MDEV-13068 Crash in Item::split_sum_func2 with INSERT SELECT using window functions

When running setup fields during the final step of insert using select
the final setup_fields does not have any sum functions. Our current
condition for calling split_sum_func however would attempt to use an empty
NULL sum_func_list, if the item contained a window function.

The solution is to not perform another split_sum_func for the item
containing a window function if we do not actually have a sum_func_list.

mysql-test/r/win_insert_select.result

+CREATE TABLE t1 (c1 INT, c2 VARCHAR(30));
+PREPARE populate_table FROM "INSERT into t1 values (1, 'manual_insert_1'),
+                                                   (4, 'manual_insert_2')";
+INSERT INTO t1 SELECT row_number() over(), "should_have_0" FROM t1;
+INSERT INTO t1 SELECT 1 + row_number() over(), "should_have_2" FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1 SELECT 10 + row_number() over(), "should repeat 4 times [11-14]" FROM t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+1	manual_insert_1
+4	manual_insert_2
+11	should repeat 4 times [11-14]
+12	should repeat 4 times [11-14]
+13	should repeat 4 times [11-14]
+14	should repeat 4 times [11-14]
+0	should_have_0
+2	should_have_2
+DELETE FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1
+SELECT 10 + (dense_rank() over(order by c1)), "dense_rank_insert" from t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+11	dense_rank_insert
+12	dense_rank_insert
+1	manual_insert_1
+4	manual_insert_2
+DELETE FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1
+SELECT 100 + (rank() over(order by c1)), "rank_insert" from t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+1	manual_insert_1
+4	manual_insert_2
+101	rank_insert
+102	rank_insert
+DELETE FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1
+SELECT 100 + (ntile(10) over(order by c1)), "ntile_insert" from t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+1	manual_insert_1
+4	manual_insert_2
+101	ntile_insert
+102	ntile_insert
+DELETE FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1
+SELECT 1000 + (percent_rank() over(order by c1)), "percent_rank_insert" from t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+1	manual_insert_1
+4	manual_insert_2
+1000	percent_rank_insert
+1001	percent_rank_insert
+DELETE FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1
+SELECT 1000 + (count(*) over(order by c1)), "count_insert" from t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+1001	count_insert
+1002	count_insert
+1	manual_insert_1
+4	manual_insert_2
+DELETE FROM t1;
+EXECUTE populate_table;
+#
+# Test how avg interacts when the results need to be rounded.
+#
+SELECT 1000 + (avg(c1) over(order by c1)) as avg_expr, c1, "This will be inserted into t1" from t1;
+avg_expr	c1	This will be inserted into t1
+1001.0000	1	This will be inserted into t1
+1002.5000	4	This will be inserted into t1
+INSERT INTO t1
+SELECT 1000 + (avg(c1) over(order by c1)), "avg_insert" from t1;
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+c1	c2
+1001	avg_insert
+1003	avg_insert
+1	manual_insert_1
+4	manual_insert_2
+DELETE FROM t1;
+EXECUTE populate_table;
+INSERT INTO t1
+SELECT 1000 + (sum(c1) over(order by c1)), "sum_insert" from t1;
+SELECT c1, c2
+FROM t1
+ORDER BY c2, c1;
+c1	c2
+1	manual_insert_1
+4	manual_insert_2
+1001	sum_insert
+1005	sum_insert
+DROP table t1;

mysql-test/t/win_insert_select.test

+CREATE TABLE t1 (c1 INT, c2 VARCHAR(30));
+
+PREPARE populate_table FROM "INSERT into t1 values (1, 'manual_insert_1'),
+                                                   (4, 'manual_insert_2')";
+
+INSERT INTO t1 SELECT row_number() over(), "should_have_0" FROM t1;
+INSERT INTO t1 SELECT 1 + row_number() over(), "should_have_2" FROM t1;
+
+EXECUTE populate_table;
+
+INSERT INTO t1 SELECT 10 + row_number() over(), "should repeat 4 times [11-14]" FROM t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+
+INSERT INTO t1
+    SELECT 10 + (dense_rank() over(order by c1)), "dense_rank_insert" from t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+INSERT INTO t1
+    SELECT 100 + (rank() over(order by c1)), "rank_insert" from t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+INSERT INTO t1
+    SELECT 100 + (ntile(10) over(order by c1)), "ntile_insert" from t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+INSERT INTO t1
+    SELECT 1000 + (percent_rank() over(order by c1)), "percent_rank_insert" from t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+INSERT INTO t1
+    SELECT 1000 + (count(*) over(order by c1)), "count_insert" from t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+--echo #
+--echo # Test how avg interacts when the results need to be rounded.
+--echo #
+SELECT 1000 + (avg(c1) over(order by c1)) as avg_expr, c1, "This will be inserted into t1" from t1;
+
+INSERT INTO t1
+    SELECT 1000 + (avg(c1) over(order by c1)), "avg_insert" from t1;
+
+SELECT c1, c2 FROM t1 ORDER BY c2, c1;
+
+DELETE FROM t1;
+EXECUTE populate_table;
+
+INSERT INTO t1
+    SELECT 1000 + (sum(c1) over(order by c1)), "sum_insert" from t1;
+
+SELECT c1, c2
+FROM t1
+ORDER BY c2, c1;
+
+DROP table t1;

sql/sql_base.cc

@@ -7068,10 +7068,13 @@ bool setup_fields(THD *thd, Ref_ptr_array ref_pointer_array,
       split_sum_func() must be called for Window Function items, see
       Item_window_func::split_sum_func.
     */
-    if ((item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM &&
-	 sum_func_list) || item->with_window_func)
+    if (sum_func_list &&
+         ((item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM) ||
+          item->with_window_func))
+    {
       item->split_sum_func(thd, ref_pointer_array, *sum_func_list,
                            SPLIT_SUM_SELECT);
+    }
     thd->lex->current_select->select_list_tables|= item->used_tables();
     thd->lex->used_tables|= item->used_tables();
     thd->lex->current_select->cur_pos_in_select_list++;