Description:
------------
when passing an object by value to a function it alters the original object and not a copy of it. Here is a script to reproduce it. I included the handling for passing strings which works as expected unlike passing objects.
  

Reproduce code:
---------------
<?php
class User
{
  var $name;
  function User(){$this->name = "tony";}
}
function changeUserByRef(&$user) { $user->name = "changeUserByRef";}
function changeUserByValue($user) { $user->name = "changeUserByValue";}


function changeStringByRef(&$str) { $str = "changeStringByRef";}
function changeStringByValue($str) { $str = "changeStringByValue";}

$user = new User();
echo($user->name .  '</br>'  );
changeUserByRef($user);
echo("changeUserByRef = " . $user->name .  '</br>'  );

$user->name = "tony";
echo($user->name .  '</br>'  );
changeUserByValue($user);
echo("changeUserByValue = ".  $user->name .  '</br>'  );

echo('<hr />');

$user->name = "tony";
echo($user->name .  '</br>'  );
changeStringByRef($user->name);
echo("changeStringByRef = " . $user->name .  '</br>'  );


$user->name = "tony";
echo($user->name .  '</br>'  );
changeStringByValue($user->name);
echo("changeStringByValue = " . $user->name .  '</br>'  );

?>

Expected result:
----------------
tony
changeUserByRef = changeUserByRef
tony
changeUserByValue = tony
---------------------------------------------------
tony
changeStringByRef = changeStringByRef
tony
changeStringByValue = tony

Actual result:
--------------
tony
changeUserByRef = changeUserByRef
tony
changeUserByValue = changeUserByValue
---------------------------------------------------
tony
changeStringByRef = changeStringByRef
tony
changeStringByValue = tony