Re: [PATCH v2 02/14] pull: improve default warning

From: Felipe Contreras <felipe.contreras@gmail.com>
To: Elijah Newren <newren@gmail.com>
Cc: "Git Mailing List" <git@vger.kernel.org>,
	"Vít Ondruch" <vondruch@redhat.com>,
	"Alex Henrie" <alexhenrie24@gmail.com>,
	"Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
	"Philip Oakley" <philipoakley@iee.email>,
	"Theodore Y . Ts'o" <tytso@mit.edu>,
	"Jacob Keller" <jacob.keller@gmail.com>,
	"John Keeping" <john@keeping.me.uk>,
	"Richard Hansen" <rhansen@rhansen.org>,
	"Brian M. Carlson" <sandals@crustytoothpaste.net>,
	"W. Trevor King" <wking@tremily.us>
Subject: Re: [PATCH v2 02/14] pull: improve default warning
Date: Sun, 6 Dec 2020 08:31:41 -0600	[thread overview]
Message-ID: <CAMP44s2fCnjJSp2fzSq5is0LR6GDPP+wnM9r3kz=U65c7h_UPg@mail.gmail.com> (raw)
In-Reply-To: <CABPp-BGdNt8TBMTE9zvaicF5AtvyTBhpiJXqkuZc7mBLGbw0Qw@mail.gmail.com>

On Sat, Dec 5, 2020 at 7:01 PM Elijah Newren <newren@gmail.com> wrote:
>
> On Sat, Dec 5, 2020 at 1:28 PM Felipe Contreras
> <felipe.contreras@gmail.com> wrote:
> >
> > On Sat, Dec 5, 2020 at 10:28 AM Elijah Newren <newren@gmail.com> wrote:
> > > On Fri, Dec 4, 2020 at 5:56 PM Felipe Contreras
> > > <felipe.contreras@gmail.com> wrote:
> >
> > > > Well, I already said I partly agree with you: in the --ff-only case
> > > > the suggestion should not be brought forward.
> > > >
> > > > But in the "git pull" default case, *today* it's doing a merge. If
> > > > uttering --merge and thus making the current behavior explicit instead
> > > > of implicit seems dangerous it's because it is. But not documenting it
> > > > doesn't make it any less dangerous.
> > >
> > > Sounds like we agree that the future should be ff-only-as-default.  I
> > > also agree with you that the primary problem is the current default
> > > behavior, and I'll agree with you that documenting the current default
> > > is okay.  However, I disagree that your wording here:
> > >
> > > +                       "If unsure, run \"git pull --no-rebase\".\n"
> > >
> > > does anything of the sort.  It does not mention that this is the
> > > default behavior the users would get if they provided no flags.
> >
> > But that is not the warning, this is the warning:
> >
> >   Pulling without specifying how to reconcile divergent branches is discouraged;
> >   you need to specify if you want a merge, a rebase, or a fast-forward.
> >   You can squelch this message by running one of the following commands:
> >
> >     git config pull.rebase false  # merge (the default strategy)
> >     git config pull.rebase true   # rebase
> >     git config pull.ff only       # fast-forward only
> >
> >   You can replace "git config" with "git config --global" to set a default
> >   preference for all repositories.
> >   If unsure, run "git pull --merge".
> >   Read "git pull --help" for more information.
> >
> > This warning says:
> >
> > 1. There's 3 options: merge, rebase, fast-forward
> > 2. merge is the default strategy
> > 3. If unsure, specify --merge (the default strategy)
> >
> > So taken altogether it does say what is the default strategy.
>
> We don't need to take them together.

No, but that's what I'm proposing.

> #2 by itself states the default strategy.

Yes, with configuration, not with commands.

> I don't see why defending #3 as being for the purpose of
> documenting the default strategy is helpful, since it doesn't do that.

I disagree. It does do that, but it serves a more urgent purpose: it
tells the user how to ignore us quickly, for now.

> > The current warning should not exist at all.
> >
> > The complaint from Vít Ondruch [1] that reignited this series is a
> > valid one. A *permanent* warning is not good. We should have a
> > *temporary* warning with the express purpose of notifying users of an
> > upcoming change.
> >
> > If we have not yet decided on what should be the default (Junio seems
> > to have casted some doubt on the consensus [2]), and we don't have a
>
> Useful link there.  Based on his comments, we may want to make
> --ff-only, --merge, and --rebase all be mutually exclusive and result
> in an error message if more than one is specified at the command line.
> (But still have the command line countermand any option set in the
> config, of course).

Yes, but that's a change in behavior.

Moreover, what do you suggest this should do?

  git -c "pull.rebase=true" -c "pull.ff=only" pull

I have already tried to make pull.ff=only work in several ways. It's
just not a clean solution.

Cheers.

-- 
Felipe Contreras