BUG#803457: Wrong result with semijoin + view + outer join in maria-5.3-subqueries-mwl90

(This is not a real fix for this bug, even though it makes it to no longer repeat)
- Semi-join subquery predicates, i.e. ... WHERE outer_expr IN (SELECT ...) may have null-rejecting properties,
  may allow to convert outer joins into inner.
- When convert_subq_to_sj() injected IN-equality into parent's WHERE/ON clause, it didn't call 
  $new_cond->top_level_item(), which would cause null-rejecting properties to be lost.
- Fixed, now the mentioned outer-to-inner conversion will really take place.

7 files changed, 114 insertions, 26 deletions

diff --git a/mysql-test/r/subselect_sj.result b/mysql-test/r/subselect_sj.result
index 084bc515625..31f0b19f62f 100644
--- a/mysql-test/r/subselect_sj.result
+++ b/mysql-test/r/subselect_sj.result
@@ -1,5 +1,5 @@
 drop table if exists t0, t1, t2, t3, t4, t10, t11, t12;
-drop view if exists v1, v2;
+drop view if exists v1, v2, v3, v4;
 drop procedure if exists p1;
 set @subselect_sj_tmp= @@optimizer_switch;
 set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
@@ -726,7 +726,7 @@ FROM it1 LEFT JOIN it2 ON it2.datetime_key);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	it1	index	NULL	int_key	4	NULL	2	Using index; Start temporary
 1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
-1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	20	Using where; End temporary
+1	PRIMARY	it2	ref	int_key	int_key	4	test.ot1.int_nokey	3	Using where; End temporary
 DROP TABLE ot1, it1, it2;
 # End of BUG#38075
 #
@@ -1378,7 +1378,7 @@ insert into t3 values('three'),( 'four');
 explain select * from t3 where t3.b in (select t2.b from t1 left join t2 on t1.a=t2.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	8	Using where; End temporary; Using join buffer (flat, BNL join)
 select * from t3 where t3.b in (select t2.b from t1 left join t2 on t1.a=t2.a);
 b
@@ -1593,4 +1593,34 @@ ON (t1.f3) IN ( SELECT f4 FROM t1 )
 EXECUTE st1;
 f1	f3	f4	f2	f4
 DROP TABLE t1,t2,t3;
+#
+# BUG#803457: Wrong result with semijoin + view + outer join in maria-5.3-subqueries-mwl90
+#   (Original testcase)
+#
+CREATE TABLE t1 (f1 int, f2 int );
+INSERT INTO t1 VALUES (2,0),(4,0),(0,NULL);
+CREATE TABLE t2 (f2 int, f3 int );
+INSERT INTO t2 VALUES (NULL,NULL),(0,0);
+CREATE TABLE t3 ( f1 int, f3 int );
+INSERT INTO t3 VALUES (2,0),(4,0),(0,NULL),(4,0),(8,0);
+CREATE TABLE t4 ( f2 int, KEY (f2) );
+INSERT INTO t4 VALUES (0),(NULL);
+CREATE VIEW v4 AS SELECT DISTINCT f2 FROM t4 ;
+# The following must not have outer joins:
+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	Using where
+1	PRIMARY	t4	ref	f2	f2	5	test.t2.f3	2	100.00	Using index; FirstMatch(t2)
+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 (flat, BNL join)
+Warnings:
+Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3`,`test`.`t3`.`f3` AS `f3` from `test`.`t1` semi join (`test`.`t4`) join `test`.`t2` join `test`.`t3` where ((`test`.`t1`.`f2` = `test`.`t2`.`f2`) and (`test`.`t3`.`f1` = `test`.`t1`.`f1`) and (`test`.`t4`.`f2` = `test`.`t2`.`f3`))
+SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE t2.f3 IN (SELECT * FROM t4);
+f1	f2	f3	f3
+2	0	0	0
+4	0	0	0
+4	0	0	0
+drop view v4;
+drop table t1, t2, t3, t4;
 set optimizer_switch=@subselect_sj_tmp;
diff --git a/mysql-test/r/subselect_sj2.result b/mysql-test/r/subselect_sj2.result
index e71486ab4a8..036fd6ebb48 100644
--- a/mysql-test/r/subselect_sj2.result
+++ b/mysql-test/r/subselect_sj2.result
@@ -267,10 +267,10 @@ explain select *
 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	Start temporary
-1	PRIMARY	t1	index	NULL	a	5	NULL	10	Using index; Using join buffer (flat, BNL join)
-1	PRIMARY	t2	ref	a	a	5	test.t1.a	1	Using where; Using index
-1	PRIMARY	t3	ref	a	a	5	test.t1.a	1	Using where; Using index; End temporary
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
+1	PRIMARY	t1	index	a	a	5	NULL	10	Using where; Using index
+1	PRIMARY	t2	ref	a	a	5	test.t1.a	1	Using index
+1	PRIMARY	t3	ref	a	a	5	test.t1.a	1	Using index; FirstMatch(t0)
 drop table t0, t1,t2,t3;
 CREATE TABLE t1 (
 ID int(11) NOT NULL auto_increment,
diff --git a/mysql-test/r/subselect_sj2_jcl6.result b/mysql-test/r/subselect_sj2_jcl6.result
index ef3d7700704..eefafbb1a88 100644
--- a/mysql-test/r/subselect_sj2_jcl6.result
+++ b/mysql-test/r/subselect_sj2_jcl6.result
@@ -275,10 +275,10 @@ explain select *
 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	Start temporary
-1	PRIMARY	t1	index	NULL	a	5	NULL	10	Using index; Using join buffer (flat, BNL join)
