Reading static variables in child-classes failing?

[Simon Schick <simonsimcity@xxxxxxxxx>]

Hi, all

I'm currently testing something in PHP with static variables ...

Do you know, why I can't read static variables of a child class, even so
the variable is protected or public?

Here's an example:

class A {
  protected static $foo = "bar";
}

class B {
  public function readFoo() {
    return self::$foo;
  }
}

When now calling B::readFoo, I get the following error:

var_dump((new B())->readFoo());

PHP Fatal error:  Access to undeclared static property: B::$foo in php
shell code on line 1
PHP Stack trace:
PHP   1. {main}() php shell code:0
PHP   2. B->readFoo() php shell code:1

Fatal error: Access to undeclared static property: B::$foo in php shell
code on line 1

Call Stack:
   86.2643     231224   1. {main}() php shell code:0
   86.2666     231352   2. B->readFoo() php shell code:1

Tested using PHP 5.5.6

Bye,
Simon