Commit d649efbb authored by unknown's avatar unknown
Browse files

Fixed bug #23478. 

If elements a not top-level IN subquery were accessed by an index and 
the subquery result set included  a NULL value then the quantified
predicate that contained the subquery was evaluated to NULL when 
it should return a non-null value.


mysql-test/r/subselect.result:
  Added a test case for bug #23478.
mysql-test/t/subselect.test:
  Added a test case for bug #23478.
parent 9bfaab57

mysql-test/r/subselect.result

+15 −0
Original line number Diff line number Diff line
@@ -2982,3 +2982,18 @@ field1 field2 
1	1

1	3

DROP TABLE t1, t2;

CREATE TABLE t1(a int, INDEX (a));

INSERT INTO t1 VALUES (1), (3), (5), (7);

INSERT INTO t1 VALUES (NULL);

CREATE TABLE t2(a int);

INSERT INTO t2 VALUES (1),(2),(3);

EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	

2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index

SELECT a, a IN (SELECT a FROM t1) FROM t2;

a	a IN (SELECT a FROM t1)

1	1

2	NULL

3	1

DROP TABLE t1,t2;

mysql-test/t/subselect.test

+17 −0
Original line number Diff line number Diff line
@@ -1948,4 +1948,21 @@ SELECT field1, field2 


DROP TABLE t1, t2;



#

# Bug #23478: not top-level IN subquery returning a non-empty result set

#             with possible NULL values by index access from the outer query

#



CREATE TABLE t1(a int, INDEX (a));

INSERT INTO t1 VALUES (1), (3), (5), (7);

INSERT INTO t1 VALUES (NULL);



CREATE TABLE t2(a int);

INSERT INTO t2 VALUES (1),(2),(3);



EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;

SELECT a, a IN (SELECT a FROM t1) FROM t2;



DROP TABLE t1,t2;



# End of 4.1 tests

sql/item_subselect.cc

+3 −0
Original line number Diff line number Diff line
@@ -610,6 +610,7 @@ double Item_in_subselect::val() 
  */

  DBUG_ASSERT(0);

  DBUG_ASSERT(fixed == 1);

  null_value= 0;

  if (exec())

  {

    reset();
@@ -625,6 +626,7 @@ double Item_in_subselect::val() 
longlong Item_in_subselect::val_int()

{

  DBUG_ASSERT(fixed == 1);

  null_value= 0;

  if (exec())

  {

    reset();
@@ -645,6 +647,7 @@ String *Item_in_subselect::val_str(String *str) 
  */

  DBUG_ASSERT(0);

  DBUG_ASSERT(fixed == 1);

  null_value= 0;

  if (exec())

  {

    reset();