build_response

# File actionpack/lib/action_dispatch/routing/redirection.rb, line 35
      def build_response(req)
        uri = URI.parse(path(req.path_parameters, req))

        unless uri.host
          if relative_path?(uri.path)
            uri.path = "#{req.script_name}/#{uri.path}"
          elsif uri.path.empty?
            uri.path = req.script_name.empty? ? "/" : req.script_name
          end
        end

        uri.scheme ||= req.scheme
        uri.host   ||= req.host
        uri.port   ||= req.port unless req.standard_port?

        req.commit_flash

        body = ""

        headers = {
          "Location" => uri.to_s,
          "Content-Type" => "text/html; charset=#{ActionDispatch::Response.default_charset}",
          "Content-Length" => body.length.to_s
        }

        ActionDispatch::Response.new(status, headers, body)
      end