On 09/20/2017 04:26 AM, Eli Zaretskii wrote:
> I think the problem is in this line:
>
> 	  (cond
> 	   ((eq filetype t)       ; Directory but not a symlink.
> 	    (copy-directory file newname keep-time parents)) <<<<<<<<<<<
>
> Instead of 'newname', there should be (file-name-as-directory newname)
> there.  I think.

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. This patch should also fix 
Bug#28520 "Dired recursive copy of directory fails", so I'll CC: that 
bug report and boldly close it.

PS. Sorry, Adam, for misspelling your first name in the commit message. 
I'll try to remember to fix that when it spills out into the ChangeLog file.