From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Haggerty Subject: Re: Bug: "git checkout -b" should be allowed in empty repo Date: Tue, 31 Jan 2012 09:57:17 +0100 Message-ID: <4F27ACED.2050709@alum.mit.edu> References: <4F24E287.3040302@alum.mit.edu> <7vwr8bvvxj.fsf@alter.siamese.dyndns.org> <4F263AEE.4080409@alum.mit.edu> <7v39axc9gp.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org To: Junio C Hamano X-From: git-owner@vger.kernel.org Tue Jan 31 09:57:57 2012 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 1Rs9XI-0000hp-4w for gcvg-git-2@plane.gmane.org; Tue, 31 Jan 2012 09:57:56 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753400Ab2AaI5p (ORCPT ); Tue, 31 Jan 2012 03:57:45 -0500 Received: from einhorn.in-berlin.de ([192.109.42.8]:57883 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753360Ab2AaI5p (ORCPT ); Tue, 31 Jan 2012 03:57:45 -0500 X-Envelope-From: mhagger@alum.mit.edu Received: from [192.168.100.152] (ssh.berlin.jpk.com [212.222.128.135]) (authenticated bits=0) by einhorn.in-berlin.de (8.13.6/8.13.6/Debian-1) with ESMTP id q0V8vIga025441 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Tue, 31 Jan 2012 09:57:18 +0100 User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.24) Gecko/20111108 Lightning/1.0b2 Thunderbird/3.1.16 In-Reply-To: <7v39axc9gp.fsf@alter.siamese.dyndns.org> X-Scanned-By: MIMEDefang_at_IN-Berlin_e.V. on 192.109.42.8 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On 01/30/2012 07:48 PM, Junio C Hamano wrote: > Michael Haggerty writes: > >> [3] If commit 0000000 were treated specially, then there would be no >> unborn branches but only branches pointing at the empty commit. In that >> case, my expectation would change--the old branch should be left >> pointing at 0000000. But currently git has no concept of an unborn >> branch that is not HEAD. > > And it probably is not a good thing to add such. Under that constraints, > HEAD that says refs/heads/foo where foo does not exist yet needs to be > special cased at places where it matters. > > For that matter, even if we artificially created refs/heads/foo before any > commit is made and made it point at 0{40}, you would need to add special > cases to other parts of the system No, the idea is to avoid special casing by making 0{40} into a real (but empty) revision. > (e.g. "commit" needs to notice that the > result should be a root, not a child of 0{40}; No, commits that were previously generated as orphans *would* now be generated as children of the special 0{40} commit. > "checkout other_branch" > needs to notice that it should refrain from running the equivalent of > "read-tree -m HEAD other_branch" because HEAD does not point at a real > tree; No, it would merge the 0{40} commit with other_branch like usual, resulting in the same contents as other_branch. Indeed, if other_branch is also ultimately a descendant of 0{40}, this would be like a fast-forward merge. > etc. This "etc" might include problems. > so it does not change the fact that the unborn branch is case > is special. On the contrary, I believe that much special casing could be eliminated and the UI made more uniform by treating everything as a descendant of a special "NULL" commit. Michael -- Michael Haggerty mhagger@alum.mit.edu http://softwareswirl.blogspot.com/