Devise after_sign_in_path error: Filter chain halted as :require_no_authentication

[Leonardo Costa]

I'm following the Devise wiki to redirect the user to the current page after signing in (https://github.com/plataformatec/devise/wiki/How-To:-Redirect-back-to-current-page-after-sign-in,-sign-out,-sign-up,-update)

However I'm getting the following error:

Started GET "/login" for 127.0.0.1 at 2014-05-12 18:52:52 -0300
Processing by Devise::SessionsController#new as HTML
  ←[1m←[35mUser Load (3.0ms)←[0m  SELECT "users".* FROM "users" WHERE "users"."id" = 3 ORDER BY "users"."id" ASC LIMIT 1
Redirected to http://localhost:3000/login
Filter chain halted as :require_no_authentication rendered or redirected
Completed 302 Found in 8ms (ActiveRecord: 3.0ms)

This is the code I have on my Application Controller:

  after_filter :store_location

  def store_location
    # store last url - this is needed for post-login redirect to whatever the user last visited.
    if (request.fullpath != "/users/sign_in" &&
        request.fullpath != "/users/sign_up" &&
        request.fullpath != "/users/password" &&
        !request.fullpath.match("/users") &&
        !request.xhr? && # don't store ajax calls
        request.format == "text/html" || request.content_type == "text/html")
      session[:previous_url] = request.fullpath 
      session[:last_request_time] = Time.now.utc.to_i
    end
  end

  def after_sign_in_path_for(resource)
    session[:previous_url] || root_path
  end

routes.rb

Myapp::Application.routes.draw do
  ActiveAdmin.routes(self)
  devise_for :users, :controllers => { :omniauth_callbacks => "users/omniauth_callbacks", :registrations => "registrations" }, :skip => [:sessions] 
  as :user do
    get 'login' => 'devise/sessions#new', :as => :new_user_session
    post 'login' => 'devise/sessions#create', :as => :user_session
    delete 'logout' => 'devise/sessions#destroy', :as => :destroy_user_session
  end

  root  'static_pages#home'

Any idea why this is happening? Thanks