After upgrade - site locked down

[iftrueelsefalse]

Hi just installed the new beta, I know it comes with no warrenties, but now I get this error on my site:
Fatal error: Call to a member function getPath() on a non-object in ***\htdocs\libraries\joomla\application\categories.php on line 434

it comes from this function:

Code: Select all

	function setParent(&$parent)
	{
		if ($parent instanceof JCategoryNode || is_null($parent)) {
			if (!is_null($this->_parent)) {
				$key = array_search($this, $this->_parent->_children);
				unset($this->_parent->_children[$key]);
			}
			if (!is_null($parent)) {
				$parent->_children[] = & $this;
			}

			$this->_parent = & $parent;

			if ($this->id != 'root') {
				$this->_path = $parent->getPath(); // THIS LINE
				$this->_path[] = $this->id.':'.$this->alias;
			}

			if (count($parent->_children) > 1) {
				end($parent->_children);
				$this->_leftSibling = prev($parent->_children);
				$this->_leftSibling->_rightsibling = &$this;
			}
		}
	}

if I var_dump($parent) it is null. How can I find out what is calling this?

[iftrueelsefalse]

I fixed it by changing
if ($parent instanceof JCategoryNode || is_null($parent)) {
to
if ($parent instanceof JCategoryNode || !is_null($parent)) {

[nkwajoomla]

Thank you.