[orca] Make sure we have an event before checking its type

[Joanmarie Diggs <joanied src gnome org>]

commit a93403e591995e6b7a86e968549a18514e70ae40
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Mon Apr 25 12:43:00 2022 +0200

    Make sure we have an event before checking its type

 src/orca/scripts/apps/gnome-shell/script.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/orca/scripts/apps/gnome-shell/script.py b/src/orca/scripts/apps/gnome-shell/script.py
index f7922dfde..7e086238f 100644
--- a/src/orca/scripts/apps/gnome-shell/script.py
+++ b/src/orca/scripts/apps/gnome-shell/script.py
@@ -75,7 +75,7 @@ class Script(clutter.Script):
         return clutter.Script.skipObjectEvent(self, event)
 
     def locusOfFocusChanged(self, event, oldFocus, newFocus):
-        if (event.type == "window:activate" and newFocus and not newFocus.name):
+        if (event and event.type == "window:activate" and newFocus and not newFocus.name):
             if self._getQueuedEvent("object:state-changed:focused", True):
                 msg = "GNOME SHELL: Have matching focused event. Not announcing nameless window."
                 debug.println(debug.LEVEL_INFO, msg, True)