Tests that persistent parameters can be overridden with nulled-out values.

Source

						public function testOverridingPersistentParameters() {
		Router::connect(
			'/admin/{:controller}/{:action}',
			array('admin' => true),
			array('persist' => array('admin', 'controller'))
		);
		Router::connect('/{:controller}/{:action}');

		$request = Router::process(new Request(array('url' => '/admin/posts/add', 'base' => '')));
		$expected = array('controller' => 'posts', 'action' => 'add', 'admin' => true);
		$this->assertEqual($expected, $request->params);
		$this->assertEqual(array('admin', 'controller'), $request->persist);

		$url = Router::match(array('action' => 'archive'), $request);
		$this->assertEqual('/admin/posts/archive', $url);

		$url = Router::match(array('action' => 'archive', 'admin' => null), $request);
		$this->assertEqual('/posts/archive', $url);
	}