Description:
------------
When zend.ze1_compatibility_mode is On, object copying is not compliant to PHP4. Namely, objects are not deep-copied on assignment. This may cause substantial problems to legacy applications that rely on the compatibility mode.

Reproduce code:
---------------
$a->y->z = 0;
$b = $a;      // should perform deep copy of $a
$b->y->z = 1; // hence this should have no effect on $a
var_dump($a);


Expected result:
----------------
object(stdClass)#1 (1) {
  ["y"]=>
  object(stdClass)#2 (1) {
    ["z"]=>
    int(0) // <--
  }
}


Actual result:
--------------
object(stdClass)#1 (1) {
  ["y"]=>
  object(stdClass)#2 (1) {
    ["z"]=>
    int(1) // because $a->y and $b->y are still one object after the assignment
  }
}