> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Sun, 02 Oct 2016 17:59:34 +0000
>
> compare-buffer-substring allows all its arguments to be nil, but the docstring doesn't say that. Attached is a
> patch that amends the docstring.

Thanks, this is fine, and should go to the emacs-25 branch.