On Wed, Apr 14, 2021 at 08:51:02PM -0700, Junio C Hamano wrote: > Jonathan Tan <jonathantanmy@xxxxxxxxxx> writes: > > >> When `-A` and `-d` are used together, besides packing all objects (-A) > >> and removing redundant packs (-d), it also unpack all unreachable > >> objects and deletes them by calling `git pruned-packed`. > > > > I still think of these objects as not unreachable, even though I know > > that pack-objects calls them that (the argument is called > > --unpack-unreachable). So I would say "it also loosens all objects that > > were previously packed but did not go into the new pack", but perhaps > > this is OK too. > > Hmph, that is puzzling. I understand that the operation about > > (1) finding all the objects that are still reachable and send them > into a newly created pack, and > > (2) among the objects that were previously in the packs, eject > those that weren't made into the new pack with the previous > point. > > Where did I get it wrong? If all the reachable ones are dealt with > with the first point, what is leftover is not reachable, no? Right. I think your understanding is correct, and the commit message is a bit confused. Normally after we eject loose objects, they'd stay there (a follow-up git-gc may run git-prune and delete them, though if they were recent enough not to just drop completely during the repack, then git-prune would likewise leave them be). Talking about prune-packed here is misleading, because it usually has nothing to do with these objects. What makes the partial-clone situation under discussion interesting is that the objects _are_ reachable. They are excluded from the new pack because we put them in a separate promisor pack. But we erroneously turn them loose, rather than realizing that they were excluded for a different reason. So the fundamental bug is that we turn them loose at all. What makes the bug trickier to see is that when we run prune-packed afterwards, we then clean up the evidence of the bug (so it looks more like a performance problem than a correctness one). -Peff
