From: Elijah Newren <newren@gmail.com>
Date: Thu, 19 Feb 2026 20:53:29 GMT
Subject: Re: [PATCH 4/5] merge-ort: prevent the_repository from coming back
Message-ID: <CABPp-BG94fTEhQbUy==OYiGrbQH+Tqt+GPiP6TynUCNPMP2y6g@mail.gmail.com>
In-Reply-To: <xmqq8qco4gsv.fsf@gitster.g>

On Thu, Feb 19, 2026 at 12:30 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Elijah Newren <newren@gmail.com> writes:
>
> > Yeah, also full disclosure: I do not know why
> > prefetch_for_content_merges() needs to use the_repository.  When I
> > introduced it back in 2bff554b23e8 (merge-ort: add prefetching for
> > content merges, 2021-06-22), I was just looking at diffcore_std() and
> > trying to mimic how it did the prefetch.  I don't actually understand
> > why the comparison against the_repository is there for either of these
> > functions.  Maybe someone else knows and could shed some light?  (cc:
> > Jonathan Tan for the diffcore_std() case I was copying from...)
>
> I did a bit of digging for you ;-)

Thanks!

> The comparison with the_repository is from 7fbbcb21 (diff: batch
> fetching of missing blobs, 2019-04-05), whose original version did
> not have it, but was later amended with
>
>   https://lore.kernel.org/git/20190405170934.20441-1-jonathantanmy@google.com/

Ah, the explanation in that email doesn't exist inside the commit
history, since the diff was squashed in and the relevant part of the
explanation wasn't added to the commit message.  I should have thought
to check the mail archives too.  Anyway, the important bit is:

> Also, prefetch only if the repository being diffed
> is the_repository (because we do not support lazy fetching for any other
> repository anyway).

This comment came from mid-2019.  I then copied the logic from
diffcore_std() in 2020 (though didn't get the relevant patch upstream
until 2021), and as of 2021 we have ef830cc43412 (promisor-remote:
teach lazy-fetch in any repo, 2021-06-17), which means that this check
has been obsoleted by events.  And it looks like the check in
diffcore_std() was left in place as an oversight as well.

So, we don't need that check anymore.  I'll add a commit that simply
removes these checks from both merge-ort.c and diff.c and reduces two
more uses of the_repository.