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Subject: Re: email as a bona fide git transport
To:     Willy Tarreau <w@1wt.eu>, Greg KH <greg@kroah.com>,
        Santiago Torres Arias <santiago@nyu.edu>,
        Vegard Nossum <vegard.nossum@oracle.com>,
        workflows@vger.kernel.org, Git Mailing List <git@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, Eric Wong <e@80x24.org>
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From:   Nicolas Belouin <nicolas.belouin@gandi.net>
Message-ID: <4ea21178-0cac-e958-7c69-ad5b4a74e6b5@gandi.net>
Date:   Fri, 18 Oct 2019 08:34:17 +0200
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On 10/18/19 4:52 AM, Willy Tarreau wrote:
> On Thu, Oct 17, 2019 at 09:54:47PM -0400, Konstantin Ryabitsev wrote:
>> On Thu, Oct 17, 2019 at 06:30:29PM -0700, Greg KH wrote:
>>>> It could only possibly work if nobody ever adds their own
>>>> "Signed-Off-By" or
>>>> any other bylines. I expect this is a deal-breaker for most maintainers.
>>> Yeah it is :(
>>>
>>> But, if we could just have the signature on the code change, not the
>>> changelog text, that would help with that issue.
>> We totally should, and I even mused on how we would do that here:
>> https://public-inbox.org/git/20190910121324.GA6867@pure.paranoia.local/
>>
>> However, since git's PGP signatures are made for the content in the actual
>> commit record (tree hash, parent, author, commit message, etc), the only way
>> we could preserve them between the email and the git tree is if we never
>> modify any of that data. The SOB and other trailers would have to only be
>> applied to the merge commit, or migrate into commit notes.
> There's also the possibility to handle this a bit like we do when adding
> comments before the SOB: a PGP signature would apply to the text *before*
> it only. We could then have long chains of SOB, PGP, SOB, PGP etc.
>
> Willy

I don't think it can work that easily as the signed content is not just
the message.
It would need git to support nesting signatures and to allow amending a
commit without
touching the signature and to allow adding one to cover the new content
and to have a
way to verify every step.
Moreover you won't be able to reparent the commit as a maintainer (wich
I think is
also a deal-breaker)

Nicolas