_url_host_allowed?

# File actionpack/lib/action_controller/metal/redirecting.rb, line 304
      def _url_host_allowed?(url)
        url_to_s = url.to_s
        host = URI(url_to_s).host

        if host.nil?
          url_to_s.start_with?("/") && !url_to_s.start_with?("//")
        else
          host == request.host || self.class.allowed_redirect_hosts_permissions&.allows?(host)
        end
      rescue ArgumentError, URI::Error
        false
      end