Fixed LP bug #806510.

The bug was caused by an incorrect code of the function
Item_direct_view_ref::replace_equal_field introduced in the
patch for bugs 717577, 724942. The function erroneously
returned the wrapped field instead of the Item_direct_view_ref
object itself in the cases when no replacement happened.

The bug masked two other minor bugs that could result in not
quite correct output of the EXPLAIN command for some queries.
They were fixed in the patch as well.
 

1 files changed, 52 insertions, 0 deletions

diff --git a/mysql-test/r/derived_view.result b/mysql-test/r/derived_view.result
index bc8fec82275..fed5b23dc7b 100644
--- a/mysql-test/r/derived_view.result
+++ b/mysql-test/r/derived_view.result
@@ -848,3 +848,55 @@ Warnings:
 Note	1003	select `test`.`t3`.`b` AS `b`,`test`.`t1`.`a` AS `a` from `test`.`t3` left join (`test`.`t2` join `test`.`t1`) on((`test`.`t3`.`a` <> 0)) where ((`test`.`t1`.`a` = `test`.`t1`.`a`) or (`test`.`t3`.`b` <> 0))
 DROP VIEW v1;
 DROP TABLE t1,t2,t3;
+#
+# LP bug #806510: subquery with outer reference
+#                 to a derived_table/view                    
+#
+CREATE TABLE t1 (a int) ;
+INSERT INTO t1 VALUES (4), (NULL);
+CREATE TABLE t2 (a int) ;
+INSERT INTO t2 VALUES (8), (0);
+CREATE TABLE t3 (a int, b int) ;
+INSERT INTO t3 VALUES (7,8);
+CREATE VIEW v1 AS SELECT * FROM t1;
+SELECT * FROM  t1 t
+WHERE EXISTS (SELECT t3.a FROM t3, t2
+WHERE t2.a = t3.b AND t.a != 0);
+a
+4
+EXPLAIN
+SELECT * FROM  t1 t
+WHERE EXISTS (SELECT t3.a FROM t3, t2
+WHERE t2.a = t3.b AND t.a != 0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+SELECT * FROM (SELECT * FROM t1) t
+WHERE EXISTS (SELECT t3.a FROM t3, t2
+WHERE t2.a = t3.b AND t.a != 0);
+a
+4
+EXPLAIN
+SELECT * FROM (SELECT * FROM t1) t
+WHERE EXISTS (SELECT t3.a FROM t3, t2
+WHERE t2.a = t3.b AND t.a != 0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+3	DEPENDENT SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
+3	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+SELECT * FROM v1 t
+WHERE EXISTS (SELECT t3.a FROM t3, t2
+WHERE t2.a = t3.b AND t.a != 0);
+a
+4
+EXPLAIN
+SELECT * FROM v1 t
+WHERE EXISTS (SELECT t3.a FROM t3, t2
+WHERE t2.a = t3.b AND t.a != 0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+DROP VIEW v1;
+DROP TABLE t1,t2,t3;