MDEV-22461: JOIN::make_aggr_tables_info(): Assertion `select_options & (1ULL << 17)' failed.

A temporary table is needed for window function computation but if only a NAMED WINDOW SPEC
is used and there is no window function, then there is no need to create a temporary
table as there is no stage to compute WINDOW FUNCTION

mysql-test/r/win.result

@@ -3724,5 +3724,24 @@ MAX(1) OVER ()	COUNT(a)	abs(a)
 1	0	NULL
 drop table t1;
 #
+# MDEV-22461: JOIN::make_aggr_tables_info(): Assertion `select_options & (1ULL << 17)' failed.
+#
+CREATE TEMPORARY TABLE t0 (a INT PRIMARY KEY ) ;
+INSERT INTO t0 VALUES (1),(2),(3);
+SELECT a FROM t0
+WHERE a < 8
+GROUP BY 1.5
+WINDOW v2 AS ( PARTITION BY a ORDER BY a DESC );
+a
+1
+SELECT a, ROW_NUMBER() OVER v2
+FROM t0
+WHERE a < 8
+GROUP BY 1.5
+WINDOW v2 AS ( PARTITION BY a ORDER BY a DESC );
+a	ROW_NUMBER() OVER v2
+1	1
+drop table t0;
+#
 # End of 10.2 tests
 #

mysql-test/t/win.test

@@ -2426,6 +2426,26 @@ SELECT MAX(1) OVER (), COUNT(a), abs(a)  FROM t1 WHERE FALSE;
 
 drop table t1;
 
+--echo #
+--echo # MDEV-22461: JOIN::make_aggr_tables_info(): Assertion `select_options & (1ULL << 17)' failed.
+--echo #
+
+CREATE TEMPORARY TABLE t0 (a INT PRIMARY KEY ) ;
+INSERT INTO t0 VALUES (1),(2),(3);
+
+SELECT a FROM t0
+WHERE a < 8
+GROUP BY 1.5
+WINDOW v2 AS ( PARTITION BY a ORDER BY a DESC );
+
+SELECT a, ROW_NUMBER() OVER v2
+FROM t0
+WHERE a < 8
+GROUP BY 1.5
+WINDOW v2 AS ( PARTITION BY a ORDER BY a DESC );
+
+drop table t0;
+
 --echo #
 --echo # End of 10.2 tests
 --echo #

sql/sql_select.cc

@@ -2014,11 +2014,16 @@ JOIN::optimize_inner()
   }
 
   need_tmp= test_if_need_tmp_table();
-  //TODO this could probably go in test_if_need_tmp_table.
+
-  if (this->select_lex->window_specs.elements > 0) {
+  /*
-    need_tmp= TRUE;
+    If window functions are present then we can't have simple_order set to
+    TRUE as the window function needs a temp table for computation.
+    ORDER BY is computed after the window function computation is done, so
+    the sort will be done on the temp table.
+  */
+  if (select_lex->have_window_funcs())
     simple_order= FALSE;
-  }
+
 
   /*
     If the hint FORCE INDEX FOR ORDER BY/GROUP BY is used for the table

sql/sql_select.h

@@ -1636,6 +1636,7 @@ 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.
   */
@@ -1645,7 +1646,8 @@ 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,