[orca] Another sanity check in the battle with our nemesis, Dead Accessible.

[Joanmarie Diggs <joanied src gnome org>]

commit d4b0f6076cf2b6092ad204db152e2ffcd66e282d
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Mon Dec 26 22:16:44 2011 -0500

    Another sanity check in the battle with our nemesis, Dead Accessible.

 src/orca/event_manager.py |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/orca/event_manager.py b/src/orca/event_manager.py
index a02add0..8c90392 100644
--- a/src/orca/event_manager.py
+++ b/src/orca/event_manager.py
@@ -409,6 +409,9 @@ class EventManager:
         of debugging).
         """
 
+        if not event.source:
+            return False, "event.source? What event.source??"
+
         if not script:
             script = self._getScriptForEvent(event)