[Debian #640669] gfsplit /foo/bar/baz doesn't work as expected

In <http://bugs.debian.org/640669>, A. N. Other writes:
> If you do
>
> $ cd
> $ gfsplit /etc/passwd
>
> gfsplit will attempt to create shares called /etc/passwd.NNN, and
> fail, assuming you're not root. This violates the principle of least
> surprise; I would expect it to create shares called passwd.NNN in the
> current directory (i.e. it should use the basename of the input file
> as the output stem, rather than the whole path), in the manner of
> split(1).

I'm not sure which is better, the current behaviour or the split(1) behaviour.