* @param int $field The bitmask describing the single option.
* @param int $diff The xor of the old and new bitfields.
* @param int $new The new bitfield
- * @param array $arr The array to update.
+ * @param array &$arr The array to update.
*/
protected static function checkItem( $desc, $field, $diff, $new, &$arr ) {
if ( $diff & $field ) {