bug#13447: ln "" foo gives misleading error message

[Bob Proulx]

Jim Meyering wrote:
> Pádraig Brady wrote:
> > Interestingly I notice that solaris for example allows a NULL old_path.
> 
> That Solaris behavior is contrary to POSIX 2008
> http://pubs.opengroup.org/onlinepubs/9699919799/functions/symlink.html

Where does it say this?  I read it through in detail but I didn't see
that it required a diagnostic to be emitted in the case that value is
am empty string.  What did I miss?

Bob