Double-decorating objects

house_controller.rb

class HouseController < ActionController::Base
  def show
    @house = HouseDecorator.decorate(House.find(params[:id]))
    @windows = WindowBlindsDecorator.decorate(@house.windows)
    # @windows would be inadvertently double-decorated
    # (though this is prevented by previous fix from 
    # https://github.com/jcasimir/draper/commit/c945cce6f3147c805b4db73580c198016750ad60)
    # My pull request would cause an error to be thrown instead.
  end

  def edit
    @house = HouseDecorator.decorate(House.find(params[:id]))
    @windows_with_blinds = WindowBlindsDecorator.decorate(@house.windows)
    # As above, double-decoration is prevented

    @windows_with_blinds_and_drapes = WindowDraperDecorator.decorate(@windows_with_blinds)
    # This is now incorrect. We now have a window with drapes, and no blinds,
    # due to the previous fix discarding any previous decorator.
    # This would work correctly with my pull request.
  end
end

house_decorator.rb

class HouseDecorator < Draper::Base
  def windows
    WindowBlindsDecorator.decorate(model.windows)
  end
end