Re: [PATCHv2 0/6] git clone: Marry --recursive and --reference

> Stefan Beller <sbeller@google.com> writes:
>
>>  Some submodules in the referenced superproject may not be there,
>>  (they are just not initialized/cloned/checked out), which yields
>>  an error for now.
>
> Perhaps you can teach "git clone --reference" an new option
> (--reference-if-able) to do this?  Then
>
>     When `--reference` is given together with `--recursive`,
>     the reference repository is assumed to contain the submodules
>     as well and the submodules are setup as alternates of the
>     submodules in the given reference project.
>
> in which "assumed" is a horrible wording (leave the reader
> wondering: "so what happens to my data when the assumption does not
> hold") can become a lot more reasonable
>
>     When using --reference with --recursive, the --reference is used
>     to specify a repository that has a copy of the superproject.  If
>     that copy has submodules cloned for itself in its $GIT_DIR/modules,
>     they are used as --reference when cloning submodules in the
>     resulting clone.
>
> and readers expectation would match with the reality.  Their
> submodules would be cloned in a regular fashion if the central
> mirror does not have it, and would take advantage of it if there is
> already a clone.

>
> Come to think of it, do we even need --super-reference?  "git clone
> --reference --recursive" is a two step process, in that first the
> superproject is cloned while creating objects/info/alternates, and
> then submodules are cloned (via "update --init").  Can we make the
> procedure to clone a submodule always look at the reference of the
> superproject (i.e. objects/info/alternates) and try to borrow from
> the place in it that corresponds to the submodule?  That way, not
> just "git clone --reference --recursive" would take advantage of the
> existing mirrors of submodules, a user who does this:
>
>     $ git clone --reference $URL super
>     $ cd super
>     $ git submodule update --init ...
>
> would be able to take advantage of the "what the mirror the
> superproject uses already has" when cloning the submodules, no?