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=-11.4 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,T_DKIMWL_WL_MED,USER_IN_DEF_DKIM_WL 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 48C211F42D for ; Tue, 29 May 2018 18:20:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937000AbeE2SUK (ORCPT ); Tue, 29 May 2018 14:20:10 -0400 Received: from mail-yw0-f173.google.com ([209.85.161.173]:38911 "EHLO mail-yw0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966037AbeE2STJ (ORCPT ); Tue, 29 May 2018 14:19:09 -0400 Received: by mail-yw0-f173.google.com with SMTP id y123-v6so5129393ywa.5 for ; Tue, 29 May 2018 11:19:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=NSRQiuP47fODSunI6A3sW/Q+heWOE3u9ajkhhV3qCO4=; b=e3LBdU+o0mBDfld4lDS6lNkxcX0GrZEiQ0rCphD5E+jKbNUPNu0qr7eqRJU3Uqbptz j11+kckeOPwWEgwSqEwu6Va7lWUUx8gi38uifea7RYVpOHCyG7ZFzurw1eGUcWI75aTP mAJdwpDnAyJbbooQIzN1KVQLzewH0KciOzOliqS6M8aHWKsqvDoZKeLRr1PaCglKOFC1 TY19hgJP6AFvbF+eZpI7C5Ub0ezY6SaOXmhfMUfKD0PMcH6tpZSWnuqjJDW9b7C0ODDX k0MKwFDQOYqgVw9Ti4NZ3FAj/YOjcDSS/+XouW+/d3dxgZGngAHCfEfVXsEU6hzOGAQe XiXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=NSRQiuP47fODSunI6A3sW/Q+heWOE3u9ajkhhV3qCO4=; b=fVWuRsPFsacSb4XI6eMtYMOjU37X+p9AvrAhS2DkkRjdaV6Jdrr6ndQcslckQpr1H+ CPfJ/WGCyAEsN92w1gQRpnm1lsWFwriwxKOycQNi5HS725VBR2IQGcBT0VfJK49fGlEJ bwy2xgVfrsNvK/QXvn9AS8IgjvU8Z6wrbSSGJJmkQ2uyvkQl+mfLG17zL63aBqdEaGz0 AwFTSqq5EmyVnqJYnKuNZQDytbOB4tn50gOlsL+Ck4yxTgdgkhH3yYwDxuaQBSuPJ9P+ XC2gBE56SKzvh/lH3HDejVJRHb1ZXno8HIPtgTdkG9Zy+qJ5jPgN7pIWPxulLQ7xl+kg 4cIg== X-Gm-Message-State: ALKqPweaePGHA0Wmge8wVFb4SXeokcaIY8loYhQa2PQtKOpIQNSZuBbr BhDrEwEBzdLQ+uKFMbWQ4HfDayWDpC11/tlEmlDOMA== X-Google-Smtp-Source: ADUXVKKaLunCMJYIwMKdwgaejESGRnjjWnIoM/cc8UyGHMclwY8MkEPW6jlqIiTZRc+eDJUteJpIa37vb0BxMiZIdvQ= X-Received: by 2002:a81:9447:: with SMTP id l68-v6mr2917704ywg.345.1527617948544; Tue, 29 May 2018 11:19:08 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a25:e87:0:0:0:0:0 with HTTP; Tue, 29 May 2018 11:19:07 -0700 (PDT) In-Reply-To: References: From: Stefan Beller Date: Tue, 29 May 2018 11:19:07 -0700 Message-ID: Subject: Re: RFC: Merge-related plans To: Elijah Newren Cc: Git Mailing List Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, May 28, 2018 at 1:48 PM, Elijah Newren wrote: > Hi everyone, > > I have some merge-related plans (and work in progress) that I'd like > to get some feedback on in order to find what order would be best to > address things in, if there are special steps I should take while > approaching some of the bigger items, and even if folks disagree with > any of the plans. > > > Currently, I would like to: > > A) Fix cases where directory rename detection does not work with > rebase/am due to how they call merge-recursive. > > Notes: Could just wait for D & E to land before fixing. > Alternatively, email RFC to list now explaining issues and how the > fix has performance implications; poll for opinions on whether to > fix before or after D. > > B) Implement a remerge-diff ability (compare a merge commit to what an > "automatic merge" would look like)[1]. > > Notes: Possibly for cherry-picks and reverts too. Depends on C & > E. > > C) Modify/extend how path-based and mode-based conflicts are > communicated to the user. > > Notes: Particularly important as a mechanism for handling > challenges[2] with implementing the remerge-diff ability. Need to > send RFC to list with ideas to get feedback. > > D) Improve merge performance. > > Notes: Includes 4-5 specific optimizations[5], some of which I > expect to be somewhat invasive and thus may make more sense to just > make part of the new merge strategy implemented in E. Biggest > optimization depends on F. > > E) Write a new merge strategy meant to replace merge-recursive. > > Notes: Suggested by Junio[3][4]. Depends on F & G. > > F) Make file collision conflict types more consistent. > > Notes: Specifically, make rename/rename(2to1) & rename/add > conflicts behave more like add/add[6][7]. Depends on part of G. > Would prefer H to be accepted first. > > G) Improve merge-related portion of testsuite. > > Notes: Intended to help test new merge strategy with more > confidence. Will include approximately a dozen edge and corner > cases where merge-recursive currently falls short. Started at [8]; > see also [9]. Most items forward-reference "Depends on () up to here; (H) seems independent, but might be a good first start. (G) [8] is queued as origin/en/merge-recursive-tests, or do you mean to expand (G) into a mini-framework of merge-testing? i.e. run the mini test framework multiple times, each using a different merge strategy, similar to submodule tests, e.g. see t/lib-submodule-update.sh and one of its users, t1013. > H) Miscellaneous code cleanups irritating me while working on other > changes[10]. > > > My current plan was to work roughly in reverse, from H to A. Some questions: > > * Does any of this look objectionable? Going in order A-H seems slightly out-of-order to me, I'd think (H) and (G) would go first; (B) sounds like an independent feature, which could go in parallel? > * Should I post RFC questions on A and C earlier? I would think so, it is easier to give feedback on code, I would think. > * Should I split D and G? (Current plan was to keep D together, but > split G into five short slightly inter-dependent topics) I would have expected to have tests (G) as a companion of (A) or (C) rather than (D), as performance improvements would keep the test suite unchanged? > * E is kind of big. Are there any specific things folks would like to see > with how that is handled? How much abstraction can be done ahead of time such that there is an interface/API where you just plug in a new merge strategy and do not need to duplicate a lot of code/tests? Stefan