redirect users back on registration failure

app/controllers/registrations_controller.rb

@@ -21,7 +21,7 @@ class RegistrationsController < Devise::RegistrationsController
 
       flash[:error] = @user.errors.full_messages.join(" - ")
       Rails.logger.info("event=registration status=failure errors='#{@user.errors.full_messages.join(', ')}'")
-      render :new
+      redirect_to :back
     end
   end
 

spec/controllers/registrations_controller_spec.rb

@@ -112,9 +112,9 @@ describe RegistrationsController do
         flash[:error].should_not be_blank
       end
 
-      it "re-renders the form" do
+      it "redirects back" do
         get :create, @invalid_params
-        response.should render_template("registrations/new")
+        response.should be_redirect
       end
     end
   end