fix permission check

    public_only = _user_has_permission(user, project_id, PERM_COLLECTION_PUBLIC_ONLY)

    if public_only:

        only_published = True

        if not parent.public_access:

        if not parent.public_access and parent_id:

            raise ServiceException(CAN_ONLY_SHOW_PUBLIC_COLLECTIONS_CONTENT)

    limit_from = int(limit_from)

    limit_to = int(limit_to)