From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 287981F453 for ; Sun, 3 Feb 2019 23:01:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727636AbfBCXB6 (ORCPT ); Sun, 3 Feb 2019 18:01:58 -0500 Received: from cloud.peff.net ([104.130.231.41]:59602 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726554AbfBCXB6 (ORCPT ); Sun, 3 Feb 2019 18:01:58 -0500 Received: (qmail 2527 invoked by uid 109); 3 Feb 2019 23:01:58 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Sun, 03 Feb 2019 23:01:58 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 16098 invoked by uid 111); 3 Feb 2019 23:02:05 -0000 Received: from Unknown (HELO sigill.intra.peff.net) (10.0.1.7) by peff.net (qpsmtpd/0.94) with (ECDHE-RSA-AES256-GCM-SHA384 encrypted) SMTP; Sun, 03 Feb 2019 18:02:05 -0500 Authentication-Results: peff.net; auth=none Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Mon, 04 Feb 2019 00:01:53 +0100 Date: Mon, 4 Feb 2019 00:01:53 +0100 From: Jeff King To: Martin =?utf-8?B?w4VncmVu?= Cc: git@vger.kernel.org, Eric Sunshine Subject: Re: [PATCH v2] doc-diff: don't `cd_to_toplevel` before calling `usage` Message-ID: <20190203230152.GA25608@sigill.intra.peff.net> References: <20190203110817.17242-1-martin.agren@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190203110817.17242-1-martin.agren@gmail.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Sun, Feb 03, 2019 at 12:08:17PM +0100, Martin Ågren wrote: > `usage` tries to call $0, which might very well be "./doc-diff", so if > we `cd_to_toplevel` before calling `usage`, we'll end with an error to > the effect of "./doc-diff: not found" rather than a friendly `doc-diff > -h` output. Granted, all of these `usage` calls are in error paths, so > we're about to exit anyway, but the user experience of something like > `(cd Documentation && ./doc-diff)` could be a bit better than > "./doc-diff: not found". > > This regressed in ad51743007 ("doc-diff: add --clean mode to remove > temporary working gunk", 2018-08-31) where we moved the call to > `cd_to_toplevel` to much earlier. Move it back to where it was, and > teach the "--clean" code to cd on its own. This way, we only cd once > we've verified the arguments. > > A more general fix would be to teach git-sh-setup to save away the > absolute path for $0 and then use that, instead. I'm not aware of any > portable way of doing that, see, e.g., d2addc3b96 ("t7800: readlink > may not be available", 2016-05-31), so let's just fix this user > instead. This (and the patch) seems quite reasonable as a fix. I actually think we could go further and drop the cd_to_toplevel entirely. IIRC, the only thing it accomplishes[1] is that we can consistently refer to the tmp directory as Documentation/tmp-doc-diff. It would probably be fine to: - use "$(git rev-parse --show-toplevel)/Documentation/tmp-doc-diff". In earlier iterations of the script, I think using an absolute path bled through to the resulting diff, but we later cleaned that up anyway. - just use a relative "tmp-doc-diff". I doubt anybody actually wants to do anything other than "cd Documentation && ./doc-diff" anyway. This breaks "./Documentation/doc-diff", but it is not like you can run "t/t0000-basic.sh" either. -Peff [1] I think also in early iterations I had some notion of using the cwd to build things, but that quickly went out the window in favor of worktrees.