Description:
------------
Making a variable, which was passed by reference, a reference to another variable inside the function won't work outside this function

Reproduce code:
---------------
<?php
    function &testReference(&$first, &$second) {
        $source = 'my Test';
        $first = $source;
        $second =& $source;
        var_dump($second);
        return $second;
    }
    
    $ref3 =& testReference($ref1, $ref2);
    var_dump($ref1);
    var_dump($ref2);
    var_dump($ref3);
?>

Expected result:
----------------
string(7) "my Test"
string(7) "my Test"
string(7) "my Test"
string(7) "my Test"

Actual result:
--------------
string(7) "my Test"
string(7) "my Test"
NULL
string(7) "my Test"