BIT_XOR(v) OVER (...) returns wrong result

DROP DATABASE IF EXISTS bx;

CREATE DATABASE bx;

USE bx;

CREATE TABLE t (v INT);

INSERT INTO t VALUES (-5);

-- Correct scalar aggregate result

SELECT BIT_XOR(v) AS result FROM t;

-- Expected / actual:

-- 18446744073709551611

-- Incorrect window result

SELECT BIT_XOR(v) OVER () AS result FROM t;

-- Expected:

-- 18446744073709551611

-- Actual on MariaDB 12.2.2:

-- 18446744073709551615

-- Incorrect cumulative window result

SELECT BIT_XOR(v) OVER (

  ORDER BY v

  ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW

) AS result

FROM t;

-- Expected:

-- 18446744073709551611

-- Actual on MariaDB 12.2.2:

-- 18446744073709551615