git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: Thomas Gummerer <t.gummerer@gmail.com>,
	Git Mailing List <git@vger.kernel.org>,
	"brian m. carlson" <sandals@crustytoothpaste.ath.cx>
Subject: Re: [PATCH] refs: make sure we never pass NULL to hashcpy
Date: Sat, 09 Sep 2017 02:15:51 +0900	[thread overview]
Message-ID: <xmqqfubxyuuw.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <ab0c4064-6eaa-c298-a26d-58fc83e4574f@alum.mit.edu> (Michael Haggerty's message of "Fri, 8 Sep 2017 17:08:17 +0200")

Michael Haggerty <mhagger@alum.mit.edu> writes:

> So `ref_transaction_update()` *does* need to set or clear the `HAVE_NEW`
> and `HAVE_OLD` bits as I sketched, to impedance-match between the two
> conventions.

OK, so ignoring HAVE_NEW/HAVE_OLD bits that the callers of
ref_transaction_update() may set in flags, and having
ref_transaction_update() compute these bits based on new/old_sha1
pointers from scratch, would be the right thing to do.

IOW

	flags &= ~(REF_HAVE_NEW|REF_HAVE_OLD);
	if (new_sha1)
		flags |= REF_HAVE_NEW;
	if (old_sha1)
		flags |= REF_HAVE_OLD;

and your earlier "Does the warning go away if you change the line
to" does essentially the same thing.

> It's a shame how much time we've wasted discussing this. Maybe the code
> is trying to be too clever/efficient and needs a rethink.

It might be the case, but I do not know what to blame is "the two
conventions", an over-eager compiler, or a confused commenter on the
thread (that's me), though ;-).

  reply	other threads:[~2017-09-08 17:15 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-04 20:05 [PATCH] refs: make sure we never pass NULL to hashcpy Thomas Gummerer
2017-09-06  1:26 ` Junio C Hamano
2017-09-06 20:32   ` Thomas Gummerer
2017-09-07  7:26   ` Michael Haggerty
2017-09-07 20:39     ` Thomas Gummerer
2017-09-08  0:46     ` Junio C Hamano
2017-09-08 15:08       ` Michael Haggerty
2017-09-08 17:15         ` Junio C Hamano [this message]
2017-09-12 22:59     ` [RFC v2] refs: strip out not allowed flags from ref_transaction_update Thomas Gummerer
2017-09-21  8:40       ` Michael Haggerty
2017-09-22  4:23         ` Junio C Hamano
2017-09-24 20:45         ` Thomas Gummerer

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

  List information: http://vger.kernel.org/majordomo-info.html

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

  git send-email \
    --in-reply-to=xmqqfubxyuuw.fsf@gitster.mtv.corp.google.com \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=mhagger@alum.mit.edu \
    --cc=sandals@crustytoothpaste.ath.cx \
    --cc=t.gummerer@gmail.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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).