fix for MDEV-367

The problem was that was_null and null_value variables was reset in each reexecution of IN subquery, but engine rerun only for non-constant subqueries.

Fixed checking constant in Item_equal sort.
Fix constant reporting in Item_subselect.

1 files changed, 26 insertions, 0 deletions

diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index ace1f198853..92bd97593b3 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -6132,6 +6132,32 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 SELECT MIN(a) AS min_a, a FROM t1 WHERE 1=2 HAVING a NOT IN ( SELECT a from t1 UNION select a+1 from t1 ) OR min_a != 1;
 min_a	a
 drop table t1;
+#
+# MDEV-367: Different results with and without subquery_cache on
+# a query with a constant NOT IN condition
+#
+CREATE TABLE t1 (a INT) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1),(2),(3);
+set @mdev367_optimizer_switch = @@optimizer_switch;
+set optimizer_switch = 'subquery_cache=on';
+SELECT * FROM t1 WHERE ( 3, 3 ) NOT IN ( SELECT NULL, NULL ) OR a > 100;
+a
+SELECT *, ( 3, 3 ) NOT IN ( SELECT NULL, NULL ) FROM t1;
+a	( 3, 3 ) NOT IN ( SELECT NULL, NULL )
+1	NULL
+2	NULL
+3	NULL
+set optimizer_switch=@mdev367_optimizer_switch;
+set optimizer_switch = 'subquery_cache=off';
+SELECT * FROM t1 WHERE ( 3, 3 ) NOT IN ( SELECT NULL, NULL ) OR a > 100;
+a
+SELECT *, ( 3, 3 ) NOT IN ( SELECT NULL, NULL ) FROM t1;
+a	( 3, 3 ) NOT IN ( SELECT NULL, NULL )
+1	NULL
+2	NULL
+3	NULL
+set optimizer_switch=@mdev367_optimizer_switch;
+DROP TABLE t1;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;