-1	PRIMARY	t2	ref	a	a	5	test.t1.a	1	Using where; Using index
-1	PRIMARY	t3	ref	a	a	5	test.t1.a	1	Using where; Using index; End temporary
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
+1	PRIMARY	t1	index	a	a	5	NULL	10	Using where; Using index
+1	PRIMARY	t2	ref	a	a	5	test.t1.a	1	Using index
+1	PRIMARY	t3	ref	a	a	5	test.t1.a	1	Using index; FirstMatch(t0)
 drop table t0, t1,t2,t3;
 CREATE TABLE t1 (
 ID int(11) NOT NULL auto_increment,
diff --git a/mysql-test/r/subselect_sj2_mat.result b/mysql-test/r/subselect_sj2_mat.result
index c680fd2ba67..5a5d0065d64 100644
--- a/mysql-test/r/subselect_sj2_mat.result
+++ b/mysql-test/r/subselect_sj2_mat.result
@@ -279,8 +279,8 @@ from t0 where a in
 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	
-2	SUBQUERY	t1	index	NULL	a	5	NULL	10	Using index
-2	SUBQUERY	t2	ref	a	a	5	test.t1.a	1	Using where; Using index
+2	SUBQUERY	t1	index	a	a	5	NULL	10	Using where; Using index
+2	SUBQUERY	t2	ref	a	a	5	test.t1.a	1	Using index
 2	SUBQUERY	t3	ref	a	a	5	test.t1.a	1	Using index
 drop table t0, t1,t2,t3;
 CREATE TABLE t1 (
diff --git a/mysql-test/r/subselect_sj_jcl6.result b/mysql-test/r/subselect_sj_jcl6.result
index b237a90f26c..382a766e7a2 100644
--- a/mysql-test/r/subselect_sj_jcl6.result
+++ b/mysql-test/r/subselect_sj_jcl6.result
@@ -9,7 +9,7 @@ show variables like 'join_cache_level';
 Variable_name	Value
 join_cache_level	6
 drop table if exists t0, t1, t2, t3, t4, t10, t11, t12;
-drop view if exists v1, v2;
+drop view if exists v1, v2, v3, v4;
 drop procedure if exists p1;
 set @subselect_sj_tmp= @@optimizer_switch;
 set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
@@ -713,22 +713,22 @@ WHERE int_nokey IN (SELECT it2.int_key
 FROM it1 LEFT JOIN it2 ON it2.datetime_key);
 int_key
 0
-2
-0
-7
+5
 9
 9
-5
+7
+2
+8
+0
 2
 0
 0
 0
-3
-7
-7
-8
 0
 5
+7
+7
+3
 EXPLAIN
 SELECT int_key FROM ot1
 WHERE int_nokey IN (SELECT it2.int_key
@@ -736,7 +736,7 @@ FROM it1 LEFT JOIN it2 ON it2.datetime_key);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	it1	index	NULL	int_key	4	NULL	2	Using index; Start temporary
 1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
-1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	20	Using where; End temporary; Using join buffer (incremental, BNL join)
+1	PRIMARY	it2	ref	int_key	int_key	4	test.ot1.int_nokey	3	Using where; End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 DROP TABLE ot1, it1, it2;
 # End of BUG#38075
 #
@@ -1467,8 +1467,8 @@ explain
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; FirstMatch(t0)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; End temporary
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 a
 1
@@ -1603,6 +1603,36 @@ ON (t1.f3) IN ( SELECT f4 FROM t1 )
 EXECUTE st1;
 f1	f3	f4	f2	f4
 DROP TABLE t1,t2,t3;
+#
+# BUG#803457: Wrong result with semijoin + view + outer join in maria-5.3-subqueries-mwl90
+#   (Original testcase)
+#
+CREATE TABLE t1 (f1 int, f2 int );
+INSERT INTO t1 VALUES (2,0),(4,0),(0,NULL);
+CREATE TABLE t2 (f2 int, f3 int );
+INSERT INTO t2 VALUES (NULL,NULL),(0,0);
+CREATE TABLE t3 ( f1 int, f3 int );
+INSERT INTO t3 VALUES (2,0),(4,0),(0,NULL),(4,0),(8,0);
+CREATE TABLE t4 ( f2 int, KEY (f2) );
+INSERT INTO t4 VALUES (0),(NULL);
+CREATE VIEW v4 AS SELECT DISTINCT f2 FROM t4 ;
+# The following must not have outer joins:
+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	Using where
+1	PRIMARY	t4	ref	f2	f2	5	test.t2.f3	2	100.00	Using index; FirstMatch(t2)
+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)
+Warnings:
+Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3`,`test`.`t3`.`f3` AS `f3` from `test`.`t1` semi join (`test`.`t4`) join `test`.`t2` join `test`.`t3` where ((`test`.`t1`.`f2` = `test`.`t2`.`f2`) and (`test`.`t3`.`f1` = `test`.`t1`.`f1`) and (`test`.`t4`.`f2` = `test`.`t2`.`f3`))
+SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE t2.f3 IN (SELECT * FROM t4);
+f1	f2	f3	f3
+2	0	0	0
+4	0	0	0
+4	0	0	0
+drop view v4;
+drop table t1, t2, t3, t4;
 set optimizer_switch=@subselect_sj_tmp;
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off
diff --git a/mysql-test/t/subselect_sj.test b/mysql-test/t/subselect_sj.test
index 2a0197a3047..4f9331be476 100644
--- a/mysql-test/t/subselect_sj.test
+++ b/mysql-test/t/subselect_sj.test
@@ -3,7 +3,7 @@
 #
 --disable_warnings
 drop table if exists t0, t1, t2, t3, t4, t10, t11, t12;
-drop view if exists v1, v2;
+drop view if exists v1, v2, v3, v4;
 drop procedure if exists p1;
 --enable_warnings
 
