From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.1 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 693EE201B0 for ; Tue, 28 Feb 2017 13:53:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752029AbdB1NxS (ORCPT ); Tue, 28 Feb 2017 08:53:18 -0500 Received: from cloud.peff.net ([104.130.231.41]:35637 "EHLO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751986AbdB1NxR (ORCPT ); Tue, 28 Feb 2017 08:53:17 -0500 Received: (qmail 21948 invoked by uid 109); 28 Feb 2017 12:06:35 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.84) with SMTP; Tue, 28 Feb 2017 12:06:35 +0000 Received: (qmail 25302 invoked by uid 111); 28 Feb 2017 12:06:41 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.84) with SMTP; Tue, 28 Feb 2017 07:06:41 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 28 Feb 2017 07:06:33 -0500 Date: Tue, 28 Feb 2017 07:06:33 -0500 From: Jeff King To: Junio C Hamano Cc: Jacob Keller , Karthik Nayak , Luc Van Oostenryck , Git List Subject: Re: [BUG] branch renamed to 'HEAD' Message-ID: <20170228120633.zkwfqms57fk7dkl5@sigill.intra.peff.net> References: <20170227045257.yazqlrqlnggosi5t@macbook.local> <20170227074915.xljfe5jox756rlyv@sigill.intra.peff.net> <20170227080158.de2xarctzscfdsp2@sigill.intra.peff.net> <20170227090233.uk7dfruggytgmuw2@sigill.intra.peff.net> <20170228005302.k6fyfinaxyl3ti76@sigill.intra.peff.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170228005302.k6fyfinaxyl3ti76@sigill.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Feb 27, 2017 at 07:53:02PM -0500, Jeff King wrote: > On Mon, Feb 27, 2017 at 04:33:36PM -0800, Junio C Hamano wrote: > > > A flag to affect the behaviour (as opposed to &flag as a secondary > > return value, like Peff's patch does) can be made to work. Perhaps > > a flag that says "keep the input as is if the result is not a local > > branch name" would pass an input "@" intact and that may be > > sufficient to allow "git branch -m @" to rename the current branch > > to "@" (I do not think it is a sensible rename, though ;-). But > > probably some callers need to keep the original input and compare > > with the result to see if we expanded anything if we go that route. > > At that point, I am not sure if there are much differences in the > > ease of use between the two approaches. > > I just went into more detail in my reply to Jacob, but I do think this > is a workable approach (and fortunately we seem to have banned bare "@" > as a name, along with anything containing "@{}", so I think we would end > up rejecting these nonsense names). > > I'll see if I can work up a patch. We'll still need to pass the flag > around through the various functions, but at least it will be a flag and > not a confusing negated out-parameter. OK, I have a series which fixes this (diffstat below). When I audited the other callers of interpret_branch_name() and strbuf_branchname(), it turned out to be even more complicated. The callers basically fall into a few buckets: 1. Callers like get_sha1() and merge_name() pass the result to dwim_ref(), and are prepared to handle anything. 2. Some callers stick "refs/heads/" in front of the result, and obviously only want local names. Most of git-branch and git-checkout fall into this boat. 3. "git branch -d" can delete local _or_ remote branches, depending on the "-r" flag. So the expansion it wants varies, and we need to handle "just local" or "just remote". So I converted the "only_branch" flag to an "allowed" bit-field. No callers actually ask for more than a single type at once, but it was easy to do it that way. It serves all of the callers, and will easily adapt for the future (e.g., if "git branch -a -d" were ever allowed). [1/8]: interpret_branch_name: move docstring to header file [2/8]: strbuf_branchname: drop return value [3/8]: strbuf_branchname: add docstring [4/8]: interpret_branch_name: allow callers to restrict expansions [5/8]: t3204: test git-branch @-expansion corner cases [6/8]: branch: restrict @-expansions when deleting [7/8]: strbuf_check_ref_format(): expand only local branches [8/8]: checkout: restrict @-expansions when finding branch builtin/branch.c | 5 +- builtin/checkout.c | 2 +- builtin/merge.c | 2 +- cache.h | 32 ++++++++- refs.c | 2 +- revision.c | 2 +- sha1_name.c | 76 ++++++++++----------- strbuf.h | 21 +++++- t/t3204-branch-name-interpretation.sh | 122 ++++++++++++++++++++++++++++++++++ 9 files changed, 220 insertions(+), 44 deletions(-) create mode 100755 t/t3204-branch-name-interpretation.sh -Peff