First of all, patches 1 and 2 look good since they are the same as in
v1 and I have reviewed them. Moving on...

Glen Choo [off-list ref] writes:

The changed function signatures follow repo_submodule_init()'s argument
order, i.e. "path" then "treeish_name". Where needed, reorder the
arguments of functions that already take "path" and "treeish_name" to be
consistent with this convention.

This paragraph made me nervous, but looking at the diff, you didn't
actually reorder any arguments. Probably best to delete this paragraph.

The fact that the additional functionality is not used also means that
we can't tell for sure if all relevant functions are indeed changed, but
perhaps we can determine this in a later patch.