class ActionView::Helpers::FormBuilder

def collection_select(attribute, collection, value_method, text_method, options={}, html_options={})
  if value_method.respond_to?(:call) || text_method.respond_to?(:call)
    collection = collection.map do |item|
      value = value_for_collection(item, value_method)
      text  = value_for_collection(item, text_method)
      default_html_options = default_html_options_for_collection(item, value, options, html_options)
      disabled = value if default_html_options[:disabled]
      selected = value if default_html_options[:selected]
      [value, text, selected, disabled]
    end
    [:disabled, :selected].each do |option|
      option_value    = collection.map(&:pop).compact
      options[option] = option_value if option_value.present?
    end
    value_method, text_method = :first, :last
  end
  original_collection_select(attribute, collection, value_method, text_method, options, html_options)
end