url_for.rb

module ActionController
  module UrlFor
    extend ActiveSupport::Concern

    include AbstractController::UrlFor

    def url_options
      @_url_options ||= super.reverse_merge(
        :host => request.host,
        :port => request.optional_port,
        :protocol => request.protocol,
        :_path_segments => request.symbolized_path_parameters
      ).freeze

      if _routes.equal?(env["action_dispatch.routes"])
        @_url_options.dup.tap do |options|
          options[:script_name] = request.script_name.dup
          options.freeze
        end
      else
        @_url_options
      end
    end

  end
end