normalize_argument_to_redirection

# File actionpack/lib/action_controller/assertions/response_assertions.rb, line 136
        def normalize_argument_to_redirection(fragment)
          after_routing = @controller.url_for(fragment)
          if after_routing =~ %r{^\w+://.*}
            after_routing
          else
            # FIXME - this should probably get removed.
            if after_routing.first != '/'
              after_routing = '/' + after_routing
            end
            @request.protocol + @request.host_with_port + after_routing
          end
        end