Git Mailing List Archive on lore.kernel.org
 help / color / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Arnaud Bertrand <xda@abalgo.com>
Cc: git@vger.kernel.org
Subject: Re: Mismatch meaning between git-diff and git-log for the .. (double dot notation) and ... (triple dot notation)
Date: Mon, 23 Dec 2019 10:02:31 -0800
Message-ID: <xmqqy2v26hu0.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <CAEW0o+gYqWT5u-Tf8aDoMgXaf36Mb-XOApLNs4D+GMVLvsOjxg@mail.gmail.com> (Arnaud Bertrand's message of "Mon, 23 Dec 2019 13:51:12 +0100")

Please unlearn dot-dot and three-dots when using "git diff", which
is not about ranges but about comparing two endpoints.  If we were
reinventing Git today from scratch, we would make "git diff A..B" an
error.  You can consider it a bug that the command accepts a range
notation, but this will not change any time soon without a large
fight to find and fix uses of the syntax in scripts by longtime Git
users have written over the years.

Allowing dot-dot on the command line of "git diff", instead of
diagnosing them as errors and dying, was a stupid mistake we (well,
mostly Linus, but I am willing to take the blame too) made due to
laziness when we reused the machinery, which we invented to parse
the command line of "log" family of commands to specify ranges, to
parse the command line of "diff", which accidentally ended up
allowing the syntax for ranges where it shouldn't be allowed.

And worse yet, since there was only dot-dot and three-dots came much
later, "git diff A..B" ended up comparing the endpoints A and B,
because there didn't even A...B notation exist.

This is not limited to you but any user of modern Git is better off
to pretend "git diff A..B" does not exist; please unlearn dot-dot
and three-dots when using "git diff" and you'd be happier.

  reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-23 12:51 Arnaud Bertrand
2019-12-23 18:02 ` Junio C Hamano [this message]
2019-12-23 18:29   ` Kevin Daudt
2019-12-23 21:59     ` Jonathan Nieder
2019-12-23 22:10     ` Junio C Hamano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqqy2v26hu0.fsf@gitster-ct.c.googlers.com \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=xda@abalgo.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Git Mailing List Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/git/0 git/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 git git/ https://lore.kernel.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.git


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git