Re: [PATCH v2 0/2] Update sha1dc from upstream & optionally make it a submodule

Ævar Arnfjörð Bjarmason [off-list ref] writes:

But from what you're saying here that seems like a non-issue, i.e. in
such a scenario we'd just mirror the original repo[1], change the URL
in git.git to that, and then anyone could easily use older history
since it would be pointing to the new mirror.

Those who cloned before such a switch will still have the URL they
chose when they cloned and did "submodule init" on it, I think, so
they need to explicitly choose to switch to the new URL.  So I would
not exactly say "seems like a non-issue"; it certainly is an easy
thing to work around.