Re: Latest master failing t7401 submodule tests

Jeff King [off-list ref] writes:

quoted

 - "git submodule summary path...", defaults to HEAD which is _not_ unborn
   (we shouldn't shift).

I don't think this is a problem. We do:

  git rev-parse -q --verify --default HEAD path

and it correctly reports failure, so we never do the problematic shift.

Stepping back a bit, why do we even special case an unborn branch case in
the first place?  

    rm -fr one && git init one && cd one && git diff HEAD

would diagnose it as an error (we may want to sugarcoat "ambiguous
argument" error message, but that is a tangent).

I may be able to buy "status/diff internally calls submodule summary, and
that codepath needs to special case a submodule on an unborn branch _for
such and such reasons_" if the reasoning is sound, but even if that is the
case, shouldn't that special case be triggered explicitly by the caller of
"submodule summary" with an option?