Re: [PATCH v2 1/2] diff: enable and test the sparse index

> > But isn't the top-level directory always part of the cone? If so, I
> > think that what this (and the below test) is demonstrating is that we
> > can show changes inside of the cone without expanding the sparse-index.
> >
> > Having that test makes absolute sense to me. But I think it might also
> > make sense to have a test that creates some directory structure outside
> > of the cone, modifies it, and then ensures that both (a) those changes
> > aren't visible to `git diff` when the sparse-checkout is active and (b)
> > that running `git diff` doesn't cause the sparse-index to be expanded.
> >
> README.md is actually within the sparse checkout cone - all files at root
> are included by default. So your understanding is correct - we are ensuring
> that making a change to a file in the cone and running both diff and diff
> --staged once the file is in the index doesn't expand the sparse index.
>
> I like your idea of verifying that running diff against files outside the
> sparse checkout cone won't expand the index. I've updated the diff tests in
> v3 (which I will send out shortly) to do so.