Description:
------------
Method 'append()' in class extended from ArrayObject crash PHP with Windows message (sorry, it's in French) :

php-cgi.exe - Erreur d'application
L'instruction ? "0x10003cfb0" emploie l'adresse m?moire "0x00000008". La m?moire ne peut pas ?tre "read".

This bug only appears when method 'offsetSet()' is redefined.
Web server IIS 5.1 under Windows XP Service Pack 2.

Reproduce code:
---------------
class Collection extends ArrayObject
{
   public function add($dataArray)
   {
      foreach($dataArray as $value) $this->append($value);
   }

   public function offsetSet($index, $value)
   {
      parent::offsetSet($index, $value);
   }
}

$data1=array('one', 'two', 'three');
$data2=array('four', 'five');

$foo=new Collection($data1);
$foo->add($data2);

print_r($foo->getArrayCopy());

Expected result:
----------------
Array
(
    [0] => one
    [1] => two
    [2] => three
    [3] => four
    [4] => five
)

Actual result:
--------------
CGI Error
The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are:

(no headers are printed)