def sanitize_loginurl (self):
        """Make login configuration consistent."""
        url = self["loginurl"]
        disable = False
        if not self["loginpasswordfield"]:
            log.warn(LOG_CHECK,
            _("no CGI password fieldname given for login URL."))
            disable = True
        if not self["loginuserfield"]:
            log.warn(LOG_CHECK,
            _("no CGI user fieldname given for login URL."))
            disable = True
        if self.get_user_password(url) == (None, None):
            log.warn(LOG_CHECK,
            _("no user/password authentication data found for login URL."))
            disable = True
        if not url.lower().startswith(("http:", "https:")):
            log.warn(LOG_CHECK, _("login URL is not a HTTP URL."))
            disable = True
        urlparts = urlparse.urlsplit(url)
        if not urlparts[0] or not urlparts[1] or not urlparts[2]:
            log.warn(LOG_CHECK, _("login URL is incomplete."))
            disable = True
        if disable:
            log.warn(LOG_CHECK,
              _("disabling login URL %(url)s.") % {"url": url})
            self["loginurl"] = None
Make login configuration consistent.