Re: Multiple fetches when unshallowing a shallow clone

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 4, 2015, 22:45 UTC
Message-ID: <xmqqh9jxrfy5.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20151204215158.GA27987@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 10 quoted lines

>> But why would fetching a tag (or set of tags) merit a depth of zero?
>> Doesn't depth 1 mean "give me the the objects, and none of their
>> descendants"?  Why use 0?
>
> That comes from this line:
>
>   transport_set_option(transport, TRANS_OPT_DEPTH, "0");
>
> That line blame back to b888d61 (Make fetch a builtin, 2007-09-10),
> which isn't incredibly helpful.

Hmm, "0" means "no depth limitations", which is exactly what we want in this "unshallow" case, I would think. The behaviour observed is just like a regular fetch that auto-follows tags, where it has to make a second fetch if the primary fetch fails to include everything that is needed for propagating the tag for whatever reason.

Having said that, IIRC, these days a depth limited clone is created implicitly with --single-branch option, and I am not sure what the right behaviour for the auto-following of tags in such a repository.

Show 15 quoted lines

> I think that comes from the original git-fetch.sh, which had:
>
>   ?*)
>           # do not deepen a shallow tree when following tags
>           shallow_depth=
>
> Which makes sense. I think the code at that point is not aware that we
> just "unshallowed" and can therefore drop the depth parameter
> altogether. But I admit I am not all that familiar with the shallow
> code.
>
> +cc Duy, who can probably say something way more intelligent about this
> off the top of his head. :)
>
> -Peff