DocumentController::checkUpdatePermissions

protected function checkUpdatePermissions()
{
	$securityContext = $this->file->getStorage()->getCurrentUserSecurityContext();
	if(!$this->file->canUpdate($securityContext))
	{
		$this->errorCollection->add(array(new Error(Loc::getMessage('DISK_DOC_CONTROLLER_ERROR_BAD_RIGHTS'), self::ERROR_BAD_RIGHTS)));
		$this->sendJsonErrorResponse();
	}
}