Compressing packages with bzip2 instead gzip?

[Phillip Susi]

Aigars Mahinovs wrote:
> My bad - I confused zsync and debdiff approaches.
> 
> However, making zsync avare of the internals of the .deb file more
> would be quite hard - imagine that one small part of a large file has
> changed in the .deb. The client must no only detect which file and
> which part of the file has changed (quite trivial and already part of
> the zsync), but also calculate which parts of the .deb (also know as
> .tar.gz.ar) to fetch so that the file in question or the particular
> part of the particular file in question can be decompressed. That
> would be a quite significant mathematical problem.
> 

The required change is rather straightforward; you just extract and 
decompress the members of the .deb, zsync, then recompress and rebuild 
the deb.  What's so hard about that?