From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Hommey Subject: Re: Consistency question Date: Sat, 18 Jan 2014 10:22:22 +0900 Message-ID: <20140118012222.GA4381@glandium.org> References: <8761pl8raj.fsf@fencepost.gnu.org> <20140115111330.GH14335@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Kastrup , git@vger.kernel.org To: Jeff King X-From: git-owner@vger.kernel.org Sat Jan 18 02:22:47 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1W4KcY-0003MF-5Z for gcvg-git-2@plane.gmane.org; Sat, 18 Jan 2014 02:22:46 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbaARBWn (ORCPT ); Fri, 17 Jan 2014 20:22:43 -0500 Received: from ks3293202.kimsufi.com ([5.135.186.141]:58692 "EHLO jigen.glandium.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752803AbaARBWl (ORCPT ); Fri, 17 Jan 2014 20:22:41 -0500 Received: from mh by jigen.glandium.org with local (Exim 4.82) (envelope-from ) id 1W4KcA-0001Ct-SH; Sat, 18 Jan 2014 10:22:22 +0900 Content-Disposition: inline In-Reply-To: <20140115111330.GH14335@sigill.intra.peff.net> X-GPG-Fingerprint: 182E 161D 1130 B9FC CD7D B167 E42A A04F A6AA 8C72 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Wed, Jan 15, 2014 at 06:13:30AM -0500, Jeff King wrote: > On Wed, Jan 15, 2014 at 11:37:08AM +0100, David Kastrup wrote: > > > The question is what guarantees I have with regard to the commit date of > > a commit in relation to that of its parent commits: > > > > a) none > > b) commitdate(child) >= commitdate(parent) > > c) commitdate(child) > commitdate(parent) > > a) none > > > Obviously, I can rely on c) being true "almost always": > > Actually, b) is quite often the case in automated processes (e.g., "git > am" or "git rebase"). The author dates are different, but the committer > dates may be in the same second. > > And of course a) is the result of clock skew and software bugs. ... or importing non-git repositories that don't have commit info separated from author info like git does. In such cases, it's usual to duplicate the author info as commit info so that clones of the same non-git repo end up with the same git sha1s. Mercurial easily allows author dates to be in a non topological order. Mike