Re: [RFC/PATCH v3 3/3] archive.c: add basic support for submodules

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

Lars Hjemli <hjemli@gmail.com> writes:

> On Fri, Jan 23, 2009 at 20:23, Junio C Hamano <gitster@pobox.com> wrote:
>> Lars Hjemli <hjemli@gmail.com> writes:
>>
>>>>> The plan is to fix these limitations by extending --submodules to allow
>>>>> certain flags/options:
>>>>> a|c|r     include any|checked out|registered submodules
>>>>> H         resolve submodule HEAD to decide which tree to include
>>
>> What do you mean by "decide"?  If HEAD exists (iow, the submodule is
>> checked out), the tree of the commit recorded in the superproject's
>> gitlink entry is included in the result?
>
> No, when H is specified the tree of the currently checked out
> submodule commit would be included.

That makes even less sense.  At that point you are mixing a tree with
random state from a work tree, and doing so only for submodules.  If you
want a work tree snapshot, it should be a work tree snapshot, and should
not be labelled as a snapshot out of a tree object of the superproject.

> I would find the H flag practical for my own usage of submodules. I
> almost never modify the content of the currently checked out submodule
> but I often check out a different HEAD than what is registered in the
> gitlink in the superproject (typically due to testing the superproject
> against different versions of the submodule). And for such a use case,
> being able to create a tarball of my currently checked out state seems
> useful to me.

That would be more like an enhanced version of "git archive" that takes
the work tree state, similar to how "git grep" operates on the work tree
today.

I agree that would be useful, but I have a moderately strong suspition
that your "H" hack that includes the work tree state for checked out
submodules into a view that is primarily about the "tree" object in the
superproject, without the same "take from the work tree" semantics for
paths in the superproject, is more harmful than being helpful to the users
in the longer term.  It might be simple to implement, but I do not think
its semantics can be explained sanely.