From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8246 invoked by alias); 26 Dec 2019 22:57:18 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 8229 invoked by uid 89); 26 Dec 2019 22:57:17 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-0.6 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.1 spammy=committers, chosen, HContent-Transfer-Encoding:8bit X-HELO: joooj.vinc17.net Received: from joooj.vinc17.net (HELO joooj.vinc17.net) (155.133.131.76) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 26 Dec 2019 22:57:15 +0000 Received: from smtp-zira.vinc17.net (jlefevre.net1.nerim.net [80.65.226.245]) by joooj.vinc17.net (Postfix) with ESMTPSA id 108D32FF; Thu, 26 Dec 2019 23:57:11 +0100 (CET) Received: by zira.vinc17.org (Postfix, from userid 1000) id 2F8A4C20346; Thu, 26 Dec 2019 23:57:08 +0100 (CET) Date: Thu, 26 Dec 2019 22:57:00 -0000 From: Vincent Lefevre To: gcc@gcc.gnu.org Subject: Re: Test GCC conversion with reposurgeon available Message-ID: <20191226225708.GB1343365@zira.vinc17.org> Mail-Followup-To: gcc@gcc.gnu.org References: <20191224181444.GJ4505@gate.crashing.org> <279bf8dd-8725-c3fa-0def-130b3d128509@ispras.ru> <871rssiigs.fsf@hase.home> <87woakh25b.fsf@hase.home> <20191225171536.GN4505@gate.crashing.org> <20191225193345.GC19267@thyrsus.com> <20191226210334.GA1343365@zira.vinc17.org> <20191226213015.GB116941@thyrsus.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191226213015.GB116941@thyrsus.com> X-Mailer-Info: https://www.vinc17.net/mutt/ User-Agent: Mutt/1.12.1+33 (6a74e24e) vl-117499 (2019-06-23) X-IsSubscribed: yes X-SW-Source: 2019-12/txt/msg00436.txt.bz2 On 2019-12-26 16:30:15 -0500, Eric S. Raymond wrote: > Vincent Lefevre : > > > Here's why you want to get timezones right: there are going to be times > > > when the order of commits is significant information for a developer's > > > understanding of what happened. But without a timezone you only know > > > the actual time of a commit to 24-hour resoltion. > > > > I don't understand what you mean. What matters for the order of > > commits is the global time, and this is what SVN stores. SVN does not > > store timezone information, i.e. it has no idea of what local time of > > the user had, but I don't think this is important information. > > UTC time plus a timezone offset set is what git stores. That's not the > locus of the problem. > > In Subversion-land there's newver any doubt about the sequence of commits; > the revision numbers tell you that. In Git-land you have to go by timestamps, > and if a timezone entry is wrong it can skew the displayed time. What matters is that the date is correct. I don't think the timezone matters (that's why SVN doesn't store timezone information, I assume), possibly except for the committer himself (?). For instance, 2019-11-27 02:32:02 +0100 and 2019-11-27 01:32:02 +0000 correspond to the same date. So, each one (as stored in the repository) is fine if you want to be able to know the order of commits. What is displayed then is actually a user-config issue. The conversion utility can't solve this issue, since after conversion, committers will be able to use any timezone they like. > Me, I don't undertstand why version-control systems designed for distributed > use don't ignore timezones entirely and display all times in UTC - relative > time is surely more imoortant than the commit time's relationship to solar > noon wherever the keyboard happened to be. But I don't make these decisions. I agree, at least being able to display all times in a *fixed* timezone (chosen by the user), as this could be easier for the user to know when recent commits occur (by "recent", this can be less than 24 hours ago). For UTC, you can use: TZ=UTC git log --date=iso-local The date format can be stored in ~/.gitconfig, but unfortunately not local timezone information. In this case, the timezones of the commits chosen by the conversion utility will not matter at all. -- Vincent Lefèvre - Web: 100% accessible validated (X)HTML - Blog: Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)