Description:
------------
Tested on fb85d0322d39d49f37e32df6f68c9769f2cce0e4 (17.10.2014)

Code works on PHP 5.0.0 - 5.6.2 (via http://3v4l.org).

Hard to describe. Test script below is extracted from failing library test.

Clonned object affects original one by reference in magic __get() method.

Test script:
---------------
class C
{
    public $p;

    public function &__get($n)
    {
        return $this->p;
    }
}


$first = new C;
$first->p = 'init';

$clone = clone $first;
$clone->p = $first->magic;

$clone = clone $first;
$clone->p = 'foo';

var_dump($first->v);


Expected result:
----------------
string(4) "init"

Actual result:
--------------
string(3) "foo"