Profile images throughout Confluence are broken when anonymous view profile permission is off

Steps to reproduce:

1. Upload a profile image
2. Make a change in a public space
3. Modify global permissions so that anonymous doesn't have access to user profiles
4. Log out
5. Go to the dashboard

A broken image will be present next to your user name in the recently updated section.

In firefox this is issue is not visible (broken image just doesn't render), but in Safari and possibly IE there is a broken image placeholder rendered instead of the image.

The same issue affects comments on wiki pages which will most likely affect more users than the dashboard alone.

An unfortunate side effect of this bug a significant performance penalty that is a result of http redirection to the login page and retrieval of this page for all links to profile images. Under normal circumstances all profile images are cached in the browser, so this is not an issue. Browsers however won't cache 302 redirections.