protected function _assertValidExtend($extendingSection, $extendedSection)
{
// detect circular section inheritance
$extendedSectionCurrent = $extendedSection;
while (array_key_exists($extendedSectionCurrent, $this->_extends)) {
if ($this->_extends[$extendedSectionCurrent] == $extendingSection) {
/** @see Zend_Config_Exception */
require_once 'Zend/Config/Exception.php';
throw new Zend_Config_Exception('Illegal circular inheritance detected');
}
$extendedSectionCurrent = $this->_extends[$extendedSectionCurrent];
}
// remember that this section extends another section
$this->_extends[$extendingSection] = $extendedSection;
}