gistfile1.rb

class CustomDevise::SessionsController < Devise::SessionsController
  def create
    anonymous_cart = Cart.where(:security_hash => session[:security_hash]).last unless session[:security_hash].nil?
    resource = warden.authenticate!(:scope => resource_name, :recall => "#{controller_path}#new")
    set_flash_message :notice, :signed_in
    if anonymous_cart && !anonymous_cart.user_id?
      resource.cart.delete if resource.cart
      anonymous_cart.update_attribute(:user_id, resource.id)
    end
    sign_in_and_redirect(resource_name, resource)
  end
end