Description:
------------
A global variable which references a session variable 
inside a class loses its global scope. 

Reproduce code:
---------------
<?php
session_start();

class test {
  function test() {
    global $b;

    if (!isset($_SESSION['a'])) {
      $_SESSION['a'] = 0;
    }

    $b =& $_SESSION['a'];
  }
}

$test = new test;

$b++;

echo $b;

echo '<br><br>';

echo '<a href="' . basename($_SERVER['PHP_SELF']) . ((defined('SID') && strlen(SID) > 0) ? '?' . SID : '') . '">reload</a>';
?>

Expected result:
----------------
The counter shown should be incremented on each page 
reload. 

Actual result:
--------------
The counter does not get incremented and stays at 1. 
 
Changing the following line: 
 
$b =& $_SESSION['a']; 
 
to: 
 
$GLOBALS['b'] =& $_SESSION['a']; 
 
produces the expected result.