Fix desktop environment check on Ubuntu

* lisp/image/wallpaper.el (xdg): Require.
(wallpaper--check-command): Use xdg-current-desktop instead of reading
XDG_CURRENT_DESKTOP directly.  This fixes things on e.g. Ubuntu, where
XDG_CURRENT_DESKTOP might contain a string like "ubuntu:GNOME".

diff --git a/lisp/image/wallpaper.el b/lisp/image/wallpaper.el
index 19741a20f156cbc0ec3917f735f1f624b7b80c93..97789fe3f53b826bea7b55e6aee9761bcd03fb2e 100644 (file)
--- a/lisp/image/wallpaper.el
+++ b/lisp/image/wallpaper.el
@@ -33,6 +33,7 @@
 ;;; Code:
 
 (eval-when-compile (require 'subr-x))
+(require 'xdg)
 
 (defcustom wallpaper-commands
   '(
@@ -85,7 +86,7 @@ You can also use \\[report-emacs-bug]."
            (cdr args))))
 
 (cl-defmethod wallpaper--check-command ((_type (eql 'gsettings)))
-  (equal (getenv "XDG_CURRENT_DESKTOP") "GNOME"))
+  (member "GNOME" (xdg-current-desktop)))
 
 (cl-defmethod wallpaper--check-command ((_type (eql 'swaybg)))
   (and (getenv "WAYLAND_DISPLAY")