MDEV-32569 Failure when executing PS for query using IN subquery

This patch corrects the fix for MDEV-32369. No Item_direct_ref_to_item
objects should be allocated at the optimizer phase after permanent
rewritings have been done.

The patch also adds another test case for MDEV-32369 that uses MyISAM
with more than one row.

Approved by Rex Johnston <rex.johnston@mariadb.com>

mysql-test/main/ps_mem_leaks.result

@@ -3,6 +3,20 @@
 #
 CREATE TABLE t1 (a VARCHAR(10)) ENGINE=MYISAM;
 CREATE TABLE t2 (b VARCHAR(10) CHARACTER SET utf8) ENGINE=MYISAM;
+INSERT INTO t1 VALUES ('b'), ('a'), ('c');
+INSERT INTO t2 VALUES ('c'), ('d'), ('b');
+PREPARE stmt FROM "SELECT t1.a FROM t1 WHERE t1.a IN (SELECT t2.b FROM t2)";
+EXECUTE stmt;
+a
+c
+b
+EXECUTE stmt;
+a
+c
+b
+DEALLOCATE PREPARE stmt;
+DELETE FROM t1;
+DELETE FROM t2;
 INSERT INTO t1 VALUES ('b');
 INSERT INTO t2 VALUES ('b');
 PREPARE stmt FROM "SELECT t1.a FROM t1 WHERE t1.a IN (SELECT t2.b FROM t2)";
@@ -14,3 +28,21 @@ a
 b
 DEALLOCATE PREPARE stmt;
 DROP TABLE t1, t2;
+#
+# MDEV-32569: Failure when executing PS for query using IN subquery
+#
+CREATE TABLE t1 (a varchar(10)) ENGINE=MYISAM;
+CREATE TABLE t2 (b varchar(10) CHARACTER SET utf8) ENGINE=MYISAM;
+INSERT INTO t1 VALUES ('b');
+INSERT INTO t2 VALUES ('b');
+PREPARE stmt FROM
+"SELECT STRAIGHT_JOIN  t1.a FROM t1 WHERE t1.a IN (SELECT t2.b FROM t2)";
+EXECUTE stmt;
+a
+b
+EXECUTE stmt;
+a
+b
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1,t2;
+# End of 10.4 tests

mysql-test/main/ps_mem_leaks.test

@@ -13,6 +13,19 @@
 CREATE TABLE t1 (a VARCHAR(10)) ENGINE=MYISAM;
 CREATE TABLE t2 (b VARCHAR(10) CHARACTER SET utf8) ENGINE=MYISAM;
 
+INSERT INTO t1 VALUES ('b'), ('a'), ('c');
+INSERT INTO t2 VALUES ('c'), ('d'), ('b');
+
+PREPARE stmt FROM "SELECT t1.a FROM t1 WHERE t1.a IN (SELECT t2.b FROM t2)";
+
+EXECUTE stmt;
+EXECUTE stmt;
+
+DEALLOCATE PREPARE stmt;
+
+DELETE FROM t1;
+DELETE FROM t2;
+
 INSERT INTO t1 VALUES ('b');
 INSERT INTO t2 VALUES ('b');
 
@@ -25,3 +38,24 @@ DEALLOCATE PREPARE stmt;
 
 DROP TABLE t1, t2;
 
+--echo #
+--echo # MDEV-32569: Failure when executing PS for query using IN subquery
+--echo #
+
+CREATE TABLE t1 (a varchar(10)) ENGINE=MYISAM;
+CREATE TABLE t2 (b varchar(10) CHARACTER SET utf8) ENGINE=MYISAM;
+
+INSERT INTO t1 VALUES ('b');
+INSERT INTO t2 VALUES ('b');
+
+PREPARE stmt FROM
+"SELECT STRAIGHT_JOIN  t1.a FROM t1 WHERE t1.a IN (SELECT t2.b FROM t2)";
+
+EXECUTE stmt;
+EXECUTE stmt;
+
+DEALLOCATE PREPARE stmt;
+
+DROP TABLE t1,t2;
+
+--echo # End of 10.4 tests

sql/item.cc

@@ -2585,7 +2585,8 @@ bool Type_std_attributes::agg_item_set_converter(const DTCollation &coll,
     if (conv->fix_fields_if_needed(thd, arg))
       return TRUE;
 
-    if (!thd->stmt_arena->is_conventional())
+    if (!thd->stmt_arena->is_conventional() &&
+        thd->lex->current_select->first_cond_optimization)
     {
       Query_arena *arena, backup;
       arena= thd->activate_stmt_arena_if_needed(&backup);