Merge branch '10.2' into 10.3

1 files changed, 7 insertions, 1 deletions

diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc
index eff28d0c27d..a723980ad50 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -848,8 +848,10 @@ bool subquery_types_allow_materialization(Item_in_subselect *in_subs)
      Make sure that create_tmp_table will not fail due to too long keys.
      See MDEV-7122. This check is performed inside create_tmp_table also and
      we must do it so that we know the table has keys created.
+     Make sure that the length of the key for the temp_table is atleast
+     greater than 0.
   */
-  if (total_key_length > tmp_table_max_key_length() ||
+  if (!total_key_length || total_key_length > tmp_table_max_key_length() ||
       elements > tmp_table_max_key_parts())
     DBUG_RETURN(FALSE);
 
@@ -979,6 +981,10 @@ bool check_for_outer_joins(List<TABLE_LIST> *join_list)
 void find_and_block_conversion_to_sj(Item *to_find,
 				     List_iterator_fast<Item_in_subselect> &li)
 {
+  if (to_find->type() == Item::FUNC_ITEM &&
+     ((Item_func*)to_find)->functype() == Item_func::IN_OPTIMIZER_FUNC)
+    to_find= ((Item_in_optimizer*)to_find)->get_wrapped_in_subselect_item();
+
   if (to_find->type() != Item::SUBSELECT_ITEM ||
       ((Item_subselect *) to_find)->substype() != Item_subselect::IN_SUBS)
     return;