From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: [FIXED PATCH] Make rebase save ORIG_HEAD if changing current branch Date: Sun, 06 Jul 2008 23:28:36 -0700 Message-ID: <7vbq1a8ay3.fsf@gitster.siamese.dyndns.org> References: <1215379370-34265-1-git-send-email-benji@silverinsanity.com> <7v7iby9ucx.fsf@gitster.siamese.dyndns.org> <803A3528-2451-4C5D-A48D-5E0C37B8E90E@silverinsanity.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Git List To: Brian Gernhardt X-From: git-owner@vger.kernel.org Mon Jul 07 08:29:56 2008 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1KFkEJ-0001SR-6K for gcvg-git-2@gmane.org; Mon, 07 Jul 2008 08:29:43 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751460AbYGGG2p (ORCPT ); Mon, 7 Jul 2008 02:28:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751457AbYGGG2p (ORCPT ); Mon, 7 Jul 2008 02:28:45 -0400 Received: from a-sasl-fastnet.sasl.smtp.pobox.com ([207.106.133.19]:46970 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751380AbYGGG2p (ORCPT ); Mon, 7 Jul 2008 02:28:45 -0400 Received: from localhost.localdomain (localhost [127.0.0.1]) by a-sasl-fastnet.sasl.smtp.pobox.com (Postfix) with ESMTP id 13B0110BCF; Mon, 7 Jul 2008 02:28:44 -0400 (EDT) Received: from pobox.com (ip68-225-240-77.oc.oc.cox.net [68.225.240.77]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-sasl-fastnet.sasl.smtp.pobox.com (Postfix) with ESMTPSA id 6B4F610BCE; Mon, 7 Jul 2008 02:28:38 -0400 (EDT) In-Reply-To: <803A3528-2451-4C5D-A48D-5E0C37B8E90E@silverinsanity.com> (Brian Gernhardt's message of "Mon, 7 Jul 2008 01:16:06 -0400") User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) X-Pobox-Relay-ID: F29CEB12-4BED-11DD-B776-CE28B26B55AE-77302942!a-sasl-fastnet.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Brian Gernhardt writes: > My final thought is that the rational ORIG_HEAD and when we set it is > not clearly documented anywhere. But I am currently out of time to > work on git, so that patch won't be coming from me soon. The idea behind ORIG_HEAD is to have an anchoring point before an operation that moves your HEAD in a drastic way. Think if it as a poor-man's reflog -- in fact it predates reflog. That is why reset saves away the HEAD before it does its thing, so that you can easily say "Oops, I did not mean it -- reset ORIG_HEAD" to flip back to the previous state. Both a fast-forward merge and a real merge can be undone by resetting back to ORIG_HEAD. So in that sense: (1) ORIG_HEAD is not strictly necessary these days, because we have reflogs; (2) Even then, it is handy and useful, and we could add ORIG_HEAD to more commands such as "git am" and "git rebase".