Steps to reproduce (Not on a Wikimedia wiki)

1. You need $wgUploadPath to be a relative url (This is the default, however not what is set on Wikimedia)
2. Put a (local) image on some page
3. View that page with url parameter ?action=render . Expected behaviour, no relative urls (like links). Actual behaviour, the src attribute on <img> tags are still relative

This would cause breakage if using Foreign repos (including ForeignDBRepo) and the foreign image description page had an image from the foreign repo on it (Since the relative url is just copied, but no longer points to the right server).

Reported on irc by cboltz

Version: unspecified
Severity: normal