Description:
------------
I found this while using propel. It uses DateTime class for storing.
After retrieving the class from a Session the member is broken.

The code creates a session variabel "v" with the given class if not found.On the second call to the script the class is retrievies from session. The member x is broken.


Reproduce code:
---------------
<?php
  class c {
    protected $v;

    function print_type() {
      if ( $this->v instanceof DateTime ) {
        print "x is DateTime\n";
      }
    }
    function get_v() {
      return $this->v;
    }
    function set_v($i) {
      $this->v=$i;
    }
  }

session_start();

if ( !isset($_SESSION["x"] )) {
  $x = new c();
  $x->set_v( new DateTime());
  $_SESSION["x"]=$x;
  print "New object created\n";
}

$_SESSION["x"]->print_type();
print $_SESSION["x"]->get_v()->format("d.m.Y");
?>


Expected result:
----------------
First call:
New object created x is DateTime 08.08.2007

Second call:
x is DateTime 08.08.2007

Actual result:
--------------
First call:
New object created x is DateTime 08.08.2007

Second call:
x is DateTime Warning: DateTime::format(): The DateTime object has not been correctly initialized by its constructor in /home/peter/workspace/Kurse/html/t1.php on line 28