Description:
------------
Hi All,

Problem:

When loading classes with __autoload, restoring objects from session works regardless whether session_start() was called before or after __autoload was declared.

When loading classes with spl_autoload_register, restoring objects from session only works when session_start() called after registering loader, and returns __PHP_Incomplete_Class object when called before registering loader.

PHP and OS versions:
- 5.5.1 on Windows 2008 Server 64 bit
- 5.5.9 on Ubuntu Linux 14.04 64 bit

Preparation:
Create file Foo.php with empty declaration of class Foo.


Test script:
---------------
<?php
session_start();
spl_autoload_register(function ($className) { include "{$className}.php"; });
isset($_SESSION["foo"]) or $_SESSION["foo"] = new Foo();
var_dump($_SESSION);


Expected result:
----------------
array(1) { ["foo"]=> object(Foo)#2 (0) { } } 

Actual result:
--------------
array(1) { ["foo"]=> object(__PHP_Incomplete_Class)#1 (1) { ["__PHP_Incomplete_Class_Name"]=> string(3) "Foo" } }