Re: [RFC/PATCHv2] git submodule split

[Lars Hjemli <hjemli@gmail.com>]

On Sat, Feb 14, 2009 at 06:17, Eric Kidd <git@randomhacks.net> wrote:
> On Fri, Feb 13, 2009 at 11:37 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> Eric Kidd <git@randomhacks.net> writes:
>>> ...
>>> If the submodule has moved around the source tree, specify one or more
>>> values for alternate_dir.  To specify the URL of the newly created
>>> repository (for use in .gitmodules), use the --url parameter.
>>
>> Unfortunately, I do not think we have designed fully (nor implemented at
>> all) behaviour to check out different points of history that has the same
>> submodule moved around in the superproject tree.
>>
>> There were several unconcluded discussions done in the past (and I admit I
>> participated in a few of them), but it may be hard to use the resulting
>> repository out of this tool.
>
> Thank you for looking at this proposal!
>
> I think that the resulting repository is usable (though it could
> certainly be better). In particular, the following commands will
> always give you a working checkout:
>
>  git checkout any-version
>  git submodule update --init
>
> The unit tests for git-submodule-split.sh actually walk through the
> entire history and run 'git submodule update --init' at each revision.
> This works correctly because git-submodule-split creates the necessary
> .gitmodules entries for each revision, and includes the
> submodule.*.url value that you specify.
>
> Unfortunately, this means that whenever the submodule moves to a new
> location in the tree, 'git submodule --init' will actually have to
> clone it again. That's not a perfect situation, but it will work for
> reasonably small submodules.

<hand-waving>
I didn't look at the patch, but if the submodule uses a single
module-name while moving around, the re-cloning problem would by
solved if the submodule git-dir was stored inside the git-dir of the
containing repository  (by using the git-file mechanism). Maybe I
should try to finally implement this...
</hand-waving>

--
larsh