Merge 10.3 into 10.4

sql/sql_select.h

@@ -1747,6 +1747,7 @@ public:
     - We are using an ORDER BY or GROUP BY on fields not in the first table
     - We are using different ORDER BY and GROUP BY orders
     - The user wants us to buffer the result.
+    - We are using WINDOW functions.
     When the WITH ROLLUP modifier is present, we cannot skip temporary table
     creation for the DISTINCT clause just because there are only const tables.
   */
@@ -1756,7 +1757,8 @@ public:
 	    ((select_distinct || !simple_order || !simple_group) ||
 	     (group_list && order) ||
              MY_TEST(select_options & OPTION_BUFFER_RESULT))) ||
-            (rollup.state != ROLLUP::STATE_NONE && select_distinct));
+            (rollup.state != ROLLUP::STATE_NONE && select_distinct) ||
+            select_lex->have_window_funcs());
   }
   bool choose_subquery_plan(table_map join_tables);
   void get_partial_cost_and_fanout(int end_tab_idx,