Re: The Gnus repository is switching to Git as of 2010-04-19

[Ted Zlatanov <tzz@lifelogs.com>]

On Mon, 19 Apr 2010 14:50:03 -0400 Stefan Monnier <monnier@iro.umontreal.ca> wrote: 

SM> Here is the way I imagine it might work:
SM> - take an Emacs Bzr branch.
SM> - massage it with "bzr mv", "bzr rm", and "bzr add" to make it look
SM>   exactly like the corresponding revision in Gnus's Git.
SM> - call it "Gnus Bzr branch".
SM> - then use magic to make this Gnus Bzr branch sync bidirectionally with
SM>   the corresponding Git branch.

SM> We should then be able to use manually "bzr merge" from the Emacs Bzr
SM> branch to the Gnus Bzr branch and vice versa without too much pain (tho
SM> it will suffer from many spurious conflicts on files that are in one
SM> branch but not in the other, so some extra scripting will be helpful to
SM> ease the pain).

SM> If someone knows a magician that can take care of the Bzr<->Git part,
SM> I'm all ears.

I asked Carsten (org-mode) for guidance as he does something similar.

git-bzr supports push and pull (bzr-git only supports pull) so maybe it
makes sense to put the magic on the Git side.  In that case it may also
make sense to set up the "for-emacs" synchronization branch inside Gnus
and simply pull all the commits out of Bazaar for a specific set of
files.  IOW, instead of massaging the file locations in the for-emacs
branch, I could assemble a map of "gnus-file-name <-> emacs-file-name"
for all the files that need to be synchronized and then only look at
commits that involve those files.  So the "magic" would not only
synchronize but also translate and make rearranging the files
unnecessary.

I don't know which approach is best, honestly, so Carsten's opinion will
be valuable in addition to yours and anyone else willing to help.
Katsumi Yamaoka and Miles Bader, especially, may have interesting views
as they've worked on this synchronization with the CVS side.

Ted