MDEV-20351 Window function BIT_OR() OVER (..) return a wrong data type

mysql-test/main/win.result

@@ -3654,5 +3654,40 @@ d	x
 00:00:02	NULL
 DROP TABLE t1;
 #
+# MDEV-20351 Window function BIT_OR() OVER (..) return a wrong data type
+#
+CREATE TABLE t1 (pk INT, a INT, b BIGINT UNSIGNED);
+INSERT INTO t1 VALUES (1, 0, 1), (2, 0, 18446744073709551615);
+CREATE TABLE t2 AS
+SELECT pk, a, bit_or(b) AS bit_or FROM t1 GROUP BY pk;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `pk` int(11) DEFAULT NULL,
+  `a` int(11) DEFAULT NULL,
+  `bit_or` bigint(21) unsigned NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t1;
+pk	a	b
+1	0	1
+2	0	18446744073709551615
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 AS
+SELECT pk, a, BIT_OR(b) OVER (PARTITION BY a ORDER BY pk ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS bit_or
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `pk` int(11) DEFAULT NULL,
+  `a` int(11) DEFAULT NULL,
+  `bit_or` bigint(21) unsigned NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t2;
+pk	a	bit_or
+1	0	18446744073709551615
+2	0	18446744073709551615
+DROP TABLE t2;
+DROP TABLE t1;
+#
 # End of 10.3 tests
 #

mysql-test/main/win.test

@@ -2359,6 +2359,29 @@ INSERT INTO t1 VALUES ('00:00:01'),('00:00:02');
 SELECT *, LEAD(d) OVER (ORDER BY d) AS x FROM t1;
 DROP TABLE t1;
 
+
+--echo #
+--echo # MDEV-20351 Window function BIT_OR() OVER (..) return a wrong data type
+--echo #
+CREATE TABLE t1 (pk INT, a INT, b BIGINT UNSIGNED);
+INSERT INTO t1 VALUES (1, 0, 1), (2, 0, 18446744073709551615);
+
+CREATE TABLE t2 AS
+SELECT pk, a, bit_or(b) AS bit_or FROM t1 GROUP BY pk;
+SHOW CREATE TABLE t2;
+SELECT * FROM t1;
+DROP TABLE t2;
+
+CREATE OR REPLACE TABLE t2 AS
+SELECT pk, a, BIT_OR(b) OVER (PARTITION BY a ORDER BY pk ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS bit_or
+  FROM t1;
+SHOW CREATE TABLE t2;
+SELECT * FROM t2;
+DROP TABLE t2;
+
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 10.3 tests
 --echo #

sql/item_windowfunc.h

@@ -1282,7 +1282,7 @@ class Item_window_func : public Item_func_or_sum
 
   bool fix_length_and_dec()
   {
-    decimals = window_func()->decimals;
+    Type_std_attributes::set(window_func());
     return FALSE;
   }