Re: [PATCH] sha1-file: make pretend_object_file() not prefetch

From: Jeff King <peff@peff.net>
Date: Jul 23, 2020, 17:47 UTC
Message-ID: <20200723174747.GA3975154@coredump.intra.peff.net>
In-Reply-To: <xmqq4kq078ks.fsf@gitster.c.googlers.com>

On Tue, Jul 21, 2020 at 04:27:15PM -0700, Junio C Hamano wrote:

Show 11 quoted lines

> Jonathan Tan <jonathantanmy@google.com> writes:
> 
> > When pretend_object_file() is invoked with an object that does not exist
> > (as is the typical case), there is no need to fetch anything from the
> > promisor remote, because the caller already knows what the object is
> > supposed to contain. Therefore, suppress the fetch. (The
> > OBJECT_INFO_QUICK flag is added for the same reason.)
> 
> Yes, "pretend" is also a way to lie about the contents IIRC, so even
> if the object is available elsewhere, we should *not* fetch from the
> promisor.  Makes sense to me.

I agree this patch is fine, but I wonder if it could go even further. If we are pretending some particular contents, shouldn't we override anything that might be in the object database? I.e., could we eliminate this has_object_file() entirely?

That should be OK for the same reason that it's OK to use QUICK.

There's only one caller of this function (git-blame), which I think would be happy with such a change.

-Peff