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: AS3215 2.6.0.0/16 X-Spam-Status: No, score=-2.6 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by dcvr.yhbt.net (Postfix) with ESMTP id 8A8FF1F4D7 for ; Sat, 11 Jun 2022 08:56:37 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="GpT0z64Z"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231932AbiFKI4e (ORCPT ); Sat, 11 Jun 2022 04:56:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230158AbiFKI4d (ORCPT ); Sat, 11 Jun 2022 04:56:33 -0400 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AAF601021 for ; Sat, 11 Jun 2022 01:56:32 -0700 (PDT) Received: by mail-ed1-x534.google.com with SMTP id n28so1556713edb.9 for ; Sat, 11 Jun 2022 01:56:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PYrBL6ChgrUyJ9m30xspaVs79bC/wpr/7zgb95YnrU4=; b=GpT0z64Z0ZmHkczOAvX5eUcfcnGFi/FY5IQBK0p0KsXQ/X6dpbeNPXAfO71Elix6c5 +Ec0uxxdY93Y64D/FPCYjr9VCdci0uPSvsc3WZHgcmIdGSFXLdkeuiEo1dqc3YR/E9zc X/JFcimtFKPvqs2uGu1LqfLPJCi1lDpxxSMqSRzcD0xxX8HfzILPRMShRjOC1pwgLKhJ 7TIQe0NMoOfrNKTwvGKuCAhFpXaDX3m5KP7KE13S9qjvmegJtSQFI7+heykHvXV4k4CE KL2beJsEkmN/LHw6NDhqPhLV33arHGIqX/9otK2yw0OAuIutwtTDO4jrpo8j+7ZjWl1F 3dyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PYrBL6ChgrUyJ9m30xspaVs79bC/wpr/7zgb95YnrU4=; b=OIORg8vnyJZ1ewduzQyPyYOLyqzWkLa9OklvICwFwNIi9Z+tgc2TB4U7jls+qDeUww 667UVFvMFaeqsc3EtbEQ0GyEBoHEQGzxujzVu3lQlO8l44sQe95A7n9ACawOlSWx75B9 NYQUQFYD6zvbmLbmsiXT+x1yBlUJjZGWLs51ve4F+kESiCDn1ZJS6jEBJz7b/720flf/ KR4AFFGvKDR7Xaa7zpHyZIM7mnFaLUErtwnTbNz/auy7cZyGmdnrDhdAvVTnaMIyWhdv AjKk1FGzXyIeFZP66WBgRCkttW2HrJDMx5ihfIE4FZ8yQrysh2QHQ3S6/rD+wR63Nfpx ghIQ== X-Gm-Message-State: AOAM5334Q2oz4BgKiLb4uv/WVmCimpc/c5axycbGhaxM/mAhdyVe2a3q YU85t1cR6vG3abOK0YIMFFSO8fmOxnFjfLLifhJgyJL4 X-Google-Smtp-Source: ABdhPJxLF98IWDCeRoUKINiciqS1FtFX+KnW0S5Fq7hAXg4Ms2raSpkf+4rJ0koGj0fIFUFt3Fz/tpTRn9uYwK1WoRY= X-Received: by 2002:a05:6402:4255:b0:431:34c3:6018 with SMTP id g21-20020a056402425500b0043134c36018mr40475214edb.146.1654937791075; Sat, 11 Jun 2022 01:56:31 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Elijah Newren Date: Sat, 11 Jun 2022 01:56:19 -0700 Message-ID: Subject: Re: Bug in merge-ort (rename detection can have collisions?) To: Junio C Hamano Cc: Glen Choo , Git Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Fri, Jun 10, 2022 at 9:53 AM Junio C Hamano wrote: > > Elijah Newren writes: > > > On Tue, Jun 7, 2022 at 5:11 PM Glen Choo wrote: > >> > >> (I'm not 100% what the bug _is_, only that there is one.) > >> > >> = Report > >> > >> At $DAYJOB, there was a report that "git merge" was failing on certain > >> branches. Fortunately, the repo is publicly accessible, so I can share > >> the full reproduction recipe: > >> ... > > Thanks for the detailed report; very cool. Interestingly, if you > > reverse the direction of the merge (checkout origin/upstream-master > > and merge origin/master) then you get a different error: > > ... > > Anyway, long story short...I don't have a fix yet, but just thought > > I'd mention I saw the email and spent some hours digging in. > > Thanks for continued support for the ort strategy. From the very > beginning, I was hesitant to make our tools try to be too clever > with excessive heuristics, but at least we are not making a silent > mismerge in this case, so it is probably OK, especially with "-s > recursive" still left as an escape hatch. I'm pretty sure the bug would still trigger even if we removed all the heuristic differences that the ort strategy has relative to the recursive one; I don't think those are related to this problem at all. In fact, the more general problem area here appears to affect the recursive strategy as well. I'm glad the specific testcase reported works under recursive and gave Glen (or his user) a workaround, but that feels like luck rather than design because my minimal reproduction testcase not only triggers the same issue he saw with the ort strategy, but also triggers a previously unknown fatal bug in the recursive strategy too.