Description:
------------
This bug report MAY be similar to:

https://bugs.php.net/bug.php?id=62616

But behave differently

Test script:
---------------
class MyFile extends SplFileObject
{
    private $x = 10;
    private $y = 20;

    public function setX($x) { $this->x = $x; }
    public function setY($y) { $this->y = $y; }

    public function getX()   { return $this->x; }
    public function count()  { return $this->y; }
}

$myFile = new MyFile(__FILE__);

var_dump($myFile->getX());
var_dump($myFile->count());

$myFile->setX(15);
$myFile->setY(25);

var_dump($myFile->getX());
var_dump($myFile->count());

$ii = new IteratorIterator($myFile);

var_dump($ii->getX());
var_dump($ii->count());

Expected result:
----------------
int(10)
int(20)
int(15)
int(25)
int(15)
int(25)

Actual result:
--------------
int(10)
int(20)
int(15)
int(25)
int(15)

Notice: Undefined property: IteratorIterator::$y in /tmp/it.php on line 12
NULL