[gnome-shell] Fix exception when showing menu for not-running app

[Colin Walters <walters src gnome org>]

commit 90ebcd32e37f10b365d4c02989ce18868598ed66
Author: Colin Walters <walters verbum org>
Date:   Mon Oct 5 16:01:40 2009 -0400

    Fix exception when showing menu for not-running app
    
    Need to check windows.length before checking first window.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=597466

 js/ui/appIcon.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/appIcon.js b/js/ui/appIcon.js
index d7dbd77..760971e 100644
--- a/js/ui/appIcon.js
+++ b/js/ui/appIcon.js
@@ -440,7 +440,7 @@ AppIconMenu.prototype = {
         // Display the app windows menu items and the separator between windows
         // of the current desktop and other windows.
         let activeWorkspace = global.screen.get_active_workspace();
-        let separatorShown = windows[0].get_workspace() != activeWorkspace;
+        let separatorShown = windows.length > 0 && windows[0].get_workspace() != activeWorkspace;
 
         for (let i = 0; i < windows.length; i++) {
             if (!separatorShown && windows[i].get_workspace() != activeWorkspace) {