Bidi support

[Stephen J. Turnbull]

Stefan Monnier writes:

 > Agreed.  The more I think about it, the more I think we need to open
 > a new branch for "what will become emacs-24".

That's what I thought, too, about XEmacs 21.5.  I was wrong.  We ended
up having to uproot the trunk and move it to a branch, and graft the
21.5 branch back as the trunk.  Long-term development belongs either
on the trunk, or in feature branches.  Not on a long-term development
branch which collects several features.

Once you move to bzr, this will become less costly, but remember that
in bzr (like CVS, but not so disastrously as CVS) some branches are
more equal than others in the way they are presented to the user.
It's not like git where you just do

git branch emacs-23 master
git branch -f master emacs-24
git branch -D emacs-24            # optional

and everything's alright.

 > I think it will stay unstable for too long, so it's not good enough for
 > the current trunk (which I'd like to keep for shorter-term changes).

I know how you feel, but doing things this way is either going to be a
lot of work (synching "short-term changes" from the trunk to the
long-term branch -- in my experience, people work on features like
unicode and bidi in spurts, and they're pervasive changes so conflicts
are frequent if you come back every month or so), or discourage work
on the long-term branch (conflict resolution is enthusiasm-draining).

It also fails to encourage work on the instabilities by third parties.

I may be all wet; ask Ken'ichi and Miles how they feel about the long
stalls on the unicode and lexbind branches.  And maybe bzr will be
flexible enough to handle it, but you won't know that until Christmas,
I would guess.  I'm still finding new things I dislike about Mercurial
20 months after our conversion....