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=-2.6 required=3.0 tests=AWL,BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD shortcircuit=no autolearn=no 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 0D95E1F404 for ; Mon, 26 Feb 2018 21:30:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751791AbeBZV36 (ORCPT ); Mon, 26 Feb 2018 16:29:58 -0500 Received: from mout.gmx.net ([212.227.15.18]:60929 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751752AbeBZV3v (ORCPT ); Mon, 26 Feb 2018 16:29:51 -0500 Received: from [192.168.0.129] ([37.201.195.115]) by mail.gmx.com (mrgmx002 [212.227.17.190]) with ESMTPSA (Nemesis) id 0M9Jss-1f0pPS31Ha-00CfYK; Mon, 26 Feb 2018 22:29:44 +0100 Date: Mon, 26 Feb 2018 22:29:43 +0100 (STD) From: Johannes Schindelin X-X-Sender: virtualbox@MININT-6BKU6QN.europe.corp.microsoft.com To: git@vger.kernel.org cc: Junio C Hamano , Jacob Keller , Stefan Beller , Philip Oakley , Eric Sunshine , Phillip Wood Subject: [PATCH v5 08/12] rebase: introduce the --recreate-merges option In-Reply-To: Message-ID: <31098ae586dcd2c5b08e3f7db1a99d1ccef64ed8.1519680483.git.johannes.schindelin@gmx.de> References: User-Agent: Alpine 2.21.1 (DEB 209 2017-03-23) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Provags-ID: V03:K0:E+ESuDwAlfezINrbC8wxqJLhZQ7iG+pV3jVx3mogCVm6gzKHIpF mEd5TQ0kJp2t2TJoDehiCUqa41CUAYQEb7VvltuT/mXwhkaNpmszW/96vyrFkRDG/0Uezsn cX+xzZs91dmpWIEtILa7lhgkISKNvT2eIqqzlqu7DdtFtlvPJw74iWlXfq5L4jUmXWMSTXV 2yrTm3Ak/qZvBXg6mdIhw== X-UI-Out-Filterresults: notjunk:1;V01:K0:/up4OF1Rpak=:R3XdnZe0D8WrR3HP3F8YUX dNlZeukrRVIRFNOjMhF/t6cCSUKeh9tSm8PmiL+vY9bbUe70UXGIZJpF/M83qfx1sK1yod3AI mRtPgRwDfkOk20vQ3fCnui/nwUYUyQiR3Na/Q5d/QFVGpQp8HV3XBlcLgBsE2BRFJ77UCCqwQ L41IeL/8EhdwtsJ9L4EXl41JwYVhA1bBenFUfkl6uYTp0v8lc4hoSiVqkCDuP7HwHWkn0quBs rLzwT3HjvzwT8rtrodPa5q1Y7AgrSlrmRonep5DBnjyScsur9PO4adPVirI2fOaLtXc4/jvo2 XMb7fvKWBELqzC9RhiVJ05FaTGUd/O5c+TJms7DuFMVVmKKy7dd4EaJZ6dCM4no5R1sVAVmgw KB7wq3yknZ3KszE4t1O9SkPmLPRgUJaTcUXCZx2xYQW2EsCDsoTXkm3mk+Y+DyvZ6lGrNQvYh SpZFN7L/GZl2SQa+yoV8OU22t96N+R7qqfQGXJP5zO7rV1zUtnloRHZ9ffs/qPJ5MS3eEH4sr IL8Fn6Eyg77hdFGAKRSKDOo10ZTZV0S81XgiQWgouagx2TPTWxJ8U/+iL9qL6F+xA0MHcXB6O b6vl8emabQOeCVlDkrIJEgwrwCaWuTG6e+HRsZBkelRJ4xjoLzrjpKim6p51ZhAdfe6RHdW7x 1kfFxXKmKtwbpF0LKZLyJuG6Gw7hLrArC2yAsFF0rhXoYFdk3rlovoDfD0adCnFfDr6NNeOWx eTqu3HhVtj7cDxSaDnfC8r5b+uULiV1URmkQgLu/HTk42D5xaQB/m39jD1r1+Kum0BgrguH3i Gxfo7Cd114pIoFUrwxD1BhbuDimggmMYdarHhJz4y9gTcFdDNF/C2KpFC4J+kOycB9RI6Gz Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Once upon a time, this here developer thought: wouldn't it be nice if, say, Git for Windows' patches on top of core Git could be represented as a thicket of branches, and be rebased on top of core Git in order to maintain a cherry-pick'able set of patch series? The original attempt to answer this was: git rebase --preserve-merges. However, that experiment was never intended as an interactive option, and it only piggy-backed on git rebase --interactive because that command's implementation looked already very, very familiar: it was designed by the same person who designed --preserve-merges: yours truly. Some time later, some other developer (I am looking at you, Andreas! ;-)) decided that it would be a good idea to allow --preserve-merges to be combined with --interactive (with caveats!) and the Git maintainer (well, the interim Git maintainer during Junio's absence, that is) agreed, and that is when the glamor of the --preserve-merges design started to fall apart rather quickly and unglamorously. The reason? In --preserve-merges mode, the parents of a merge commit (or for that matter, of *any* commit) were not stated explicitly, but were *implied* by the commit name passed to the `pick` command. This made it impossible, for example, to reorder commits. Not to mention to flatten the branch topology or, deity forbid, to split topic branches into two. Alas, these shortcomings also prevented that mode (whose original purpose was to serve Git for Windows' needs, with the additional hope that it may be useful to others, too) from serving Git for Windows' needs. Five years later, when it became really untenable to have one unwieldy, big hodge-podge patch series of partly related, partly unrelated patches in Git for Windows that was rebased onto core Git's tags from time to time (earning the undeserved wrath of the developer of the ill-fated git-remote-hg series that first obsoleted Git for Windows' competing approach, only to be abandoned without maintainer later) was really untenable, the "Git garden shears" were born [*1*/*2*]: a script, piggy-backing on top of the interactive rebase, that would first determine the branch topology of the patches to be rebased, create a pseudo todo list for further editing, transform the result into a real todo list (making heavy use of the `exec` command to "implement" the missing todo list commands) and finally recreate the patch series on top of the new base commit. That was in 2013. And it took about three weeks to come up with the design and implement it as an out-of-tree script. Needless to say, the implementation needed quite a few years to stabilize, all the while the design itself proved itself sound. With this patch, the goodness of the Git garden shears comes to `git rebase -i` itself. Passing the `--recreate-merges` option will generate a todo list that can be understood readily, and where it is obvious how to reorder commits. New branches can be introduced by inserting `label` commands and calling `merge