ enum index_hint_type
   INDEX_HINT_FORCE
 };
 
+#define      CHECK_ROW_FOR_NULLS_TO_REJECT   (1 << 0)
+#define      REJECT_ROW_DUE_TO_NULL_FIELDS   (1 << 1)
+
 struct st_table {
   st_table() {}                               /* Remove gcc warning */
 
@@ -807,6 +810,26 @@ struct st_table {
     NULL, including columns declared as "not null" (see maybe_null).
   */
   bool null_row;
+  /*
+    No rows that contain null values can be placed into this table.
+    Currently this flag can be set to true only for a temporary table
+    that used to store the result of materialization of a subquery.
+  */
+  bool no_rows_with_nulls;
+  /*
+    This field can contain two bit flags: 
+      CHECK_ROW_FOR_NULLS_TO_REJECT
+      REJECT_ROW_DUE_TO_NULL_FIELDS
+    The first flag is set for the dynamic contexts where it is prohibited
+    to write any null into the table.
+    The second flag is set only if the first flag is set on.
+    The informs the outer scope that there was an attept to write null
+    into a field of the table in the context where it is prohibited.
+    This flag should be set off as soon as the first flag is set on.
+    Currently these flags are used only the tables tno_rows_with_nulls set
+    to true. 
+  */       
+  uint8 null_catch_flags;
 
   /*
     TODO: Each of the following flags take up 8 bits. They can just as easily