MDEV-16751: Server crashes in st_join_table::cleanup or...

MDEV-16751: Server crashes in st_join_table::cleanup or TABLE_LIST::is_with_table_recursive_reference
            with join_cache_level>2

During muliple equality propagation for a query in which we have an IN subquery, the items in the select list of the
subquery may not be part of the multiple equality because there might be another occurence of the same field in the
where clause of the subquery.
So we keyuse_is_valid_for_access_in_chosen_plan function which expects the items in the select list of the subquery to
be same to the ones in the multiple equality (through these multiple equalities we create keyuse array).
The solution would be that we expect the same field not the same Item because when we have SEMI JOIN MATERIALIZATION SCAN,
we use copy back technique to copies back the materialised table fields to the original fields of the base tables.

mysql-test/r/subselect_mat.result

@@ -2360,6 +2360,41 @@ ec70316637232000158bbfc8bcbe5d60
 ebb4620037332000158bbfc8bcbe5d89
 DROP TABLE t1,t2,t3;
 set optimizer_switch=@save_optimizer_switch;
+#
+# MDEV-16751: Server crashes in st_join_table::cleanup or 
+# TABLE_LIST::is_with_table_recursive_reference with join_cache_level>2
+#
+set @save_join_cache_level= @@join_cache_level;
+set join_cache_level=4;
+CREATE TABLE t1 ( id int NOT NULL);
+INSERT INTO t1 VALUES (11),(12),(13),(14),(15),(16),(17),(18),(19);
+CREATE TABLE t2 (i1 int NOT NULL, i2 int NOT NULL) ;
+INSERT INTO t2 VALUES  (11,11),(12,12),(13,13);
+explain
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	
+1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	4	test.t2.i1	9	Using where; Using join buffer (flat, BNLH join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+1
+1
+1
+1
+set @@join_cache_level= @save_join_cache_level;
+alter table t1 add key(id);
+explain
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	
+1	PRIMARY	t1	ref	id	id	4	test.t2.i1	2	Using index
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+1
+1
+1
+1
+drop table t1,t2;
 # End of 5.5 tests
 set @subselect_mat_test_optimizer_switch_value=null;
 set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';

mysql-test/r/subselect_sj_mat.result

@@ -2400,4 +2400,39 @@ ec70316637232000158bbfc8bcbe5d60
 ebb4620037332000158bbfc8bcbe5d89
 DROP TABLE t1,t2,t3;
 set optimizer_switch=@save_optimizer_switch;
+#
+# MDEV-16751: Server crashes in st_join_table::cleanup or 
+# TABLE_LIST::is_with_table_recursive_reference with join_cache_level>2
+#
+set @save_join_cache_level= @@join_cache_level;
+set join_cache_level=4;
+CREATE TABLE t1 ( id int NOT NULL);
+INSERT INTO t1 VALUES (11),(12),(13),(14),(15),(16),(17),(18),(19);
+CREATE TABLE t2 (i1 int NOT NULL, i2 int NOT NULL) ;
+INSERT INTO t2 VALUES  (11,11),(12,12),(13,13);
+explain
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	
+1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	4	test.t2.i1	9	Using where; Using join buffer (flat, BNLH join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+1
+1
+1
+1
+set @@join_cache_level= @save_join_cache_level;
+alter table t1 add key(id);
+explain
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	
+1	PRIMARY	t1	ref	id	id	4	test.t2.i1	2	Using index
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+1
+1
+1
+1
+drop table t1,t2;
 # End of 5.5 tests

mysql-test/t/subselect_sj_mat.test

@@ -2151,4 +2151,29 @@ eval $q;
 DROP TABLE t1,t2,t3;
 set optimizer_switch=@save_optimizer_switch;
 
+--echo #
+--echo # MDEV-16751: Server crashes in st_join_table::cleanup or 
+--echo # TABLE_LIST::is_with_table_recursive_reference with join_cache_level>2
+--echo #
+
+set @save_join_cache_level= @@join_cache_level;
+set join_cache_level=4;
+CREATE TABLE t1 ( id int NOT NULL);
+INSERT INTO t1 VALUES (11),(12),(13),(14),(15),(16),(17),(18),(19);
+ 
+CREATE TABLE t2 (i1 int NOT NULL, i2 int NOT NULL) ;
+INSERT INTO t2 VALUES  (11,11),(12,12),(13,13);
+
+explain
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+
+set @@join_cache_level= @save_join_cache_level;
+alter table t1 add key(id);
+
+explain
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+SELECT 1 FROM t1 where t1.id IN (SELECT t2.i1 FROM t2 WHERE t2.i1 = t2.i2);
+
+drop table t1,t2;
 --echo # End of 5.5 tests

sql/opt_subselect.cc

@@ -815,6 +815,9 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
           details)
         * require that compared columns have exactly the same type. This is
           a temporary measure to avoid BUG#36752-type problems.
+
+    JOIN_TAB::keyuse_is_valid_for_access_in_chosen_plan expects that for Semi Join Materialization
+    Scan all the items in the select list of the IN Subquery are of the type Item::FIELD_ITEM.
 */
 
 static 

sql/sql_select.cc

@@ -7445,8 +7445,13 @@ bool JOIN_TAB::keyuse_is_valid_for_access_in_chosen_plan(JOIN *join,
   st_select_lex *sjm_sel= emb_sj_nest->sj_subq_pred->unit->first_select(); 
   for (uint i= 0; i < sjm_sel->item_list.elements; i++)
   {
-    if (sjm_sel->ref_pointer_array[i] == keyuse->val)
-      return true;
+    DBUG_ASSERT(sjm_sel->ref_pointer_array[i]->type() == Item::FIELD_ITEM);
+    if (keyuse->val->type() == Item::FIELD_ITEM)
+    {
+      Field *field = ((Item_field*)sjm_sel->ref_pointer_array[i])->field;
+      if (field->eq(((Item_field*)keyuse->val)->field))
+        return true;
+    }
   }
   return false; 
 }