From: Junio C Hamano <gitster@pobox•com>
To: "brian m. carlson" <sandals@crustytoothpaste•net>
Cc: git@vger•kernel.org, Patrick Steinhardt <ps@pks•im>
Subject: Re: [PATCH 10/10] Enable SHA-256 by default in breaking changes mode
Date: Fri, 20 Jun 2025 13:42:52 -0700 [thread overview]
Message-ID: <xmqqa5622lgz.fsf@gitster.g> (raw)
In-Reply-To: <aFWzTv5-AjUvXWsg@fruit.crustytoothpaste.net> (brian m. carlson's message of "Fri, 20 Jun 2025 19:15:26 +0000")
"brian m. carlson" <sandals@crustytoothpaste•net> writes:
> On 2025-06-20 at 15:03:23, Junio C Hamano wrote:
>> Another thing that I suspect nobody wrote tests for, but we must be
>> absolutely certain, is that the post-3.0 Git can still interoperate
>> well with historical SHA-1 repositories (I am not talking about
>> "fetch from SHA-1 into SHA-256", but "the binary does not lose
>> ability to work in SHA-1 repositories or fetch/push between SHA-1
>> repositories, only because the default is set to SHA-256"), even in
>> old repositories people have been using for ages without the
>> core.repositoryformatversion defined.
>
> Yes, I have definitely tested that here before sending it out.
Is there a single t/tXXXX-*.sh test that is dedicated to that
interoperability, or is it spread across commands (like,
t????-clone-*.sh has a test that explicitly prepares an SHA-1 and an
SHA-256 repositories and then tries to clone them with the current
binary to make sure the result look reasonable, and t????-push-*.sh
has a test to push between a pair of SHA-1 repositories, and a pair
of SHA-256 repositories, with the current binary)?
> When Git
> 3.0 comes out, we can switch our GIT_TEST_DEFAULT_HASH test from sha256
> to sha1 to continue to verify that those work. As I learned when
> writing the SHA-256 functionality and as I'm experiencing today writing
> the interop code, if clones, fetches, and pushes do not work properly,
> the testsuite is completely broken with at the very least fifty-some-odd
> tests failing, so I feel confident that functionality will continue to
> work for SHA-1 as long as we do run an appropriate test job.
OK.
> Also, when we initialize a SHA-1 repository with the files ref backend,
> we still use repository format version 0 without any extensions, so the
> cases that cover older-style configs will still be adequately tested. We
> also have some tests that even test that things work properly without a
> config file, which caught a bug in this series (that I fixed before
> sending it out).
Very nice.
Thanks.
next prev parent reply other threads:[~2025-06-20 20:42 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-20 1:19 [PATCH 00/10] Add SHA-256 by default as a breaking change brian m. carlson
2025-06-20 1:19 ` [PATCH 01/10] hash: add a constant for the default hash algorithm brian m. carlson
2025-06-20 1:19 ` [PATCH 02/10] hash: add a constant for the original " brian m. carlson
2025-06-20 1:56 ` Junio C Hamano
2025-06-20 20:43 ` brian m. carlson
2025-07-01 11:35 ` Patrick Steinhardt
2025-06-20 1:19 ` [PATCH 03/10] builtin: use default hash when outside a repository brian m. carlson
2025-06-20 14:19 ` Junio C Hamano
2025-07-01 11:35 ` Patrick Steinhardt
2025-07-01 21:14 ` brian m. carlson
2025-07-02 15:08 ` Patrick Steinhardt
2025-06-20 1:19 ` [PATCH 04/10] Use original hash for legacy formats brian m. carlson
2025-06-20 14:26 ` Junio C Hamano
2025-06-20 20:51 ` brian m. carlson
2025-06-20 21:14 ` Junio C Hamano
2025-07-01 11:35 ` Patrick Steinhardt
2025-06-20 1:19 ` [PATCH 05/10] setup: use the default algorithm to initialize repo format brian m. carlson
2025-06-20 14:55 ` Junio C Hamano
2025-06-20 20:28 ` brian m. carlson
2025-06-20 21:05 ` Junio C Hamano
2025-06-20 1:19 ` [PATCH 06/10] t: default to compile-time default hash if not set brian m. carlson
2025-06-20 1:19 ` [PATCH 07/10] t1007: choose the built-in hash outside of a repo brian m. carlson
2025-06-20 1:19 ` [PATCH 08/10] t4042: " brian m. carlson
2025-06-20 1:19 ` [PATCH 09/10] t5300: " brian m. carlson
2025-06-20 1:19 ` [PATCH 10/10] Enable SHA-256 by default in breaking changes mode brian m. carlson
2025-06-20 14:58 ` Junio C Hamano
2025-06-20 19:18 ` brian m. carlson
2025-06-20 15:03 ` Junio C Hamano
2025-06-20 19:15 ` brian m. carlson
2025-06-20 20:42 ` Junio C Hamano [this message]
2025-06-20 21:06 ` brian m. carlson
2025-07-01 11:35 ` Patrick Steinhardt
2025-07-01 21:22 ` [PATCH v2 00/11] Add SHA-256 by default as a breaking change brian m. carlson
2025-07-01 21:22 ` [PATCH v2 01/11] hash: add a constant for the default hash algorithm brian m. carlson
2025-07-01 21:22 ` [PATCH v2 02/11] hash: add a constant for the legacy " brian m. carlson
2025-07-01 21:22 ` [PATCH v2 03/11] builtin: use default hash when outside a repository brian m. carlson
2025-07-01 21:22 ` [PATCH v2 04/11] Use legacy hash for legacy formats brian m. carlson
2025-07-01 21:22 ` [PATCH v2 05/11] setup: use the default algorithm to initialize repo format brian m. carlson
2025-07-01 21:22 ` [PATCH v2 06/11] t: default to compile-time default hash if not set brian m. carlson
2025-07-01 21:22 ` [PATCH v2 07/11] t1007: choose the built-in hash outside of a repo brian m. carlson
2025-07-01 21:22 ` [PATCH v2 08/11] t4042: " brian m. carlson
2025-07-01 21:22 ` [PATCH v2 09/11] t5300: " brian m. carlson
2025-07-01 21:22 ` [PATCH v2 10/11] help: add a build option for default hash brian m. carlson
2025-07-01 21:22 ` [PATCH v2 11/11] Enable SHA-256 by default in breaking changes mode brian m. carlson
2025-07-01 22:10 ` [PATCH v2 00/11] Add SHA-256 by default as a breaking change Junio C Hamano
2025-07-02 14:46 ` Patrick Steinhardt
2025-07-02 15:01 ` Kristoffer Haugsbakk
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