Subject: Re: [PATCH] git-mergetool: add support for ediff

From: Theodore Tso <[email-masked]>
Date: Sun, 1 Jul 2007 23:05:21 -0400

On Sun, Jul 01, 2007 at 07:32:59PM -0700, Junio C Hamano wrote:
> Theodore Tso <[email-masked]> writes:
> 
> > Unfortunately, it's not enough.  Ediff doesn't have an "abort" command
> > which returns a non-zero exit status, and when you use the "quit"
> > command, it asks you a series of obnoxious questions:
> >
> > ...
> > Alternatively, we could patch around the problem.  The following emacs
> > lisp code fixes the ediff issues:
> 
> But that would be changing the behaviour globally, and not
> limited to the particular session invoked from git-mergetool,
> wouldn't it?  If that is the case it would be a hard sell to
> Emacs users, especially the ones that keep their Emacs running
> forever and have emacsclient as their EDITOR, I would think.

The emacs lisp code I gave there was the minimal necessary so it
could be passed on the command-line; I was trying to keep it small.

Obviously, the patch that would have to get sent to the ediff folks
would have to be much more generalized --- in fact, probably the right
thing to do is to send a full patch that actually implemented
ediff-merge-files-command and ediff-merge-files-with-ancestoers-commands.

As far as people using emacsclient as their editor, it would be simple
enough to have the emacs lisp code test to see if
server-buffer-clients is non-nill; if it is, then we know that this
merge request was trigered by emacsclient, and so (server-done) should
be called instead of (kill-emacs).  Emerge does not do this; arguably
this is a bug in emerge.

The other way we could deal with this problem is to fire up a separate
emacs even if EDITOR is emacsclient, on the theory that
EDITOR=emacsclient meants that the user prefers emacs, but it doesn't
necessarily mean that we have to *use* emacsclient, especially when
emerge currently doesn't DTRT with emacsclient.

One thing that did cross my mind is that we could put code which
patched ediff.el and emerge.el in /usr/share/git/lisp/... and then
passed called emacs with something like this "emacs -l
$sharedir/lisp/ediff-patches.el ...".  But this implies packaging
emacs lisp files with git, and I'm not at ALL sure we want to go
there.  Personally, I still like kdiff3 as my personal favorite
mergetool, and given that emacs starts up pretty fast these days, I've
given up on emacsclient, but I know there are certainly people who use
them.

(Mmmm...., I just pulled down an early emacs 23 snapshot with Xft
support enabled, so I can enjoy the anti-aliased font goodness.  Even
with all of the Gtk and Xft bloat, the emacs 23 snapshot is still
quick snappy to fire up.)

					- Ted