Strange behaviour

cookie.rb

      def load_session(env)
        data = unpacked_cookie_data(env)
        data = persistent_session_id!(data)
        [data["session_id"], data]
      end

      def unpacked_cookie_data(env)
        env["rack.session.unpacked_cookie_data"] ||= begin
          request = Rack::Request.new(env)
          session_data = request.cookies[@key]

          if @secrets.size > 0 && session_data
            session_data, digest = session_data.split("--")

            if session_data && digest
              ok = @secrets.any? do |secret|
                secret && digest == generate_hmac(session_data, secret)
              end
            end

            session_data = nil unless ok
          end

          coder.decode(session_data) || {}
        end
      end

      def persistent_session_id!(data, sid=nil)
        data ||= {}
        data["session_id"] ||= sid || generate_sid
        data
      end