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=-3.1 required=3.0 tests=AWL,BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI 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 35B011F404 for ; Tue, 10 Apr 2018 12:30:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753157AbeDJMaJ (ORCPT ); Tue, 10 Apr 2018 08:30:09 -0400 Received: from mout.gmx.net ([212.227.15.18]:43085 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753035AbeDJMaG (ORCPT ); Tue, 10 Apr 2018 08:30:06 -0400 Received: from MININT-AIVCFQ2.fareast.corp.microsoft.com ([37.201.195.115]) by mail.gmx.com (mrgmx002 [212.227.17.190]) with ESMTPSA (Nemesis) id 0LaG7C-1ecXg60Nos-00m09H; Tue, 10 Apr 2018 14:30:00 +0200 Date: Tue, 10 Apr 2018 14:29:59 +0200 (DST) 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 , Igor Djordjevic , Johannes Sixt , Sergey Organov Subject: [PATCH v6 08/15] rebase: introduce the --rebase-merges option In-Reply-To: Message-ID: <43bd4bf3b179ad0bc593eb92bd031a1a88ab15b5.1523362469.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:K1:S12qgLGecthHgSRweASmvRiLwX6CjPzI5yBJIlj50oMmO9sK7Os AMAvqEjwhKsRHYnohdr03j5sCphy0TrFed+ldks7zyQPlHMWFQgbGKt3pXQtuMJuAV6IhV4 UgOCToQeZtppSywzdluIUVcfFc/QgMh4Nh0V9goNrfWk6auTKTnM8VODsoR+/D/wxviP2at dsluvvadyu17GwwU8TukA== X-UI-Out-Filterresults: notjunk:1;V01:K0:DS1LccVRCoM=:g325qwiViiTmyMecJ7+JBH xQkv/7V3kGfc0ebddVxQoFnd4oFnnm6F/fIi/tQt0lPgn5YnM2LTpbAoBG4f3kcmUSuiloacw eDGG2Je9xNZMzzWHa0KUaVKdC7po1LXfKDa+CS7gl5cFIYl6WWOIbFaspOSJqzg0l5oLYGnuW jlhuOxlv1W2WIHOsoYjfrF7XiNoEYWB64kLkBwuoLZew2AiStIfPPPcc2BGtL4CMV0WCphbnD 5rJftnK3JSM0vn9gWYafVHgzHZ80S7wJiC35Vci8urG/cBYtV8ub2Ks4NloRwUQxvPJ/JQVUW zHUjT0/Xb7lGJSryDBvehqwqDeFD9aK2pQTk/YB1BaH5frWqvPJHwlCoBtZErl3tpklJDG+pU agP9UZSGz819kjAO/TkK/138Sb6iq9EjK36m0kjNQeWpVEjpx+dvS76IvDiwYNxH+jOhfgOcv Go5de8byribCY1/8jXjRtUdMFSh6u5L50i2nVM48XL0CCBYCCqZi7EZ8DeOV5xFpRYMLOwwpA HbPBarRtci3FcMpHVAA//bRLe7TVJljbcI8hhX4NFoKM4PbdopKgmPMtUv7EnCVnJkf1gk7Zg lMeUkn6yTtKZAmszeAgRM1m0Lvun+63HLSdBgB/OI0soY+ml0xMieqZOIvQOD62CkkpVaxeRj atv7G7KBTYcI4+K0SyT+L7tU55TK9V8eodIrBtmyRic0ae6FAAG9IiQSNqPH/Tnymkns+W/C5 ecLVm5pWPIQhCNgDgxUwKQKvJvnnSqIRlUf4EvdJx1hJv0jm04THhLXwSqb5oASgzNuFWrln+ 7ykNnPFxbH6cpTSmPswJ175qqwzLZkKem79XRb38vTdAWwFLYE= 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 `--rebase-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