ActiveView::Helpers::InstanceTag

Hi lads!
I have a question about ActiveView::Helpers::InstanceTag

This class has method
    private
        def add_default_name_and_id(options)
          if options.has_key?("index")
            options["name"] ||= tag_name_with_index(options["index"])
            options["id"] ||= tag_id_with_index(options["index"])
            options.delete("index")
          elsif defined?(@auto_index)
            options["name"] ||= tag_name_with_index(@auto_index)
            options["id"] ||= tag_id_with_index(@auto_index)
          else
            options["name"] ||= tag_name + (options.has_key?
('multiple') ? '[]' : '')
            options["id"] ||= tag_id
          end
        end

May be i don't know some thing, but how i can told InstanceTag to
build tag name with 'index' which i pass and 'multiple' at once!?

I think that author intend this code:
  private
      def add_default_name_and_id(options)
         if options.has_key?("index")
           options["name"] ||= tag_name_with_index(options["index"])
           options["id"] ||= tag_id_with_index(options["index"])
           options.delete("index")
         elsif defined?(@auto_index)
           options["name"] ||= tag_name_with_index(@auto_index)
           options["id"] ||= tag_id_with_index(@auto_index)
         else
           options["id"] ||= tag_id
           options["name"] ||= tag_name
         end

         options["name"] += '[]' if options.has_key?('multiple')
      end