Re: [PATCH 2/2] packfile: recover when a multi-pack-index names a removed pack

[Patrick Steinhardt <ps@pks.im>]

On Mon, Aug 24, 2026 at 12:48:22AM -0400, Jeff King wrote:
> So between the two cases, it sounds like things (or at least the
> low-level lookups) are working as designed, and there is no bug. Or am I
> misunderstanding something?

I agree that QUICK is working as designed, and that callers that pass it
without being able to accommodate for false negatives are buggy. But the
patch sent by Elijah still fixes an actual bug where we may not find an
object that is contained in two MIDXd packs where the preferred pack for
a respective object vanishes concurrently. Filling the packfile entry
via the MIDX will fail because the pack vanished, and the lookup via the
non-preferred pack will fail, too, because we skip over any packs that
are covered by the MIDX when doing the non-MIDX lookup. Consequently, we
won't find the object at all.

That case is broken no matter whether we pass QUICK or not.

Patrick