Re: org-attach-sync uses directory-empty-p (new in Emacs 28)

[Marco Wahl <marcowahlsoft@gmail.com>]

Maxim Nikulin <manikulin@gmail.com> writes:

> On 11/08/2021 03:52, Marco Wahl wrote:
>>> Kyle Meyer <kyle@kyleam.com> writes:
>>>
>>>> In 61e083732 (org-attach: Possibly delete empty attach directory,
>>>> 2021-07-09), you added a call to directory-empty-p.  This function was
>>>> introduced in Emacs's 0806075520 (Add directory-empty-p and new argument
>>>> COUNT for directory-files-*, 2020-11-02) and hasn't yet made it into a
>>>> release.
>>>>
>>>> Could you update org-attach-sync to avoid using directory-empty-p (e.g.,
>>>> by inlining it or by adding a compatibility alias)?
>> Starting from Arthur's suggestion and Kyle's hint to the
>> compatibility
>> alias I put org-directory-empty-p into org-compat.el.  So there is
>> org-directory-empty-p now which provides the functionality of
>> directory-empty-p from Emacs 28 for smaller version Emacsen.
>
> Unfortunately current code causes a compiler warning at least when
> Emacs-25.2 is used:
>
> Compiling single /home/ubuntu/org-mode/lisp/org-compat.el...
>
> In end of data:
> org-compat.el:1255:1:Warning: the function ‘directory-empty-p’ is not
> known to
>     be defined.

Thanks.

How make the compiler happy?

What about adding a declare-function for directory-empty-p?  Suggestion
for org-compat.el:

#+begin_src emacs-lisp
;;; Emacs < 28.1 compatibility
(if (version< emacs-version "28")
    (defun org-directory-empty-p (dir)
      "Return t if DIR names an existing directory containing no other files."
      (and (file-directory-p dir)
           (null (directory-files dir nil directory-files-no-dot-files-regexp t))))
  (declare-function directory-empty-p "files" (dir)) ; <-- NEW LINE TO MAKE THE COMPILER HAPPY.
  (defalias 'org-directory-empty-p #'directory-empty-p))
#+end_src

Could you please check the compile with this modification?


Best regards,
-- 
Marco