MDEV-10389: Query returns different results on a debug vs non-debug build

The problem was caused by a merged semi-join, which contained a non-merged
semi-join, which used references to the top-level query in the left_expr.

When moving non-merged semi-join from the subquery to its parent, do not
forget to call fix_after_pullout for its Item_subselect. We need to do
that specifically, because non-merged semi-joins do not have their
IN-equality in the WHERE clause at this stage.

mysql-test/r/subselect_mat.result

@@ -2261,6 +2261,19 @@ PREPARE stmt FROM '
 EXECUTE stmt;
 EXECUTE stmt;
 DROP TABLE t1,t2,t3;
+#
+# MDEV-10389: Query returns different results on a debug vs non-debug build of the same revision
+#
+CREATE TABLE t1 (i1 INT, i2 INT NOT NULL);
+INSERT INTO t1 VALUES (1,4),(2,6);
+SELECT * FROM t1 AS alias1
+WHERE alias1.i1 IN (
+SELECT i1 FROM t1 WHERE alias1.i2 IN ( SELECT i2 FROM t1 HAVING i2 <> 7 )
+);
+i1	i2
+1	4
+2	6
+DROP TABLE t1;
 set @subselect_mat_test_optimizer_switch_value=null;
 set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
 set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';

mysql-test/r/subselect_sj_mat.result

@@ -2301,3 +2301,16 @@ PREPARE stmt FROM '
 EXECUTE stmt;
 EXECUTE stmt;
 DROP TABLE t1,t2,t3;
+#
+# MDEV-10389: Query returns different results on a debug vs non-debug build of the same revision
+#
+CREATE TABLE t1 (i1 INT, i2 INT NOT NULL);
+INSERT INTO t1 VALUES (1,4),(2,6);
+SELECT * FROM t1 AS alias1
+WHERE alias1.i1 IN (
+SELECT i1 FROM t1 WHERE alias1.i2 IN ( SELECT i2 FROM t1 HAVING i2 <> 7 )
+);
+i1	i2
+1	4
+2	6
+DROP TABLE t1;

mysql-test/t/subselect_sj_mat.test

@@ -1925,3 +1925,15 @@ EXECUTE stmt;
 
 DROP TABLE t1,t2,t3;
 
+--echo #
+--echo # MDEV-10389: Query returns different results on a debug vs non-debug build of the same revision
+--echo #
+CREATE TABLE t1 (i1 INT, i2 INT NOT NULL);
+INSERT INTO t1 VALUES (1,4),(2,6);
+
+SELECT * FROM t1 AS alias1
+WHERE alias1.i1 IN (
+    SELECT i1 FROM t1 WHERE alias1.i2 IN ( SELECT i2 FROM t1 HAVING i2 <> 7 )
+);
+DROP TABLE t1;
+

sql/opt_subselect.cc

@@ -1558,7 +1558,12 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
   {
     tl->set_tablenr(table_no);
     if (tl->is_jtbm())
+    {
       tl->jtbm_table_no= table_no;
+      Item *dummy= tl->jtbm_subselect;
+      tl->jtbm_subselect->fix_after_pullout(parent_lex, &dummy);
+      DBUG_ASSERT(dummy == tl->jtbm_subselect);
+    }
     SELECT_LEX *old_sl= tl->select_lex;
     tl->select_lex= parent_join->select_lex; 
     for (TABLE_LIST *emb= tl->embedding;