bug#28520: bug#28483: 26.0.50; copy-directory does not create directories

[Eli Zaretskii]

> Cc: 28483@debbugs.gnu.org, aaronjensen@gmail.com, 28520-done@debbugs.gnu.org,
>  Adam Plaice <plaice.adam+lists@gmail.com>,
>  Tino Calancha <tino.calancha@gmail.com>
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Wed, 20 Sep 2017 11:59:37 -0700
> 
> Thanks for diagnosing the problem and for the fix. That fix should work, 
> and I think we can improve on it slightly by using (copy-directory file 
> target keep-time parents t), as this makes the cond branch more parallel 
> with the other alternatives and avoids a call to file-name-as-directory. 
> So I installed the attached patch into the emacs-26 branch to do that, 
> and to add a test case for this bug.

Thanks, works for me.