MDEV-3873 & MDEV-3876 & MDEV-3912 : Wrong result (extra rows) with ALL subquery

from a MERGE view.

The problem was in the lost ability to be null for the table of a left join if it
is a view/derived table.

It hapenned because setup_table_map(), was called earlier then we merged
the view or derived.

Fixed by propagating new maybe_null flag during Item::update_used_tables().

Change in join_outer.test and join_outer_jcl6.test appeared because
IS NULL reported no used tables (i.e. constant) for argument which could not be
NULL and new maybe_null flag was propagated for IS NULL argument (Item_field)
because table the Item_field belonged to changed its maybe_null status.

1 files changed, 4 insertions, 4 deletions

diff --git a/mysql-test/r/join_outer.result b/mysql-test/r/join_outer.result
index 17bc705b4f3..4541cdbc752 100644
--- a/mysql-test/r/join_outer.result
+++ b/mysql-test/r/join_outer.result
@@ -1770,10 +1770,10 @@ SELECT t1.pk FROM t2 LEFT JOIN t1 ON t2.pk = t1.a
 WHERE t1.b BETWEEN 5 AND 6 AND t1.pk IS NULL OR t1.pk = 5
 ORDER BY t1.pk;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	const	PRIMARY,idx	PRIMARY	4	const	1	100.00	
+1	SIMPLE	t1	const	PRIMARY	PRIMARY	4	const	1	100.00	
 1	SIMPLE	t2	const	PRIMARY	PRIMARY	4	const	1	100.00	Using index
 Warnings:
-Note	1003	select 5 AS `pk` from `test`.`t2` join `test`.`t1` where ((((1 between 5 and 6) and isnull(5)) or 1)) order by 5
+Note	1003	select 5 AS `pk` from `test`.`t2` join `test`.`t1` where (1) order by 5
 SELECT t1.pk FROM t2 LEFT JOIN t1 ON t2.pk = t1.a
 WHERE t1.b BETWEEN 5 AND 6 AND t1.pk IS NULL OR t1.pk = 5
 ORDER BY t1.pk;
@@ -1809,10 +1809,10 @@ SELECT t1.b, t2.c, t2.d FROM t2 LEFT JOIN t1 ON t2.c = t1.a
 WHERE t1.pk BETWEEN 5 AND 6 AND t1.b IS NULL OR t1.b = 5
 ORDER BY t1.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	ref	PRIMARY,idx	idx	4	const	2	100.00	Using where; Using filesort
+1	SIMPLE	t1	ref	idx	idx	4	const	2	100.00	Using where
 1	SIMPLE	t2	ref	c	c	5	test.t1.a	2	100.00	
 Warnings:
-Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c`,`test`.`t2`.`d` AS `d` from `test`.`t2` join `test`.`t1` where ((`test`.`t2`.`c` = `test`.`t1`.`a`) and (((`test`.`t1`.`pk` between 5 and 6) and isnull(`test`.`t1`.`b`)) or (`test`.`t1`.`b` = 5))) order by `test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c`,`test`.`t2`.`d` AS `d` from `test`.`t2` join `test`.`t1` where ((`test`.`t2`.`c` = `test`.`t1`.`a`) and (`test`.`t1`.`b` = 5)) order by `test`.`t1`.`b`
 SELECT t1.b, t2.c, t2.d FROM t2 LEFT JOIN t1 ON t2.c = t1.a
 WHERE t1.pk BETWEEN 5 AND 6 AND t1.b IS NULL OR t1.b = 5
 ORDER BY t1.b;