Description:
------------
see code

Reproduce code:
---------------
interface test
{
	public function display();
}

class A
{
	function display($sTpl)
	{
		echo $sTpl;
	}
}

class B extends A implements test
{
	private $sTpl = 'test';
	
	public function display()
	{
		$this->display($this->sTpl);
	}
}

$oB = new B();
$oB->display();

Expected result:
----------------
some error? ;)

Actual result:
--------------
Segmentation fault