render_optional_error_file (ActionController::Rescue)

    # File lib/action_controller/rescue.rb, line 107
          def render_optional_error_file(status_code)
            status = interpret_status(status_code)
            locale_path = "#{Rails.public_path}/#{status[0,3]}.#{I18n.locale}.html" if I18n.locale
            path = "#{Rails.public_path}/#{status[0,3]}.html"

            if locale_path && File.exist?(locale_path)
              render :file => locale_path, :status => status, :content_type => Mime::HTML
            elsif File.exist?(path)
              render :file => path, :status => status, :content_type => Mime::HTML
            else
              head status
            end
          end