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=-4.4 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,NICE_REPLY_A, 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 A8DCC1F66E for ; Fri, 14 Aug 2020 02:33:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbgHNCdW (ORCPT ); Thu, 13 Aug 2020 22:33:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726570AbgHNCdW (ORCPT ); Thu, 13 Aug 2020 22:33:22 -0400 Received: from mail-qt1-x843.google.com (mail-qt1-x843.google.com [IPv6:2607:f8b0:4864:20::843]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F1DAC061757 for ; Thu, 13 Aug 2020 19:33:22 -0700 (PDT) Received: by mail-qt1-x843.google.com with SMTP id v22so6014819qtq.8 for ; Thu, 13 Aug 2020 19:33:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=+vk6btUCd6tSTvgi30RRTdLT9Slxv3c6r+r3PCUgaJY=; b=Vcm/ekvWr6KJU5i41KAS0d5bu6jJRmav9U4HZJp0EXY9mUVSWqHxf6KbCD7v6TcfhA RTK+XCTos0k6C85XTVvPIlIwF7IDMHS5lDwJmmf4dIjvttT4PaPDRKg02nFfbIVAJTID aqCS1pZBU4o+HffJMHyyFFyaa9qvgH8+qLPfUCxeo40XT/SE6zM0ZmZuEFE5oCdSCTET SDNjZAE/NWboPitoJqrCqAPIsh/ezCCt5bDyFrG0i4aAvTdP3JdabBGCPqBn4pxaU7tN H89N/H5uGqIiHRo5G6uxlQNyDzaWm2P4jMM13yen9XEk+DpY1j1rGXQGzvNBgZuG94Qx yizQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=+vk6btUCd6tSTvgi30RRTdLT9Slxv3c6r+r3PCUgaJY=; b=i5JIqEJaMk7sIrrB/V0y04phbrzxLV0Sqvv5clE+4fKw0vKNz1kWBHyhGML74Envtv ELnOUhy18ydAkGGfPD//CaSSPKIJibhKN1uywCW1BhSTiZMbsvCaFyihRxg6OG3BZ96u MPtZt7soWrUgnc9RxItzsKjkJ5PiinhwH1kMOpF7WHyLweSX7kexZtzz/Iu1m1w1mO6v Qnm1Ad52+kzw8Tqgh5Q6LUEIjq/6wGo8oZHad+X3DjOj4ZHcJKDI37BupxOdRzsNR3/8 LzrMfP0dcLg7d4Tl0/9vsaNryiBzvLVxo662wqz5KbGUfA8/1W1e0fal1MaoJeYhZseD Y75A== X-Gm-Message-State: AOAM5331RaVBBznUMd2I4Qn8O5QrL4x/5RfxXigIUiNZxNr3djDk2IqO tUSQVYdDPgtaWUyJSGOa83o= X-Google-Smtp-Source: ABdhPJwKZVaSdU+Iu+OZTKAlktrKG96yCFAH9zYzy+8m77azN14lLDJOZ7CDReGtss21tW/HwVmBeA== X-Received: by 2002:ac8:23ad:: with SMTP id q42mr269578qtq.9.1597372401447; Thu, 13 Aug 2020 19:33:21 -0700 (PDT) Received: from ?IPv6:2600:1700:e72:80a0:7dfc:cd76:faf5:aaad? ([2600:1700:e72:80a0:7dfc:cd76:faf5:aaad]) by smtp.gmail.com with ESMTPSA id s30sm8922490qtc.87.2020.08.13.19.33.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 13 Aug 2020 19:33:20 -0700 (PDT) Subject: Re: [PATCH 0/2] Documentation updates for SHA-256 To: "brian m. carlson" , git@vger.kernel.org Cc: =?UTF-8?Q?Martin_=c3=85gren?= References: <20200813224901.2652387-1-sandals@crustytoothpaste.net> From: Derrick Stolee Message-ID: Date: Thu, 13 Aug 2020 22:33:20 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:80.0) Gecko/20100101 Thunderbird/80.0 MIME-Version: 1.0 In-Reply-To: <20200813224901.2652387-1-sandals@crustytoothpaste.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 8/13/2020 6:48 PM, brian m. carlson wrote: > As was pointed out recently, some of our documentation doesn't properly > reflect the new support for SHA-256. Just to bring up some subtlety in Martin's message [1], there is some valid concern that the existing file formats are not correctly versioned "in a vacuum." When they are in a repository that has SHA-256 set as its hash algorithm, Git interprets these file formats correctly, but if a *.pack file (and its *.idx) happened to be copied into the pack directory of a Git repository still in SHA-1 mode, then Git would get confused and probably fail miserably. Is that really a concern? Maybe, but also Git will never move data like that. The main thing is to focus on compatibility of the .git directory as a whole (and the protocol, as we move into inter-operability mode). [1] https://lore.kernel.org/git/CAN0heSptiJL9d86ZeNPMUaZeTA68juwTyf3K-uWR=K-vt=1Hrg@mail.gmail.com/ > This series updates the pack and > index documentation to reflect that these formats can handle SHA-256, > and updates the transition plan to reflect what we've implemented and > what the next steps are. These patches are good to help clarify these formats in the new world. Thanks, -Stolee