Re: [Question] Is extensions.partialClone defunct?

From: Jeff King <peff@peff.net>
Date: Mar 12, 2020, 21:30 UTC
Message-ID: <20200312213044.GC872402@coredump.intra.peff.net>
In-Reply-To: <xmqqsgide0i3.fsf@gitster.c.googlers.com>

On Thu, Mar 12, 2020 at 02:17:40PM -0700, Junio C Hamano wrote:

Show 19 quoted lines

> Taylor Blau <me@ttaylorr.com> writes:
> 
> > On Thu, Mar 12, 2020 at 10:51:51AM -0700, Jonathan Nieder wrote:
> >> Jonathan Tan wrote:
> >> > Derrick Stolee wrote:
> >>
> >> >> but it appears that we rely on the "remote.<name>.promisor = true"
> >> >> setting instead of this extension.
> >> >
> >> > 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.
> >
> > Manipulating it how?
> 
> Presumably if the version of Git does not assume that sometimes
> missing objects are OK, its "fsck" and "repack" would become very
> upset when a repository lacks very many objects because the version
> of Git that created it assumes they can be lazily fetched, no?

Yes (or even just "git log", which will barf when it hits a needed object). Unlike some other extensions, I don't think that case would be _dangerous_ (i.e., for any case where it matters the old version is likely to abort, thinking it's seeing corruption, rather than writing out a subtly wrong result).

But it is certainly more pleasant for the user to see "we don't support the partialClone extension" than a spew of "missing object" messages.

-Peff