Description:
------------
If any session key contains character '|', the whole session will not be saved (and will be erased!)



Reproduce code:
---------------
<?php

session_start();

$_SESSION['La'] = 'Trine';
$_SESSION['a|b'] = 'the killer';

session_write_close();

// test

session_start();
var_dump($_SESSION);


?>

Expected result:
----------------
array(2) {
  ["La"]=>
  string(5) "Trine"
  ["a|b"]=>
  string(10) "the killer"
}


Actual result:
--------------
PHP 4.3.9-4.4.2 & 5.0.2-5.1.2

array(0) {
}

PHP 5.0.0-5.0.1 and previous PHP4

array(3) {
  ["La"]=>
  string(5) "Trine"
  ["a"]=>
  NULL
  ["b"]=>
  string(10) "the killer"
}