Re: Strangeness with git-add and nested repositories

Junio C Hamano [off-list ref] writes:

My undertanding of what _should_ happen in the world order as
currently defined (not necessarily implemented) is:

 * "git add -- A B" must work the same way as "git add -- B A" and
   "git add -- A; git add -- B"

 * "git add -- path/to/subdir/file", when any of path/, path/to/,
   path/to/subdir/ is a Git repository that is different from the
   current Git repository, must fail.

IOW, if 'path' is a repository (whether it is known as a submodule
to the repository whose working tree contains it, or it is an
untracked directory from the containing repository's point of view),
the index of the containing repository cannot get path/$anything in
it.  If you managed to do so, you found a bug [*1*].

path/.git/index can of course have "to/subdir/file" in it, and from
that point of view, "git -C path/to/subdir add file" may one day
become an improved world order.  It is just we haven't discussed
that possibility or reached concensus that it is a good idea.

A cursory bisection suggests that this used to work up to at least
v2.7.4; this must be a recent regression.