[gnome-shell/eos3.8: 131/255] workspace: Protect against NULL apps

[Matthew Leeds <mwleeds src gnome org>]

commit 8cb85a90f8913c296731a255eb4a50545de06704
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Jul 24 10:48:45 2019 -0300

    workspace: Protect against NULL apps
    
    Under some (unknown) circumstances, Shell.WindowTracker's
    get_window_app() method may return NULL. The code under
    workspace.js is not robust against that. This is reproducible
    with Minetest.
    
    Check for a NULL app, and return an empty title when that's
    the case, before trying to retrieve the app title.
    
    https://phabricator.endlessm.com/T27263

 js/ui/workspace.js | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index c995ff7693..29ff65e00f 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -641,6 +641,8 @@ var WindowOverlay = class {
 
         let tracker = Shell.WindowTracker.get_default();
         let app = tracker.get_window_app(metaWindow);
+        if (!app)
+            return '';
         return app.get_name();
     }