Fixed the bug mdev-12931.

This corrects the patch for mdev-10006.
The current code supports only those semi-join nests that are placed at
the join top level. So such nests cannot depend on other tables or nests.

mysql-test/r/subselect_innodb.result

@@ -576,3 +576,42 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	#	
 2	DEPENDENT SUBQUERY	t2	ref	key1	key1	5	test.t1.a	#	Using where; Using filesort
 drop table t1,t2;
+#
+# mdev-12931: semi-join in ON expression of STRAIGHT_JOIN 
+#             joining a base table and a mergeable derived table
+#
+CREATE TABLE t1 (f1 int) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (3),(2);
+CREATE TABLE t2 (f2 int) ENGINE=InnoDB;
+INSERT INTO t2 VALUES (1),(4);
+CREATE TABLE t3 (f3 int) ENGINE=InnoDB;
+INSERT INTO t3 VALUES (5),(6);
+CREATE TABLE t4 (f4 int) ENGINE=InnoDB;
+INSERT INTO t4 VALUES (1),(8);
+SELECT * 
+FROM t1 
+INNER JOIN 
+( t2 STRAIGHT_JOIN ( SELECT * FROM t3 ) AS sq
+ON ( 1 IN ( SELECT f4 FROM t4 ) ) )
+ON ( f1 >= f2 );
+f1	f2	f3
+3	1	5
+2	1	5
+3	1	6
+2	1	6
+EXPLAIN EXTENDED
+SELECT * 
+FROM t1 
+INNER JOIN 
+( t2 STRAIGHT_JOIN ( SELECT * FROM t3 ) AS sq
+ON ( 1 IN ( SELECT f4 FROM t4 ) ) )
+ON ( f1 >= f2 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	100.00	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (incremental, BNL join)
+3	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t2`.`f2` AS `f2`,`test`.`t3`.`f3` AS `f3` from `test`.`t1` join `test`.`t2` semi join (`test`.`t4`) join `test`.`t3` where ((`test`.`t4`.`f4` = 1) and (`test`.`t1`.`f1` >= `test`.`t2`.`f2`))
+DROP TABLE t1,t2,t3,t4;

mysql-test/t/subselect_innodb.test

@@ -576,3 +576,38 @@ from
   t1;
 
 drop table t1,t2;
+
+--echo #
+--echo # mdev-12931: semi-join in ON expression of STRAIGHT_JOIN 
+--echo #             joining a base table and a mergeable derived table
+--echo #
+
+CREATE TABLE t1 (f1 int) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (3),(2);
+
+CREATE TABLE t2 (f2 int) ENGINE=InnoDB;
+INSERT INTO t2 VALUES (1),(4);
+
+CREATE TABLE t3 (f3 int) ENGINE=InnoDB;
+INSERT INTO t3 VALUES (5),(6);
+
+CREATE TABLE t4 (f4 int) ENGINE=InnoDB;
+INSERT INTO t4 VALUES (1),(8);
+
+SELECT * 
+FROM t1 
+     INNER JOIN 
+     ( t2 STRAIGHT_JOIN ( SELECT * FROM t3 ) AS sq
+       ON ( 1 IN ( SELECT f4 FROM t4 ) ) )
+     ON ( f1 >= f2 );
+
+EXPLAIN EXTENDED
+SELECT * 
+FROM t1 
+     INNER JOIN 
+     ( t2 STRAIGHT_JOIN ( SELECT * FROM t3 ) AS sq
+       ON ( 1 IN ( SELECT f4 FROM t4 ) ) )
+     ON ( f1 >= f2 );
+
+DROP TABLE t1,t2,t3,t4;
+

sql/sql_select.cc

@@ -14493,7 +14493,8 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top,
         table->table->maybe_null= FALSE;
       table->outer_join= 0;
       if (!(straight_join || table->straight))
-        table->dep_tables= table->embedding? table->embedding->dep_tables: 0;
+        table->dep_tables= table->embedding && !table->embedding->sj_subq_pred ?
+                             table->embedding->dep_tables : 0;
       if (table->on_expr)
       {
         /* Add ON expression to the WHERE or upper-level ON condition. */