MDEV-16230: Server crashes when Analyze format=json is run with a window...

MDEV-16230: Server crashes when Analyze format=json is run with a window function with empty PARTITION BY and ORDER BY clauses

Currently when both PARTITION BY and ORDER BY clauses are empty then we create a Item
with the first field in the select list and sort with that field.
It should be created as an Item_temptable_field instead of Item_field because the
print() function continues to work even if the table has been dropped.

mysql-test/r/win.result

@@ -3743,5 +3743,50 @@ a	ROW_NUMBER() OVER v2
 1	1
 drop table t0;
 #
+# MDEV-16230:Server crashes when Analyze format=json is run with a window function with
+# empty PARTITION BY and ORDER BY clauses
+#
+CREATE TABLE t1(a INT, b INT);
+INSERT INTO t1 VALUES (1,1),(2,2),(3,3);
+ANALYZE FORMAT=JSON SELECT row_number() OVER() FROM t1;
+ANALYZE
+{
+  "query_block": {
+    "select_id": 1,
+    "r_loops": 1,
+    "r_total_time_ms": "REPLACED",
+    "window_functions_computation": {
+      "sorts": {
+        "filesort": {
+          "sort_key": "`row_number() OVER()`",
+          "r_loops": 1,
+          "r_total_time_ms": "REPLACED",
+          "r_used_priority_queue": false,
+          "r_output_rows": 3,
+          "r_buffer_size": "REPLACED"
+        }
+      },
+      "temporary_table": {
+        "table": {
+          "table_name": "t1",
+          "access_type": "ALL",
+          "r_loops": 1,
+          "rows": 3,
+          "r_rows": 3,
+          "r_total_time_ms": "REPLACED",
+          "filtered": 100,
+          "r_filtered": 100
+        }
+      }
+    }
+  }
+}
+SELECT row_number() OVER() FROM t1;
+row_number() OVER()
+1
+2
+3
+DROP TABLE t1;
+#
 # End of 10.2 tests
 #

mysql-test/t/win.test

@@ -2446,6 +2446,19 @@ WINDOW v2 AS ( PARTITION BY a ORDER BY a DESC );
 
 drop table t0;
 
+--echo #
+--echo # MDEV-16230:Server crashes when Analyze format=json is run with a window function with
+--echo # empty PARTITION BY and ORDER BY clauses
+--echo #
+
+CREATE TABLE t1(a INT, b INT);
+INSERT INTO t1 VALUES (1,1),(2,2),(3,3);
+
+--source include/analyze-format.inc
+ANALYZE FORMAT=JSON SELECT row_number() OVER() FROM t1;
+SELECT row_number() OVER() FROM t1;
+DROP TABLE t1;
+
 --echo #
 --echo # End of 10.2 tests
 --echo #

sql/sql_window.cc

@@ -2872,7 +2872,8 @@ bool Window_funcs_sort::setup(THD *thd, SQL_SELECT *sel,
      */
     ORDER *order= (ORDER *)alloc_root(thd->mem_root, sizeof(ORDER));
     memset(order, 0, sizeof(*order));
-    Item *item= new (thd->mem_root) Item_field(thd, join_tab->table->field[0]);
+    Item *item= new (thd->mem_root) Item_temptable_field(thd,
+                                                    join_tab->table->field[0]);
     order->item= (Item **)alloc_root(thd->mem_root, 2 * sizeof(Item *));
     order->item[1]= NULL;
     order->item[0]= item;