Description:
------------
When a method is inherited from a base class it seems that it retains its context. When it's called from derived class object, it turns out that method cannot access private fields of it's own (derived class) object.

What's strange, the inherited method can access protected fields easily. As if 'protected' opened access not only for derived classes but for base classes too.

This is a key issue if one wants to code the accessor only once, in base class so that any derived class could use it and provide read-only access to any field.

Reproduce code:
---------------
<?php 
class ParentClass {
	protected $a = 'ParentClass<br>';
	public function get($arg) {
		return $this->$arg;
	}
}

class ChildClass extends ParentClass{
	protected $b = 'ChildClass - Protected<br>';
	private $c = 'ChildClass - Private<br>';
	
}

$test = new ChildClass;
echo $test->get('a');
echo $test->get('c'); //fatal error
echo $test->get('b'); //strange - it's ok
?>

Expected result:
----------------
ParentClass
ChildClass - Protected
ChildClass - Private

Anyway, 'protected' field should be accessible only in derived classes and where declared.

Actual result:
--------------
ParentClass
ChildClass - Protected

Fatal error: Cannot access private property childclass::$c