[gnome-shell] Fix for screenshots when pictures path is unavailable

[Marge Bot <marge-bot src gnome org>]

commit f9652aab82fbb3f9ef8cde3dce84f0e35510e250
Author: Brion Vibber <bvibber wikimedia org>
Date:   Wed Dec 18 14:34:45 2019 -0800

    Fix for screenshots when pictures path is unavailable
    
    On my local jhbuild setup some local stuff is not set up and
    there's no pictures folder. This fixes a regression where it
    blew up instead of saving to the home dir in this situation.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1658>

 js/ui/screenshot.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/ui/screenshot.js b/js/ui/screenshot.js
index 8a92c62130..f10c68f386 100644
--- a/js/ui/screenshot.js
+++ b/js/ui/screenshot.js
@@ -84,7 +84,7 @@ var ScreenshotService = class {
         let path = [
             GLib.get_user_special_dir(GLib.UserDirectory.DIRECTORY_PICTURES),
             GLib.get_home_dir(),
-        ].find(p => GLib.file_test(p, GLib.FileTest.EXISTS));
+        ].find(p => p && GLib.file_test(p, GLib.FileTest.EXISTS));
 
         if (!path)
             return null;