From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#4422: diff-switches is a bad idea Date: Tue, 01 Oct 2019 16:42:14 +0300 Message-ID: <83h84sa8g9.fsf@gnu.org> References: <87d0fg7gey.fsf@gnus.org> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="105845"; mail-complaints-to="usenet@blaine.gmane.org" Cc: 4422@debbugs.gnu.org, rrt@sc3d.org To: Lars Ingebrigtsen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Oct 01 15:45:09 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iFISj-000REG-1e for geb-bug-gnu-emacs@m.gmane.org; Tue, 01 Oct 2019 15:45:09 +0200 Original-Received: from localhost ([::1]:42318 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iFISh-0006vf-Np for geb-bug-gnu-emacs@m.gmane.org; Tue, 01 Oct 2019 09:45:07 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:59375) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iFIQi-0005BX-3J for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 09:43:05 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iFIQh-0006ya-0l for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 09:43:04 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:52318) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iFIQg-0006yM-Tq for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 09:43:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iFIQg-0001ON-R3 for bug-gnu-emacs@gnu.org; Tue, 01 Oct 2019 09:43:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 01 Oct 2019 13:43:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 4422 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: moreinfo Original-Received: via spool by 4422-submit@debbugs.gnu.org id=B4422.15699373425281 (code B ref 4422); Tue, 01 Oct 2019 13:43:02 +0000 Original-Received: (at 4422) by debbugs.gnu.org; 1 Oct 2019 13:42:22 +0000 Original-Received: from localhost ([127.0.0.1]:32904 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iFIQ2-0001N7-4L for submit@debbugs.gnu.org; Tue, 01 Oct 2019 09:42:22 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:50216) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iFIQ0-0001Mt-BT for 4422@debbugs.gnu.org; Tue, 01 Oct 2019 09:42:20 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:33259) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iFIPu-0006Mt-W5; Tue, 01 Oct 2019 09:42:15 -0400 Original-Received: from [176.228.60.248] (port=4338 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iFIPu-0003Fp-8d; Tue, 01 Oct 2019 09:42:14 -0400 In-reply-to: <87d0fg7gey.fsf@gnus.org> (message from Lars Ingebrigtsen on Tue, 01 Oct 2019 15:18:29 +0200) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:168000 Archived-At: > From: Lars Ingebrigtsen > Date: Tue, 01 Oct 2019 15:18:29 +0200 > Cc: 4422@debbugs.gnu.org > > Reuben Thomas writes: > > > I'm using Emacs 23, and I have just been puzzling over why vc-diff > > stopped working in CVS checkouts. I eventually traced it to > > diff-switches: I have mine set to "-Nur", quite reasonably, I think, > > but of course "-r" means something quite different to CVS, and I ended > > up with a hard-to-understand error message about tags. > > > > I suggest not using diff-switches (this would also remove some > > special-case code, as no other vc command respects a non-vc option > > like this.) Yes, some users will have to configure the same thing in > > two places, but others will be saved the confusion I had. For the > > switches to be commoned up sensibly, a more structured approach to > > setting them is needed that takes semantics into account, and that way > > lies madness. > > (I'm going through old bug reports that unfortunately didn't get any > response at the time.) > > I'm not extremely familiar with the vc code, but looking at it in Emacs > 27, at least, the switches for diff in CVS comes from > vc-cvs-diff-switches, if I read the `vc-switches' function correctly. It uses vc-cvs-diff-switches, but if that's nil (the default), it will try to use vc-diff-switches (which is also nil by default) and diff-switches, using the first non-nil of these. I think the current situation is reasonable, since to resolve it the user could customize vc-diff-switches or vc-cvs-diff-switches to t to avoid this problem.