bug#62763: 29.0.90; failed test during build

[Eli Zaretskii]

> From: Tim Heaney <theaney@gmail.com>
> Date: Tue, 11 Apr 2023 09:23:11 -0400
> Cc: 62763@debbugs.gnu.org
> 
> Here is the *Messages* buffer after the first part
> 
> For information about GNU Emacs and the GNU system, type C-h C-a.
> Loading wallpaper...done
> You can run the command ‘load-library’ with M-x loa-l
> Loading wallpaper...done
> #s(wallpaper-setter "XFCE" "xfconf-query" wallpaper-xfce-command-args #[0 "! 
> \0! \0 " [getenv
> "DESKTOP_SESSION" ("xubuntu" "ubuntustudio") "XFCE" xdg-current-desktop] 2] 
> nil nil)

Thanks.  Does the patch below fix the error?

diff --git a/test/lisp/image/wallpaper-tests.el 
b/test/lisp/image/wallpaper-tests.el
index 2e4e360..c4167ad 100644
--- a/test/lisp/image/wallpaper-tests.el
+++ b/test/lisp/image/wallpaper-tests.el
@@ -129,12 +129,16 @@ wallpaper-set/calls-wallpaper-set-function
       (should (equal called fil-jpg)))))
 
 (ert-deftest wallpaper--find-command/return-string ()
-  (should (or (not (wallpaper--find-command))
-              (stringp (wallpaper--find-command)))))
+  (let ((cmd (wallpaper--find-command)))
+    (should (or (not cmd)
+                (stringp cmd)))))
 
 (ert-deftest wallpaper--find-command-args/return-list ()
-  (should (or (not (wallpaper--find-command-args))
-              (listp (wallpaper--find-command-args)))))
+  (let ((cmdargs (wallpaper--find-command-args)))
+    (if (functionp cmdargs)
+        (setq cmdargs (funcall cmdargs)))
+    (should (or (not cmdargs)
+                (listp cmdargs)))))
 
 (ert-deftest wallpaper--image-file-regexp/return-string ()
   (should (stringp (wallpaper--image-file-regexp))))