Chown with dired over Tramp, from Windows machine

Question

I launch dired over Tramp (from Win machine to Linux server):

C-x d /plink:user@server|su:root@server:/path-to-folder-controlled-by-root/

Then I type "O" to chown a folder, but I get chown not supported on this system. Debugging, I can see the error stems from the definition of dired-of-chgrp, which makes the following verification :

  (if (memq system-type '(ms-dos windows-nt))
      (error "chgrp not supported on this system"))

which obviously fails, because my machine is Windows — but I'm not chowning on Windows. Removing these two lines allows me to use the function normally. I have the same issue with chgroup.

Does this mean my setup is incorrect, or is this a limitation? What would be a clean way to correct this? Just removing these two lines seems like a dirty hack.

Answer 1

The proper fix would be

(if (and (memq system-type '(ms-dos windows-nt))
         (not (file-remote-p default-directory)))
    (error "chgrp not supported on this system"))

I've fixed this in the Emacs repository, will appear with Emacs 27.1.