BUG#784723: Wrong result with semijoin + nested subqueries in maria-5.3

- in advance_sj_state(), remember join->cur_dups_producing_tables in 
  pos->prefix_dups_producing_tables *before* we modify it, so that 
  restore_prev_sj_state() restores cur_dups_producing_tables in all cases.
- Updated test results in subselect_sj2[_jcl6].result (the original EXPLAIN
  was invalid there)

mysql-test/r/subselect_sj.result

@@ -1240,4 +1240,31 @@ IN (SELECT t3.pk, t3.pk FROM t2 LEFT JOIN t3 ON t3.varchar_key)
 AND pk = 9;
 datetime_key
 DROP TABLE t1, t2, t3;
+#
+# BUG#784723: Wrong result with semijoin + nested subqueries in maria-5.3  
+#
+CREATE TABLE t1 ( t1field integer, primary key (t1field));
+CREATE TABLE t2 ( t2field integer, primary key (t2field));
+INSERT INTO t1 VALUES (1),(2),(3);
+INSERT INTO t2 VALUES (2),(3),(4);
+explain 
+SELECT * FROM t1 A 
+WHERE 
+A.t1field IN (SELECT A.t1field FROM t2 B) AND 
+A.t1field IN (SELECT C.t2field FROM t2 C 
+WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index; Start temporary
+1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	C	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
+1	PRIMARY	D	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
+SELECT * FROM t1 A 
+WHERE 
+A.t1field IN (SELECT A.t1field FROM t2 B) AND 
+A.t1field IN (SELECT C.t2field FROM t2 C 
+WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
+t1field
+2
+3
+drop table t1,t2;
 set @@optimizer_switch=@save_optimizer_switch;

mysql-test/r/subselect_sj2.result

@@ -311,9 +311,10 @@ t2.Code IN (SELECT Country FROM t3
 WHERE Language='English' AND Percentage > 10 AND
 t2.Population > 100000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	Population,Country	Population	4	NULL	1	Using index condition; Rowid-ordered scan
-1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where
+1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	1	
 1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t1.Country	1	Using where
+1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where
+2	SUBQUERY	t1	range	Population,Country	Population	4	NULL	1	Using index condition; Rowid-ordered scan
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (
 Code char(3) NOT NULL DEFAULT '',

mysql-test/r/subselect_sj2_jcl6.result

@@ -318,9 +318,10 @@ t2.Code IN (SELECT Country FROM t3
 WHERE Language='English' AND Percentage > 10 AND
 t2.Population > 100000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	Population,Country	Population	4	NULL	1	Using index condition; Rowid-ordered scan
-1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t1.Country	1	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	1	
+1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t1.Country	1	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
+2	SUBQUERY	t1	range	Population,Country	Population	4	NULL	1	Using index condition; Rowid-ordered scan
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (
 Code char(3) NOT NULL DEFAULT '',

mysql-test/r/subselect_sj_jcl6.result

@@ -1248,6 +1248,33 @@ IN (SELECT t3.pk, t3.pk FROM t2 LEFT JOIN t3 ON t3.varchar_key)
 AND pk = 9;
 datetime_key
 DROP TABLE t1, t2, t3;
+#
+# BUG#784723: Wrong result with semijoin + nested subqueries in maria-5.3  
+#
+CREATE TABLE t1 ( t1field integer, primary key (t1field));
+CREATE TABLE t2 ( t2field integer, primary key (t2field));
+INSERT INTO t1 VALUES (1),(2),(3);
+INSERT INTO t2 VALUES (2),(3),(4);
+explain 
+SELECT * FROM t1 A 
+WHERE 
+A.t1field IN (SELECT A.t1field FROM t2 B) AND 
+A.t1field IN (SELECT C.t2field FROM t2 C 
+WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index; Start temporary
+1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	C	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
+1	PRIMARY	D	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
+SELECT * FROM t1 A 
+WHERE 
+A.t1field IN (SELECT A.t1field FROM t2 B) AND 
+A.t1field IN (SELECT C.t2field FROM t2 C 
+WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
+t1field
+2
+3
+drop table t1,t2;
 set @@optimizer_switch=@save_optimizer_switch;
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off

mysql-test/t/subselect_sj.test

@@ -1117,6 +1117,25 @@ WHERE (int_nokey, pk)
 
 DROP TABLE t1, t2, t3;
 
+--echo #
+--echo # BUG#784723: Wrong result with semijoin + nested subqueries in maria-5.3  
+--echo #
+CREATE TABLE t1 ( t1field integer, primary key (t1field));
+CREATE TABLE t2 ( t2field integer, primary key (t2field));
+INSERT INTO t1 VALUES (1),(2),(3);
+INSERT INTO t2 VALUES (2),(3),(4);
+explain 
+SELECT * FROM t1 A 
+WHERE 
+  A.t1field IN (SELECT A.t1field FROM t2 B) AND 
+  A.t1field IN (SELECT C.t2field FROM t2 C 
+                WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
+SELECT * FROM t1 A 
+WHERE 
+  A.t1field IN (SELECT A.t1field FROM t2 B) AND 
+  A.t1field IN (SELECT C.t2field FROM t2 C 
+                WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
+drop table t1,t2;
 
 # The following command must be the last one the file 
 set @@optimizer_switch=@save_optimizer_switch;

sql/opt_subselect.cc

@@ -1429,6 +1429,7 @@ void advance_sj_state(JOIN *join, table_map remaining_tables,
   pos->prefix_record_count= *current_record_count;
   pos->sj_strategy= SJ_OPT_NONE;
   
+  pos->prefix_dups_producing_tables= join->cur_dups_producing_tables;
   /* Initialize the state or copy it from prev. tables */
   if (idx == join->const_tables)
   {
@@ -1861,7 +1862,6 @@ void advance_sj_state(JOIN *join, table_map remaining_tables,
       }
     }
   }
-  pos->prefix_dups_producing_tables= join->cur_dups_producing_tables;
 }