From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C82C4C433E0 for ; Fri, 26 Jun 2020 21:33:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0D49212CC for ; Fri, 26 Jun 2020 21:33:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725912AbgFZVdS (ORCPT ); Fri, 26 Jun 2020 17:33:18 -0400 Received: from smtp.hosts.co.uk ([85.233.160.19]:12141 "EHLO smtp.hosts.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725780AbgFZVdS (ORCPT ); Fri, 26 Jun 2020 17:33:18 -0400 Received: from host-92-20-155-32.as13285.net ([92.20.155.32] helo=[192.168.1.37]) by smtp.hosts.co.uk with esmtpa (Exim) (envelope-from ) id 1jovyF-0004PT-Fn; Fri, 26 Jun 2020 22:33:16 +0100 Subject: Re: Regarding Git and Branch Naming To: Jeff King , Chris Torek Cc: Craig H Maynard , git@vger.kernel.org References:

<20200626203539.GA1173768@coredump.intra.peff.net> From: Philip Oakley Message-ID: <6b9d76e4-68dd-8e57-f96a-318579dea6f3@iee.email> Date: Fri, 26 Jun 2020 22:33:14 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200626203539.GA1173768@coredump.intra.peff.net> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-GB Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 26/06/2020 21:35, Jeff King wrote: > On Fri, Jun 26, 2020 at 11:33:53AM -0700, Chris Torek wrote: > >> On Fri, Jun 26, 2020 at 10:19 AM Craig H Maynard wrote: >>> Does the git init command really need to create a default branch? Perhaps that step could be left to the user. >> The HEAD pseudo-ref must exist and must contain a valid OID or >> branch name. (If it does not exist, Git says that the directory >> is not a repository. Perhaps this test could be weakened, but >> that's definitely a fairly big change.) >> >> In a new, empty repository there are no valid OIDs, so HEAD must >> contain a branch name. The branch itself need not exist, but >> whatever name is in HEAD is the branch that will be created >> when the user makes the first commit. > We definitely _could_ extend HEAD to allow a "not pointing at anything" > state. Presumably for reading that would behave like the "pointing at a > branch that doesn't exist yet" case. But I think the experience it > creates for writing is not very good. I.e., I think the best we could do > is something like: > > $ git init > $ git add some-files > $ git commit -m whatever > fatal: HEAD does not point to any branch > hint: use "git checkout -b " to make commits on > > Perhaps that's not _too_ bad, but it feels a bit unfriendly (and > definitely more likely to cause backwards compatibility issues than > picking _some_ default name). There would also be a lot of corner cases > to cover and debug (e.g., "git checkout foo" moving away from the "no > branch" state should make the usual complaints if we'd have to overwrite > or modify index and untracked files). > > A wild bikeshed question: Is HEAD itself protected as a branch name e.g. that HEAD could contain `ref: HEAD` or `ref: refs/heads/HEAD`? (or maybe the null oid It sort of feels that we may already have some sort of protection for the first self reference - i.e. exists, but not defined (self-reference). Philip