class ActionView::Partials::PartialRenderer

def partial_path(object = @object)
  @partial_names[object.class.name] ||= begin
    object = object.to_model if object.respond_to?(:to_model)
    object.class.model_name.partial_path.dup.tap do |partial|
      path = @view.controller_path
      partial.insert(0, "#{File.dirname(path)}/") if partial.include?(?/) && path.include?(?/)
    end
  end
end