Description:
------------
In the code below method StructAddNodePointer gets a part (branch) of the array (in the example $bar->dxml_struct_arr) and fills it. It works in PHP 5.0.5 but doesn't work in PHP 5.1.1. It seems in PHP 5.1.1 passing &$dxml_struct_arr by reference doesn't work. Or may be it doesn't work here: $pointer_tree_doc_value = &$bar->StructAddNodePointer('doc', $bar->dxml_struct_arr);

Reproduce code:
---------------
class foo {
	function StructAddNode($tag, &$dxml_struct_arr, $attribs = array()) {
		$dxml_struct_arr[] = array(
			'tag' => $tag,
			'value' => null #array()
		);
		$index= (sizeof($dxml_struct_arr)-1);
		return $index;
	}
	function StructAddNodePointer($tag, &$dxml_struct_arr, $attribs = array()) {
		$index = $this->StructAddNode($tag, $dxml_struct_arr, $attribs);
		return $dxml_struct_arr[$index]['value'];
	}
}
$bar = new foo();
$bar->dxml_struct_arr = array();
$pointer_tree_doc_value = &$bar->StructAddNodePointer('doc', $bar->dxml_struct_arr);
$pointer_tree_head_value = &$bar->StructAddNodePointer('HEAD', $pointer_tree_doc_value);
print_r($bar->dxml_struct_arr);

Expected result:
----------------
Array
(
    [0] => Array
        (
            [tag] => doc
            [value] => Array
                (
                    [0] => Array
                        (
                            [tag] => HEAD
                            [value] => 
                        )

                )

        )

)


Actual result:
--------------
Array
(
    [0] => Array
        (
            [tag] => doc
            [value] => 
        )

)