public function prepareForRestart() {
		parent::prepareForRestart();
		// if the file we've been building is missing, lets fix it up
		if (!$this->tempFile || !file_exists($this->tempFile)) {
			$tmpfile = tempnam(getTempFolder(), 'postsitemap');
			if (file_exists($tmpfile)) {
				$this->tempFile = $tmpfile;
			}
			$this->currentStep = 0;
			$this->toProcess = $this->getProcessIds();
		}
	}