def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def disable_plugin(plugin):
    try:
        plugin = get_plugin(plugin)
    except KeyError:
        flash(_("Plugin %(plugin)s not found.", plugin=plugin.name), "danger")
        return redirect(url_for("management.plugins"))

    try:
        plugin.disable()
        flash(_("Plugin %(plugin)s disabled. Please restart FlaskBB now.",
                plugin=plugin.name), "success")
    except OSError:
        flash(_("It seems that FlaskBB does not have enough filesystem "
                "permissions. Try creating the 'DISABLED' file by "
                "yourself instead."), "danger")

    return redirect(url_for("management.plugins"))