FIX: Use exact patht to ensure we always redirect with the right format.

app/controllers/application_controller.rb

@@ -578,7 +578,7 @@ class ApplicationController < ActionController::Base
         else
           # save original URL in a cookie (javascript redirects after login in this case)
           cookies[:destination_url] = destination_url
-          redirect_to :login
+          redirect_to "/login"
         end
       end
     end