Ævar Arnfjörð Bjarmason [off-list ref] writes:

These are preparatory changes to make "git submodule--helper"'s
behavior align with that of "git submodule". The next step after this
is to get rid of git-submodule.sh entirely, and make "git submodule" a
built-in.

The last two patches here are post-cleanup of related submodule code
that isn't strictly necessary, but good to do. Similarly this starts
with the removal of some dead code in the area.

The goal is to make these changes as small as possible, and as
obviously correct as possible. This will help to make the meaty
changes that follow easier to review.

Thanks for taking this up! I have some lingering confusion over the
behavior described in 02/12's commit message, but I am quite convinced
that 02/12 is good - the check that it removes is not needed for
correctness and it doesn't make much sense as safeguard for developers
[1].

Nearly everything else is very obviously correct, and I've
double-checked most of the assertions in the commit messages as well. So
I'm happy to give this my reviewed-by.

  Reviewed-by: Glen Choo [off-list ref]

[1] https://lore.kernel.org/git/kl6ltu8ci7r5.fsf@chooglen-macbookpro.roam.corp.google.com (local)