From: Felipe Contreras <felipe.contreras@gmail.com>
To: Junio C Hamano <gitster@pobox.com>,
Matthieu Moy <Matthieu.Moy@univ-lyon1.fr>
Cc: Sergey Organov <sorganov@gmail.com>,
Felipe Contreras <felipe.contreras@gmail.com>,
"git@vger.kernel.org" <git@vger.kernel.org>
Subject: Re: Can we clarify the purpose of `git diff -s`?
Date: Fri, 12 May 2023 13:34:43 -0600 [thread overview]
Message-ID: <645e94d38510f_21989f294c6@chronos.notmuch> (raw)
In-Reply-To: <xmqqo7mpqy6g.fsf@gitster.g>
Junio C Hamano wrote:
> Matthieu Moy <Matthieu.Moy@univ-lyon1.fr> writes:
>
> > https://public-inbox.org/git/51E3DC47.70107@googlemail.com/
> >
> > Essentially, Stefan Beller was using 'git show --format="%ad"' and
> > expecting it to show only the author date, and for merge commits it
> > also showed the patch (--cc). I suggested -s and noticed that the
> > option wasn't easily discoverable, hence the patch series to better
> > document it and add --no-patch as a synonym.
> >
> > Probably I did not get all the subtleties of the different kinds of
> > outputs. I guess I considered the output of diff to be the one
> > specified by --format plus the patch (not considering --raw, --stat &
> > friends), hence "get only the output specified by --format" and
> > "disable the patch" were synonym to me.
>
> Thanks for double checking. It matches my recollection that we (you
> the author and other reviewers as well) added "--no-patch" back then
> to mean "no output from diff machinery, exactly the same as '-s' but
> use a name that is more discoverable".
>
> > Looking more closely, it's
> > rather clear to me they are not, and that
> >
> > git show --raw --patch --no-patch
> >
> > should be equivalent to
> >
> > git show --raw
>
> Yeah. If this were 10 years ago and we were designing from scratch,
> the "no output from diff machinery, more discoverable alias for
> '-s'" would have been "--silent" or "--squelch" and we would made
> any "--no-<format>" to defeat only "--<format>".
>
> It is a different matter if we can safely change what "--no-patch"
> means _now_.
We can. As we have been able to do backwards-incompatible changes in the past,
will keep doing in the future.
You yourself proposed a backwards-incompatible change here [1].
> Given that "--no-patch" was introduced for the explicit purpose of giving
> "-s" a name that is easier to remember, and given that in the 10 years since
> we did so, we may have acquired at least a few more end users of Git than we
> used to have, hopefully your change have helped them discover and learn to
> use "--no-patch" to defeat any "--<format>" they gave earlier as initial
> options in their script, which will be broken and need to be updated to use a
> much less discoverable "-s".
That is not true.
`--no-patch` is not used to defeat any `--<format>`, it's used to disable
output, for example this:
git show --no-patch
There is zero point in writing:
git show --patch --no-patch
Because `--patch` is already the default.
But all of these would keep working fine if we change the semantics of
`--no-patch`.
It's not true that they will be broken.
It's only when the default is a format other than patch, or a format other than
patch is explicitely specified, for example:
git diff-files --no-patch
git show --raw --no-patch
Potentially the number of users who actually do this is *zero*.
A few users for some reason may have come to rely on the above behavior, but a
few users might have come to rely on the following behavior as well:
git show -s --raw
Which your patch [1] breaks.
[1] https://lore.kernel.org/git/20230505165952.335256-1-gitster@pobox.com/
--
Felipe Contreras
next prev parent reply other threads:[~2023-05-12 19:34 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-11 3:14 Can we clarify the purpose of `git diff -s`? Felipe Contreras
2023-05-11 11:59 ` Sergey Organov
2023-05-11 16:26 ` Junio C Hamano
2023-05-11 17:37 ` Junio C Hamano
2023-05-11 18:04 ` Sergey Organov
2023-05-11 18:27 ` Junio C Hamano
2023-05-11 18:36 ` Felipe Contreras
2023-05-11 18:17 ` Felipe Contreras
2023-05-11 17:41 ` Felipe Contreras
2023-05-11 18:31 ` Sergey Organov
2023-05-11 19:10 ` Felipe Contreras
2023-05-11 19:32 ` Sergey Organov
2023-05-11 19:54 ` Felipe Contreras
2023-05-11 20:24 ` Sergey Organov
2023-05-11 20:59 ` Felipe Contreras
2023-05-11 22:49 ` Sergey Organov
2023-05-11 23:28 ` Felipe Contreras
2023-05-12 8:40 ` Sergey Organov
2023-05-12 19:19 ` Felipe Contreras
[not found] ` <5bb24e0208dd4a8ca5f6697d578f3ae0@SAMBXP02.univ-lyon1.fr>
2023-05-12 8:15 ` Matthieu Moy
2023-05-12 17:03 ` Junio C Hamano
2023-05-12 18:21 ` Sergey Organov
2023-05-12 19:21 ` Junio C Hamano
2023-05-12 19:34 ` Junio C Hamano
2023-05-12 20:28 ` Felipe Contreras
2023-05-12 20:47 ` Junio C Hamano
2023-05-12 21:01 ` Felipe Contreras
2023-05-12 21:47 ` Junio C Hamano
2023-05-12 21:48 ` Junio C Hamano
2023-05-12 23:21 ` Felipe Contreras
2023-05-12 21:41 ` Sergey Organov
2023-05-12 22:17 ` Junio C Hamano
2023-05-12 22:47 ` Sergey Organov
2023-05-12 23:07 ` Felipe Contreras
2023-05-13 14:58 ` Philip Oakley
2023-05-13 17:45 ` Sergey Organov
2023-05-12 19:47 ` Felipe Contreras
2023-05-12 19:34 ` Felipe Contreras [this message]
2023-05-12 19:17 ` Felipe Contreras
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