Description:
------------
Derived classes get wrong context inside the thread. Please see example below.

Test script:
---------------
abstract class Animal
{
	protected abstract function getName();
	
	public function printName()
	{
		echo __CLASS__ . " -> " . $this->getName() . "\n";
	}
}

class Bird extends Animal
{
	protected function getName()
	{
		return "Bird";
	}
}

$bird = new Bird();
$bird->printName();

class MyThread extends Thread
{
	private $animal;
	
	public function __construct( $animal )
	{
		$this->animal = $animal;
	}
	
	public function run()
	{
		$this->animal->printName();
	}
}

$thread = new MyThread( $bird );
$thread->start();
$thread->join();


Expected result:
----------------
The protected function of the derived class should be called like outside the thread.

Actual result:
--------------
Normal PHP:
Animal -> Bird

Inside Thread:
PHP Fatal error:  Call to protected method Bird::getName() from context 'Animal' in thread_test.php on line 7