Description:
------------
When we call the method foo() of some class A in a static context inside the object B, the method can see $this as an object B. However, when method doesn't exist and __callStatic is triggered, $this is undefined. Why is that so?

Test script:
---------------
abstract class A {
	function foo() { # non-static on purpose
		var_dump($this);
	}
	static function __callStatic($method, $args) {
		var_dump($this);
	}
}

class B {
	function test() {
		A::foo();
		A::someMethod();
	}
}

$o = new B();
$o->test();

Expected result:
----------------
object(B)[4]
object(B)[4]

Actual result:
--------------
object(B)[4]
null