Description:
------------
When a class is instantiated globally, and assigned to a variable name which is the same as a session variable, then the session variable get overwritten with the class.

This may happen with non-class variables, but I am not sure.




Reproduce code:
---------------
changing $entrain to anything else (i.e. $entra) fixes the problem.

<?php
session_start();

$entrain = new entrainRuntime();

var_dump($_SESSION);

class entrainRuntime
{
    function entrainRuntime ()
    {
	    $_SESSION['entrain'] = array();
    }
}

?>

Expected result:
----------------
array(1) {"entrain" => array(0) {}}

this happens the first time, expected



Actual result:
--------------
On subsequent refreshes:

array(1) {"entrain" => &bject(entrainruntime)(0) {}}