PHP Bug in recursive unserialization

.gitignore

*.out
a.ser

A.php

<?

class A {
}

B.php

<?

class B {
}

run_test.sh

#!/bin/sh
php serialize_autoload.php > before.out
php unserialize_autoload.php > after.out
echo "Original =========="
cat before.out
echo 
echo "Unserialized ======"
cat after.out
echo 
echo "Diff =============="
(diff -a before.out after.out && echo "Passed, no differences") ||
echo "FAILED ============"

serialize_autoload.php

<?php
require "setup.php";

$a = new A();
$b = new B();
$c = new B();
$a->b = $b;
$a->b1 = $b;
$a->c = $c;
$a->c1 = $c;
var_dump($a);
file_put_contents('a.ser', serialize($a));

setup.php

<?php
function __autoload($name)
{
   echo "in autoload: $name\n";
   //  This call causes the bug
   unserialize('i:4;');
   require "$name.php";
   return true;
}

unserialize_autoload.php

<?php
require 'setup.php';

var_dump(unserialize(file_get_contents("a.ser")));

Reported a bug in PHP here: https://bugs.php.net/bug.php?id=62836

And it got fixed here: php/php-src@0b23da1

This bug is fixed as of php 5.4.7