I've got data objects defined with private properties and respective getters/setters

class DataObject
{
private $ID;

public function getID() { return $this->ID; }
public function setID( $value ) { $this->ID = $value; }
}

Twig_Template->getAttribute() method uses property_exists() function to check whether required attribute is object property. But since PHP 5.3 property_exists() checks the existence of a property independent of accessibility. So script hangs on private property access instead of using public getter method.