title: Does switching to a custom domain in Google App Engine cause the AppSpot domain to stop working?
body: <p>I have released Apps that access my Google App Engine instance via <code>my_app.appspot.com</code>.
  I want to change to using a custom domain and then submit updates to my apps so they start using the new domain. However there will be an overlap period where my Apps out in the wild that don't get updated and will still be trying to access <code>my_app.appspot.com</code></p>
  
  <p>What I really want is to have GAE simultaneously use my custom domain and the appspot domain, but I can't find any information on whether this will work or not. Can anyone confirm if appspot keeps working after setting up a custom domain (with SSL)?</p>