MDEV-23384 Server crashes in subselect_indexsubquery_engine::print with optimizer trace enabled

	unitialized data structures
	causing subselect_indexsubquery_engine::print
	and subselect_uniquesubquery_engine::print to crash
	when optimizer_trace is enabled

mysql-test/main/opt_trace.result

@@ -8522,5 +8522,52 @@ SELECT a FROM t1 WHERE (a,b) in (SELECT @c,@d);
 a
 DROP TABLE t1;
 #
+# MDEV-23384: Server crashes in subselect_indexsubquery_engine::print with optimizer trace enabled
+#
+# test subselect_indexsubquery_engine::print
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (3),(4);
+CREATE TABLE t3 (c INT);
+CREATE TABLE t4 (d INT);
+INSERT INTO t4 VALUES (5),(6);
+SET SESSION optimizer_trace= 'enabled=on';
+UPDATE t1, t2 SET t2.b = 1 WHERE
+(
+WITH cte1 AS 
+(
+SELECT MAX(c) FROM t3 WHERE c = 0 OR c IN 
+(
+WITH cte2 AS 
+(
+SELECT d FROM t4
+) 
+SELECT * FROM cte2
+)
+)
+SELECT * FROM cte1
+) IS NULL;
+# test subselect_uniquesubquery_engine::print
+CREATE TABLE t10 (a int, b int) ENGINE=myisam;
+CREATE TABLE t11 (a int, b int, unique(a));
+INSERT INTO t11 SELECT seq, seq FROM seq_1_to_10;
+CREATE TABLE t12 (a int, key(a));
+INSERT INTO t12 SELECT seq FROM seq_1_to_1000;
+SET SESSION optimizer_trace= 'enabled=on';
+SELECT * FROM t12 WHERE t12.a <
+(
+SELECT b FROM
+(
+SELECT b FROM t10 WHERE a <3 or a in
+(
+SELECT a FROM t11 WHERE t11.b<t10.b
+)
+LIMIT 2
+) T
+);
+a
+DROP TABLE t1, t2, t3, t4, t10, t11, t12;
+#
 # End of 10.4 tests
 #

mysql-test/main/opt_trace.test

@@ -677,6 +677,70 @@ INSERT INTO t1 VALUES (0,0);
 SELECT a FROM t1 WHERE (a,b) in (SELECT @c,@d);
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-23384: Server crashes in subselect_indexsubquery_engine::print with optimizer trace enabled
+--echo #
+--echo # test subselect_indexsubquery_engine::print
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2);
+ 
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (3),(4);
+ 
+CREATE TABLE t3 (c INT);
+ 
+CREATE TABLE t4 (d INT);
+INSERT INTO t4 VALUES (5),(6);
+ 
+SET SESSION optimizer_trace= 'enabled=on';
+ 
+UPDATE t1, t2 SET t2.b = 1 WHERE
+(
+  WITH cte1 AS 
+  (
+    SELECT MAX(c) FROM t3 WHERE c = 0 OR c IN 
+    (
+      WITH cte2 AS 
+      (
+        SELECT d FROM t4
+      ) 
+      SELECT * FROM cte2
+    )
+  )
+  SELECT * FROM cte1
+) IS NULL;
+
+# we don't actually need the trace, we are testing for a crash
+--echo # test subselect_uniquesubquery_engine::print
+
+CREATE TABLE t10 (a int, b int) ENGINE=myisam;
+
+CREATE TABLE t11 (a int, b int, unique(a));
+
+INSERT INTO t11 SELECT seq, seq FROM seq_1_to_10;
+
+CREATE TABLE t12 (a int, key(a));
+
+INSERT INTO t12 SELECT seq FROM seq_1_to_1000;
+
+SET SESSION optimizer_trace= 'enabled=on';
+
+SELECT * FROM t12 WHERE t12.a <
+(
+  SELECT b FROM
+  (
+    SELECT b FROM t10 WHERE a <3 or a in
+    (
+      SELECT a FROM t11 WHERE t11.b<t10.b
+    )
+    LIMIT 2
+  ) T
+);
+
+# Cleanup
+DROP TABLE t1, t2, t3, t4, t10, t11, t12;
+
 --echo #
 --echo # End of 10.4 tests
 --echo #

sql/item_subselect.cc

@@ -4537,7 +4537,7 @@ void subselect_uniquesubquery_engine::print(String *str,
   str->append(STRING_WITH_LEN("<primary_index_lookup>("));
   tab->ref.items[0]->print(str, query_type);
   str->append(STRING_WITH_LEN(" in "));
-  if (tab->table->s->table_category == TABLE_CATEGORY_TEMPORARY)
+  if (tab->tab_list->table->s->table_category == TABLE_CATEGORY_TEMPORARY)
   {
     /*
       Temporary tables' names change across runs, so they can't be used for
@@ -4546,8 +4546,8 @@ void subselect_uniquesubquery_engine::print(String *str,
     str->append(STRING_WITH_LEN("<temporary table>"));
   }
   else
-    str->append(&tab->table->s->table_name);
-  KEY *key_info= tab->table->key_info+ tab->ref.key;
+    str->append(&tab->tab_list->table->s->table_name);
+  KEY *key_info= tab->tab_list->table->key_info+ tab->ref.key;
   str->append(STRING_WITH_LEN(" on "));
   str->append(&key_info->name);
   if (cond)
@@ -4588,8 +4588,9 @@ void subselect_indexsubquery_engine::print(String *str,
   str->append(STRING_WITH_LEN("<index_lookup>("));
   tab->ref.items[0]->print(str, query_type);
   str->append(STRING_WITH_LEN(" in "));
-  str->append(tab->table->s->table_name.str, tab->table->s->table_name.length);
-  KEY *key_info= tab->table->key_info+ tab->ref.key;
+  str->append(tab->tab_list->table->s->table_name.str,
+              tab->tab_list->table->s->table_name.length);
+  KEY *key_info= tab->tab_list->table->key_info+ tab->ref.key;
   str->append(STRING_WITH_LEN(" on "));
   str->append(&key_info->name);
   if (check_null)
@@ -5264,11 +5265,15 @@ subselect_hash_sj_engine::make_unique_engine()
     - this JOIN_TAB has no corresponding JOIN (and doesn't need one), and
     - here we initialize only those members that are used by
       subselect_uniquesubquery_engine, so these objects are incomplete.
+    tab->tab_list is used in ::print, it needs initialization too.
   */
-  if (!(tab= (JOIN_TAB*) thd->alloc(sizeof(JOIN_TAB))))
+  if (!(tab= (JOIN_TAB*) thd->calloc(sizeof(JOIN_TAB))))
+    DBUG_RETURN(NULL);
+
+  if (!(tab->tab_list= (TABLE_LIST *)thd->calloc(sizeof(TABLE_LIST))))
     DBUG_RETURN(NULL);
 
-  tab->table= tmp_table;
+  tab->table= tab->tab_list->table= tmp_table;
   tab->preread_init_done= FALSE;
   tab->ref.tmp_table_index_lookup_init(thd, tmp_key, it, FALSE);