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=-2.7 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RCVD_IN_SORBS_SPAM, RP_MATCHES_RCVD,T_DKIM_INVALID 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 69E6420D0C for ; Sat, 3 Jun 2017 00:36:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751202AbdFCAgF (ORCPT ); Fri, 2 Jun 2017 20:36:05 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:35114 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751061AbdFCAgE (ORCPT ); Fri, 2 Jun 2017 20:36:04 -0400 Received: by mail-pg0-f66.google.com with SMTP id f127so3274296pgc.2 for ; Fri, 02 Jun 2017 17:36:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version; bh=qFigRH8vIEFYtGHufWhv53V+nGeaupcVCHSYmHVkI8I=; b=thK261MrLjYWHNsIL0uPq7DqdJ1Gn6gVDG6waVDlYNCBl65iFaH46ppSk+6hSeFzN0 43aVaDXKwcLcjCNpvov1ax6U+vBHBc/mRw2ujqf0bUo+7Hv/kOsnWiMOxwGUe3JcYJGw tupu8lXp/pq5xBFud+Y0rTZGqy2uXr66MxQeg7btZKdi2Wwgp6KUATzh9M+RblhbhAoU h2kPf0AH+tUAtzFuvqqffwcJZjRWCPMMsSxOaTtsV1NbFsrv++Lq3dD+pPMRxb8w09oh 7DkDn6GxbPySb1xTyrJ6uqmfj9UNQW2sNbWwUCxdpNcUs3GBdu2IO3rUNbmpeQN0Ntc8 x5wA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:references:date :in-reply-to:message-id:user-agent:mime-version; bh=qFigRH8vIEFYtGHufWhv53V+nGeaupcVCHSYmHVkI8I=; b=FSfyJZkTUrRdcy2yBQACXSUXE4NeJaw9I1dm1Heo6B+eUIbRwANRk367HfmWwTORBz 3LijU+ff/ZzHoC5t+3uc6jZZSeKEQIJtbfzLOZg965owjnxVJ52veLNb7omTj/8CCBc+ f7baxIqBDgff/jZHober58VadOEPvZrHWaLszQvBghz9C5lHHExsmOgdKqaAXya5JTnu pf//aNzwmRiPays243a1Icq9vftlkQjJicDAr68UrbgSNuwbZw/g7hxYs3jat9X15Ggx xozMB91D2L/lZHvrshJzQJLy0kBgpW7/lvIOiZlr5pVwwMaMhm8PemxiMXGXx1VBq9+Q Os8g== X-Gm-Message-State: AODbwcBcGYOuVqjHXazZ/iisttKqsoY6siVgyAuIGr5o8er4nKxF/uIX F/FO4AzKFe0/gQ== X-Received: by 10.84.236.77 with SMTP id h13mr2618135pln.5.1496450164067; Fri, 02 Jun 2017 17:36:04 -0700 (PDT) Received: from localhost ([2620:0:1000:8622:49ac:b4b9:21bb:8989]) by smtp.gmail.com with ESMTPSA id 80sm41924962pfx.80.2017.06.02.17.36.03 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Fri, 02 Jun 2017 17:36:03 -0700 (PDT) From: Junio C Hamano To: Jonathan Nieder Cc: Johannes Schindelin , Stefan Beller , Phillip Wood , "git\@vger.kernel.org" , =?utf-8?B?w4Z2YXIgQXJu?= =?utf-8?B?ZmrDtnLDsA==?= Bjarmason Subject: Re: pushing for a new hash, was Re: [PATCH 2/3] rebase: Add tests for console output References: <20170531104213.16944-1-phillip.wood@talktalk.net> <20170531104213.16944-3-phillip.wood@talktalk.net> <20170602175455.GA30988@aiede.mtv.corp.google.com> Date: Sat, 03 Jun 2017 09:36:02 +0900 In-Reply-To: <20170602175455.GA30988@aiede.mtv.corp.google.com> (Jonathan Nieder's message of "Fri, 2 Jun 2017 10:54:55 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Jonathan Nieder writes: > 2. Hard-coded object ids in tests: As Stefan hinted, many tests beyond > t00* make assumptions about the exact values of object ids. That's > bad for maintainability for other reasons beyond the hash function > transition, too. > > It should be possible to suss them out by patching git's sha1 > routine to use the ones-complement of sha1 (~sha1) instead and > seeing which tests fail. One particularly nasty one is t1512-rev-parse-disambiguation that ensures that the abbreviation and disambiguation works correctly. It uses a set of objects (tags, commits, trees and blobs) whose object names all begin with number of "0"; which will of course become useless once we change the hash function. No matter what new hash function is chosen, we'd need a similar test to ensure that disambiguation works correctly, so one of the tasks for hash migration is to port (not drop) this test.