<?php
Class Frog {
  protected static $colour = 'green';
  static function show() { var_dump(Frog::$colour); }
}
Class SpecialFrog extends Frog {
  public static $colour;
  static function show() { var_dump(SpecialFrog::$colour); }
}
SpecialFrog::$colour = 'blue';

Frog::show();
SpecialFrog::show();
?>

---- Output before patch (imho buggy) ----
string(4) "blue"
string(4) "blue"

---- Output after patch ----
string(5) "green"
string(4) "blue"