RE: empty-directory predicate, native implementation

[Drew Adams]

> > I am using a regular expression from Dired+ by Drew in two places. I
> > have mention it the comment in ert tests, but don't know how to mention
> > it in the example in manual. Maybe remove example, or maybe it can stay
> > without creds?
> 
> You don't need that regexp from Drew. We have the constant
> directory-files-no-dot-files-regexp for that purpose.

FWIW -

`directory-files-no-dot-files-regexp' was added to Emacs 23.
Its value then was the same as that of `diredp-re-no-dot':
"^\\([^.]\\|\\.\\([^.]\\|\\..\\)\\).*".  The value was
changed in Emacs 27, to "[^.]\\|\\.\\.\\.".

For my purposes (Dired) I want the former, not the latter,
so `diredp-re-no-dot' remains the former.  The two behave
quite differently.  

See https://lists.gnu.org/archive/html/emacs-devel/2020-04/msg00764.html