bug#44343: 28.0.50; wdired: spurious error message when changing permissions

[Michael Heerdegen]

Hello,

here is the recipe:

#+begin_src emacs-lisp
(require 'wdired)
(setq wdired-allow-to-change-permissions 'advanced)
#+end_src

Then visit some (writable) directory with dired, M-x
wdired-change-to-wdired-mode, and then change a permission bit of some
file.  Then C-c C-c.  I get this error message:

  1 rename actions failed--type ? for details

*Dired log* contains:

| chmod 416 ‘/home/micha/arena.result’ failed
|  
| 1 rename actions failed

Actually there is no need for the error message; changing permission
bits works fine, it succeeds without problems.

But when I read the implementation of `wdired-do-perm-changes'
correctly, it uses the return value of `set-file-modes' to decide
whether setting modes succeeded.  This function always returns nil,
however.

The second, minor issue is that a problem with changing permission bits
is reported as a failed "rename action".


TIA,

Michael.



In GNU Emacs 28.0.50 (build 85, x86_64-pc-linux-gnu, GTK+ Version 3.24.23, 
cairo version 1.16.0)
 of 2020-10-31 built on drachen
Repository revision: f9304de9e09ae621e8790b4f45ab716c43485ce9
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12008000
System Description: Debian GNU/Linux bullseye/sid