Description:
------------
Only happens in the CVS-version:
After the code below has been executed twice (waiting at least two seconds between first and second run) Apache freezes on the apc_fetch-line until max_execution_time has been reached.

PHP 5.1.6, 5.2.0 5.2.1 RC1
Apache 1.3.37
Fresh CVS checkout (works, however, fine with APC 3.12)

Reproduce code:
---------------
if (!apc_fetch('g')) {
  $a = new a();
  apc_store('g', $a->d(), 2);
}
echo 'hello';
class a {
	var $e;
	function a() {
		$this->e[0] = new b();
		$this->e[1] = new b();
	}
	function d() {
		return array(0 => $this->e[0]->d(), 1 => $this->e[1]->d());
	}
}
class b {
	var $e;
	function b () {
		$this->e[] = $a;  //$a doesn't exist
	}
	function d() {
		$f = &$this->e;
		return $f;
	}
}

Expected result:
----------------
"hello" written on the screen

Actual result:
--------------
PHP Fatal error:  Maximum execution time of 30 seconds exceeded