Request format.all

Requesting /attachments/1.all does not work in Rails 3. It was changed here:

https://github.com/rails/rails/commit/7e280c3bff8ac25f1c1938aeaeb1d0b4c0fbb726

The use case is a show action such as:

def show
  @attachment = Attachment.find(params[:id])

  respond_to do |format|
    format.html
    format.any { download }
  end
end

The pros of using this approach is take advantage of Cancan and
InheritedResources defaults. What do you thing about it?