Description:
------------
If you call uasort with one callback function and then call array_udiff with another callback function, this last call will use first's callback. If we first call array_udiff and then call uasort, everything goes well.


Reproduce code:
---------------
<?
class p
{
   public $x;
   function __construct($x){$this->x=$x;}
}
function a(&$a, &$b){return $a->x - $b->x;}
function b(&$a, &$b){return $a->y - $b->y;}

$p1 = array(new p(2), new p(1), new p(0));
$p2 = array(new p(0), new p(2), new p(3));

uasort($p1, 'a');
print_r($p1);
echo "\n";
print_r(array_udiff($p1,$p2, 'b')); 
?>

Expected result:
----------------
Notice: Undefined property: p::$y in tst.php on line 8

Actual result:
--------------
Array
(
    [2] => p Object
        (
            [x] => 0
        )

    [1] => p Object
        (
            [x] => 1
        )

    [0] => p Object
        (
            [x] => 2
        )

)
Array
(
    [1] => p Object
        (
            [x] => 1
        )

)