Re: [Question] Is extensions.partialClone defunct?

From: Christian Couder <christian.couder@gmail.com>
To: Jonathan Nieder <jrnieder@gmail.com>
Cc: Jonathan Tan <jonathantanmy@google.com>,
	Derrick Stolee <stolee@gmail.com>, git <git@vger.kernel.org>,
	Taylor Blau <me@ttaylorr.com>
Subject: Re: [Question] Is extensions.partialClone defunct?
Date: Sat, 14 Mar 2020 07:43:55 +0100	[thread overview]
Message-ID: <CAP8UFD1ouu1EkJjGYuzJahZNX+QW-XyEPD-2Vfp8jMYNuVYkAA@mail.gmail.com> (raw)
In-Reply-To: <20200312230931.GF120942@google.com>

Hi,

On Fri, Mar 13, 2020 at 12:09 AM Jonathan Nieder <jrnieder@gmail.com> wrote:
>
> Christian Couder wrote:
> >> Jonathan Tan wrote:
>
> >>> Hmm...besides giving the name of the promisor remote, the
> >>> extensions.partialClone setting is there to prevent old versions of Git
> >>> (that do not know this extension) from manipulating the repo.
> >
> > That could be true of "remote.<name>.promisor = true".
>
> To be clear, Jonathan is referring to a specific feature of the
> extensions.* settings.  See
> Documentation/technical/repository-version.txt for details:
>
>   2. If a version-1 repository specifies any `extensions.*` keys that
>      the running git has not implemented, the operation MUST NOT
>      proceed. Similarly, if the value of any known key is not understood
>      by the implementation, the operation MUST NOT proceed.
>
> No other config key has that property.

Yeah, right. I was very tired and it was late when I replied, so I was confused.

> > On Thu, Mar 12, 2020 at 6:51 PM Jonathan Nieder <jrnieder@gmail.com> wrote:
>
> >> Christian, what would your prefered way be to fix this?  Should
> >> extensions.partialclone specify a particular "default" promisor
> >> remote, or should we use a new repository extension for multiple
> >> promisors?
> [...]
> > So I'd rather obsolete "extensions.partialClone = <remote>" and to
> > find other ways.
>
> I *think* that means "new repository extension".

Yeah.

> That suggests something like
>
>         [extensions]
>                 multiplePromisors = true

Yeah, I think I suggested "[extensions]\npromisorremotes=<bool>" but
"multiplePromisors" is probably better.

> >                                                              or maybe
> > we could have another extension alltogether like
> > "[extensions]\npromisorremotes=<bool>" and over time obsolete
> > "extensions.partialClone" altogether. I prefer the later.
>
> I think we're going to have to continue to support
> extensions.partialClone=<remote> for a long time anyway (breaking the
> ability to work with existing repositories is expensive), so I'm
> reasonably comfortable with multiplePromisors being a separate
> extension.  Some faraway day, we can introduce
> "repositoryFormatVersion = 2" that mandates support for these
> extensions by default, allowing us to clean up and simplify.

Yeah, I agree.

> I can start writing a proposed patch to send this evening or tomorrow.

That would be very much appreciated! Thanks!

> This behavior has been around for a few releases so it would want to
> cook until the 2.27 cycle.

Yeah, and partial clone is experimental, so I think it's ok.