bug#30938: 27.0; `dired-do-create-files' etc.: do NOT always raise error if no files

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 30 Mar 2018 08:01:42 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: juri@linkov.net, 30938@debbugs.gnu.org
> 
> >   Please provide at least one example (preferably more than one) of a
> >   real-life use case where these changes get in the way.
> > 
> > Without an answer to that, I cannot see why we have to do anything
> > about this issue, because up front I see no problem here at all, not
> > one that has been spelled out.
> 
> I answered your question, pointing to the example of calling
> `dired-do-isearch' (or any of the other such commands)
> non-interactively - e.g., by creating a command that uses it.

I don't see how I was supposed to understand that this as an answer to
my question: my question was not cited, and the text you posted had no
immediate relation to the issue at hand, it just says that
dired-get-marked-files could be called non-interactively, and intended
to do nothing when no files were marked, which is already possible.  I
don't want to guess what that has to do with the issue you raised, and
why.  Please spell that out.

> If you don't believe that a user or another library could
> or would define such a command (or in any other way would
> call an existing function that calls the workhorse function
> `dired-get-marked-files', then too bad.

Such uses can always call dired-get-marked-files with the last
argument nil or omitted.  Where's the problem?