Re: [PATCH] fetch: when deepening, check connectivity fully

[Junio C Hamano <gitster@pobox.com>]

Jonathan Tan <jonathantanmy@google.com> writes:

>> Hmph, remind me how old and/or new shallow cut-off points affect
>> this traversal?  In order to verify that everything above the new
>> cut-off points, opt->shallow_file should be pointing at the new
>> cut-off points, then we do the full sweep (without --not --all) to
>> ensure we won't find missing or broken objects but still stop at the
>> new cut-off points, and then only after check_connected() passes,
>> update the shallow file to make new shallow cut-off points active
>> (and if the traversal fails, then we do nto install the new shallow
>> cut-off points)?
>
> That is the way it should work, but after thinking about it once more, I
> realize that it isn't.
>
> opt->shallow_file is not set to anything. And fetch-pack updates the
> shallow file by itself (at least, that is my understanding of
> update_shallow() in fetch-pack.c) before fetch calls check_connected(),
> meaning that if check_connected() fails, there is still no rollback of
> the shallow file.

Ouch.  We need to fix that; otherwise, a broken server will keep
giving you a corrupt repository even with this fix, no?