Description:
------------
$this refers to the caller in static calls of non-static methods.

If the function is correctly set as static, then $this is ok.

That may be a problem as I'm provinding a library that has to be PHP4/PHP5 compliant. 

(in PHP4, "$this" would have not been set)

Reproduce code:
---------------
$obj = new Caller ();
$obj->showResult ();

class Caller {
 function showResult (){
  echo StaticClass::staticCallAsOfPHP4 ();
 }
}

class StaticClass {
 static function staticCallAsOfPHP4 (){
  return (isset ($this)) ? get_class ($this) : 'none';
 }
}

Expected result:
----------------
"none "
(because of the static call, as of PHP4)

Actual result:
--------------
"Caller"