1--TEST-- 2bug #71428: Validation type inheritance with = NULL 3--XFAIL-- 4This is a BC break 5--FILE-- 6<?php 7class A { } 8class B { public function m(A $a = NULL, $n) { echo "B.m";} }; 9class C extends B { public function m(A $a , $n) { echo "C.m";} }; 10?> 11--EXPECTF-- 12Warning: Declaration of C::m(A $a, $n) should be compatible with B::m(A $a = NULL, $n) in %sbug71428.3.php on line 4 13 14