just to update this bug,

RFC 6249 ( http://tools.ietf.org/html/rfc6249 ) describes this, Metalink/HTTP.

poeml, what should a student know about this bug? where to start within the source?

what configurable options do you need?
On (default) /Off
Amount of Mirrors to emit over HTTP?
which full file hashes to include? all known full file hashes, or just some?