Description:
------------
The magic __callStatic method throws a segmentation fault when the method name is an empty string.

Reproduce code:
---------------
class a {
        static function __callStatic($name, $arguments)
        {
                var_dump(array($name, $arguments));
        }
}
$a = 'a';
$b = '';
$a::$b($a);


Expected result:
----------------
array(2) {
  [0]=>
  string(0) ""
  [1]=>
  array(1) {
    [0]=>
    string(1) "a"
  }
}

- OR -


Fatal error: Function name must be a not empty string in __FILE__ on line 10


Actual result:
--------------
Internal server error when running on apache.
Segmentation fault running as CLI.