Re: Messing with the VC history

[Eli Zaretskii <eliz@gnu.org>]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Date: Sun, 16 Nov 2014 17:05:28 +0100
> 
> >> To welcome my first commit to Emacs, some people complicated the VC
> >> history with unnecessary noise burying the happy event into a
> >> merge-fest.
> >
> > I see nothing terribly messy there.  You will see very similar picture
> > when someone merges their local feature branch, and then pushes
> > upstream.
> 
> That's not the same at all. Feature branches and incorporating changes
> from other public development branches *shall* be merged. What I'm
> describing is an scenario where merges are created just because someone
> pushed changes since your last `pull'.

But that's Git's default behavior: "merge" commits.  So when Stefan
merged from the branch, Git made a merge-commit, producing the same
effect as if Stefan were to merge his local feature branch.  What can
we do if the tool behaves like that?

> Apart from the noise on the VC history, this procedure has a
> recursive nature: A tries to push but he can't because there are new
> commits on the remote branch; then he pulls (+merges) and
> pushes. Meanwhile, B was hacking and now tries to push, but he can't
> because the changes pushed by A, so he pulls (+merges).  Then C (or
> A again) tries to push...

Yes, but (a) this danger existed with bzr as well, and (b) the race
you describe is in practice very rare, so the problem normally doesn't
happen, and having it here and there is not different from local
merges.

> > Maybe you don't like merge-commits in general, but then it's a
> > different discussion altogether.
> 
> I don't like merge commits that add nothing but noise and confussion to
> the VC history.

I didn't become confused when I looked at that part of the graph.

> >> IMO we should encourage people to use fetch+rebase instead of `pull',
> >
> > Why not "pull --rebase" instead?
> 
> Because people here work with at least two branches.

Who does?  The recommendation is not to do that, because master and
the release branch diverge very quickly, so switching branches will
almost always require a full bootstrap.

You are, of course, free to do that if you like, but then you probably
know what you are doing anyway.  In contrast, forcing the (at least
somewhat) confused majority to have yet another command in their
everyday workflow means more pain for them.

> With the right tool (Magit, for instance) fetch+rebase is faster than
> the command line (just type ffR) and you see at all times your changes,
> the fetched commits, the rebase status, etc.

We are talking about CLI commands here.  Emacs front ends are a
separate matter, they can simply automate everything, so people will
not have to remember the Git commands that run under the hood.  That's
not the issue at hand.

> >> (I'll not dare to ask why, mysteriously, the emacs-diffs mailing list
> >> abstained from mentioning my commit.)
> >
> > It didn't.  It's just that this is your first time, and emacs-diffs is
> > a moderated list, so I needed to approve your messages, just this
> > once.  Part of your welcome party, I guess.
> 
> I feel so especial today.

You are.  Welcome on board.