Description:
------------
https://github.com/php/php-src/blob/PHP-5.4.42/ext/spl/spl_array.c#L332
https://github.com/php/php-src/blob/PHP-5.4.42/ext/spl/spl_array.c#L360

Above links are pointed to bug. Looks like there is no fallback handler for BP_VAR_RW state and not triggering __get magic method. 

Test script:
---------------
https://gist.github.com/tugrul/14a621181a2e96ac9d81

Expected result:
----------------
PHP Notice:  Undefined index: foo in /srv/www/phptest/arrayobject.php on line 26
PHP Stack trace:
PHP   1. {main}() /srv/www/phptest/arrayobject.php:0
PHP Warning:  Creating default object from empty value in /srv/www/phptest/arrayobject.php on line 26
PHP Stack trace:
PHP   1. {main}() /srv/www/phptest/arrayobject.php:0


Actual result:
--------------
class OtherArrayObject#2 (1) {
  private $storage =>
  array(1) {
    'foo' =>
    class OtherArrayObject#3 (1) {
      private $storage =>
      array(1) {
        ...
      }
    }
  }
}