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-Status: No, score=-3.6 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_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 454601F9FE for ; Mon, 1 Mar 2021 20:09:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242644AbhCAUHY (ORCPT ); Mon, 1 Mar 2021 15:07:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242486AbhCAUCt (ORCPT ); Mon, 1 Mar 2021 15:02:49 -0500 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F247BC061756 for ; Mon, 1 Mar 2021 12:02:08 -0800 (PST) Received: by mail-ed1-x532.google.com with SMTP id b7so8887010edz.8 for ; Mon, 01 Mar 2021 12:02:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:references:user-agent:in-reply-to:date :message-id:mime-version:content-transfer-encoding; bh=XQTvYnhSOGvAAj+6LmANBOpZ67XN0+2LzZzwc/a/PrU=; b=Lv03pMYuEVM1Y2BcmoZ9FD/IO+cmQRQvv0d5c4DMbtJq58SEYvvAffoP1xuGjq9Tsn 5XFqBvlytubvFlo9eX3xJZ6bfRRRU2mSj+Kk7V0eeMv0AM4lkO4PdqTywwi3NEvYyg6P isk2Q1GgXjisvo6wb7Q/SiRXTmcgBh+x05E8QoSvRFJ1bg8qc1PzS0uV9wPgsfiwGm8I ezPqdIYbP//mY8bryQkMS4Cr75ag5eFbKL2Kl8/gjkAhxfProG3ec98KIGlxnnNlwUgT OwCH7oxpJ7WcRe4xiYdri6sFtnps45znm9lVD7LVxKbtdIbCLYcX+XWTUfudUjtUh9qW +z9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:references:user-agent :in-reply-to:date:message-id:mime-version:content-transfer-encoding; bh=XQTvYnhSOGvAAj+6LmANBOpZ67XN0+2LzZzwc/a/PrU=; b=CvdNw2THBRaM4XuptY8V6M/fL1Qrwl8vkioBC+EyAf/UeeRq2neXG/XG1dQUUwZxqj Furas81MeA0F3nPNvEOtQri95+WOjNTD57TEzKW9r1BmYHNbd3b4Dpd6WdYkdhhAcRJW QI3sijKvNwFzxZsfje+li/EhpZtTqusZyQKYN3fGTO0PupkpHjgz5tSqZICHUfnWHMPD QJua2pYv1CUdJ6dxV+Nx5KvNq7IR+HE7NX/8UTlIK3cS+pL/pT+pHbyQAKdu8OZtlMSw DStfc1Jr08LK3uiq9YRHpeed7VUw6gGhEk1xpA72/6nWax+PtliFFqJukK2swvPYTkF6 v7tQ== X-Gm-Message-State: AOAM532LA35BenLPmy9PnxrRRYQZVatSWXJL9djAm/5iKvH1+IcpRz8t qTH0RRHrv5lL9sor1YMFPXPNo4fbuCw= X-Google-Smtp-Source: ABdhPJzxffFo+FyXTzyb/9K10eLQkCUwss6IzoaOspt1sKZqzBhRAyRz7jhycDhVibvSuDoZJ6IpXw== X-Received: by 2002:a50:aac8:: with SMTP id r8mr17606462edc.9.1614628927669; Mon, 01 Mar 2021 12:02:07 -0800 (PST) Received: from evledraar (j57224.upc-j.chello.nl. [24.132.57.224]) by smtp.gmail.com with ESMTPSA id yk8sm10644809ejb.123.2021.03.01.12.02.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Mar 2021 12:02:07 -0800 (PST) From: =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason To: anatoly techtonik Cc: Elijah Newren , Git Mailing List Subject: Re: Round-tripping fast-export/import changes commit hashes References: <87mtvolbuj.fsf@evledraar.gmail.com> User-agent: Debian GNU/Linux bullseye/sid; Emacs 27.1; mu4e 1.4.15 In-reply-to: Date: Mon, 01 Mar 2021 21:02:06 +0100 Message-ID: <87im6ak5hd.fsf@evledraar.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Mar 01 2021, anatoly techtonik wrote: > On Sun, Feb 28, 2021 at 1:34 PM =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason > wrote: >> >> I think Elijah means that in the general case people are using fast >> export/import to export/import between different systems or in >> combination with a utility like git-filter-repo. >> >> In those cases users are also changing the content of the repository, so >> the hashes will change, invalidating signatures. >> >> But there's also cases where e.g. you don't modify the history, or only >> part of it, and could then preserve these headers. I think there's no >> inherent reason not to do so, just that nobody's cared enough to submit >> patches etc. > > Is fast-export/import the only way to filter information in `git`? Maybe = there > is a slow json-export/import tool that gives a complete representation of= all > events in a repository? Or API that can be used to serialize and import t= hat > stream? Aside from other things mentioned & any issues in fast export/import in this thread, if you want round-trip correctness you're not going to want JSON-anything. It's not capable of representing arbitrary binary data. But in any case, it's not the fast-export format that's the issue, but how the tools in git.git are munging/rewriting/omitting the repository data in question...