Org links file name encoding issue

Question

Inspired by John Kitchin's presentation of org-links features in Org-mode 9, I tried to implement a simple functionality for "file" links. Since I am working on several machines, I wanted the link face to show if file exists on disk. So in org-link-set-parameters func for "file" I've put this simple code:

:face '(lambda (path) (if (file-exists-p path)
                          '(:foreground "green")
                        '(:foreground "red")))

It works just fine unless file has Polish characters in its name ("ąęćłóśżź"). Especially after editing the link description with org-insert-link with cursor on the link it's face becomes red (as non existent file), and the path becomes for example like this (assuming the file name is "żółć.org"):

[[file:%C5%BC%C3%B3%C5%82%C4%87.org]]

I was changing the value of file-name-coding-system variable but without any impact for described behaviour.

When I change value of the :follow key to '(lambda (path) (message "%s" (file-exists-p path))) it returns "t". I assume then that it has something to do with filtering file name by different emacs functions but I can't find which would be responsible for wrong behaviour of the ":face" parameter.

I'd appreciate any help to fix that.

Answer 1

Have you tried using org-link-unescape to get back the original filename? Something like:

:face '(lambda (path)
         (if (file-exists-p (org-link-unescape path))
             '(:foreground "green")
           '(:foreground "red"))))

Answer 2

I just tried, and an Org-mode file with this content works just fine:

[[file:żółć.org]]

C-c o works as expected and visits the file. For some reason C-c o works with the escaped characters as in your example, but I get an error Error during redisplay: (jit-lock-function 33) signaled (error "Not enough arguments for format string") [2 times] in *Messages* with your example.