Merge pull request #189 from codefirst/id/189

ActionController::ActionControllerError: Cannot redirect to nil! refs #189

app/controllers/login_controller.rb

@@ -33,7 +33,7 @@ def logout
       session.delete :cached_current_user
       session.delete :current_user_id
     end
-    redirect_to request.referer
+    redirect_to(request.referer || root_path)
   end
 
   def failure

spec/controllers/login_controller_spec.rb

@@ -11,14 +11,25 @@
 
   }
   context "ログアウト後" do
-    before do
-      @user = User.new.tap{|user| user.save! }
-      session[:current_user_id] = @user.id
-      request.stub(:referer) { 'http://localhost' }
-      post :logout
+    context "referer is nil" do
+      before do
+        @user = User.new.tap{|user| user.save! }
+        session[:current_user_id] = @user.id
+        post :logout
+      end
+      subject { response }
+      it { should redirect_to root_path }
+    end
+    context "referer is not nil" do
+      before do
+        @user = User.new.tap{|user| user.save! }
+        session[:current_user_id] = @user.id
+        request.stub(:referer) { 'http://localhost' }
+        post :logout
+      end
+      subject { session }
+      its([:current_user_id]) { should be_nil }
     end
-    subject { session }
-    its([:current_user_id]) { should be_nil }
   end
 
   context "callback" do