Description:
------------
If you clone an object containing another object, the second object is actually referenced to the original. So if you change the cloned subobject, it will change the original.

Reproduce code:
---------------
class ParentObject
{
	public $value;
	public $subObject;
}

class SubObject
{
	public $value;
}

$subObject = new SubObject();
$subObject->value = 1;

$parentObject = new ParentObject();
$parentObject->value = 1;
$parentObject->subObject = clone $subObject;

$clonedObject = clone $parentObject;

$clonedObject->value = 2;
$clonedObject->subObject->value = 2;

echo $parentObject->value."\r\n";
echo $parentObject->subObject->value."\r\n";

Expected result:
----------------
1
1

Actual result:
--------------
1
2