Linus Torvalds [off-list ref] writes:
I also think that test is historical, from before Junio cleaned up how
"git commit" worked - it _used_ to be that "git commit" would work in the
current index, but these days it generates a new index to commit when you
do "-o", so there's really no _technical_ reason to refuse the partial
commit any more as far as I can see.
So I don't know. I don't think you were being dumb, I think git could have
been friendlier to you.
I have to go back to the list archive, but if I recall correctly
the refusal was added to be friendlier -- by being safer -- and
was not there in the earlier round of -o/-i proposal.