@@ -1459,6 +1459,32 @@ ON (t1.f3) IN ( SELECT f4 FROM t1 )
 EXECUTE st1;
 DROP TABLE t1,t2,t3;
 
+--echo #
+--echo # BUG#803457: Wrong result with semijoin + view + outer join in maria-5.3-subqueries-mwl90
+--echo #   (Original testcase)
+--echo #
+
+CREATE TABLE t1 (f1 int, f2 int );
+INSERT INTO t1 VALUES (2,0),(4,0),(0,NULL);
+
+CREATE TABLE t2 (f2 int, f3 int );
+INSERT INTO t2 VALUES (NULL,NULL),(0,0);
+
+CREATE TABLE t3 ( f1 int, f3 int );
+INSERT INTO t3 VALUES (2,0),(4,0),(0,NULL),(4,0),(8,0);
+
+CREATE TABLE t4 ( f2 int, KEY (f2) );
+INSERT INTO t4 VALUES (0),(NULL);
+
+CREATE VIEW v4 AS SELECT DISTINCT f2 FROM t4 ;
+
+--echo # The following must not have outer joins:
+explain extended
+SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE t2.f3 IN (SELECT * FROM t4); 
+SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE t2.f3 IN (SELECT * FROM t4); 
+
+drop view v4;
+drop table t1, t2, t3, t4;
 
 # The following command must be the last one the file 
 set optimizer_switch=@subselect_sj_tmp;
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc
index 9fb392c20f4..48c295b907d 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -1306,6 +1306,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
   {
     emb_tbl_nest->on_expr= and_items(emb_tbl_nest->on_expr, 
                                      sj_nest->sj_on_expr);
+    emb_tbl_nest->on_expr->top_level_item();
     if (!emb_tbl_nest->on_expr->fixed)
       emb_tbl_nest->on_expr->fix_fields(parent_join->thd,
                                         &emb_tbl_nest->on_expr);
@@ -1314,6 +1315,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
   {
     /* Inject into the WHERE */
     parent_join->conds= and_items(parent_join->conds, sj_nest->sj_on_expr);
+    parent_join->conds->top_level_item();
     /*
       fix_fields must update the properties (e.g. st_select_lex::cond_count of
       the correct select_lex.