request.rb

    def cookies
      return {}  unless @env["HTTP_COOKIE"]

      if @env["rack.request.cookie_string"] == @env["HTTP_COOKIE"]
        @env["rack.request.cookie_hash"]
      else
        @env["rack.request.cookie_string"] = @env["HTTP_COOKIE"]
        # According to RFC 2109:
        #   If multiple cookies satisfy the criteria above, they are ordered in
        #   the Cookie header such that those with more specific Path attributes
        #   precede those with less specific.  Ordering with respect to other
        #   attributes (e.g., Domain) is unspecified.
        @env["rack.request.cookie_hash"] =
          Utils.parse_query(@env["rack.request.cookie_string"], ';,').inject({}) {|h,(k,v)|
            h[k] = Array === v ? v.first : v
            h
          }
      end
    end