Description:
------------
When an object's method calls upon another one of its 
methods such that the second method returns a reference 
that is stored in the the first method as a local 
variable, then the reference persists in some way so as 
to make cloning problematic.

As a result, a modification to the referenced variable 
in the clone cuases a modification to the same variable 
in original.

Reproduce code:
---------------
class A
{
    var $a = array();
    
    public function makeAReference()
    {
        $array = $this->getA();
    }
    
    public function &getA()
    {
        return $this->a;
    }
}

$A = new A;
$A->a = array(1);
$A->makeAReference();
$clone = clone $A;
$clone->a = array();

print_r($A);

Expected result:
----------------
This is gotten when $A->makeAReference() is removed.

A Object
(
    [a] => Array
        (
            [0] => 1
        )

)

Actual result:
--------------
Obviously the modification made it back to the original.

A Object
(
    [a] => Array
        (
        )

)