Re: [BUG] allowtipsha1inwant serves unreachable blobs if you know its hash

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 23, 2017, 23:59 UTC
Message-ID: <xmqqpoi85ui3.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <xmqqtw7k5uxj.fsf@gitster.mtv.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 17 quoted lines

> Jonathan Tan <jonathantanmy@google.com> writes:
>
>> Adding "--objects" works, and all existing tests pass, except for the
>> potential performance issue and the side effect that even fetching a
>> reachable blob no longer works. This is due to a possible bug where a
>> call like "git rev-list --objects $tree ^master" (where $tree is the
>> tree object corresponding to master) prints out objects ...
>
> The "reachable from this, excluding what is reachable from that"
> notation was originally designed to work only on commits, and I
> wouldn't be surprised if "$tree ^master" did not work as you expect
> in the current implementation.
>
> I agree that ideally it shouldn't show anything, but I suspect that
> it would make it very expensive if done naively---we'd end up having
> to call mark_tree_uninteresting() for all uninteresting commits, not
> just for the commits at the edge of the DAG as we do right now.

BTW, by "it would be expensive" I didn't mean "hence it shouldn't be done." Even though I do not know by how much expensive it would become, I think this approach is a lot better way going forward than punting and say "no, you cannot specify anything lower than commit."

Thanks for looking into this.