[orca/gnome-2-30] Fix for bgo#618801 - Traceback in Thunderbird

[Joanmarie Diggs <joanied src gnome org>]

commit 80d99a041d1016e331f440f679e96dfac8d55846
Author: Joanmarie Diggs <joanmarie diggs gmail com>
Date:   Sun May 16 13:57:31 2010 -0400

    Fix for bgo#618801 - Traceback in Thunderbird

 src/orca/scripts/apps/Thunderbird/script.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/orca/scripts/apps/Thunderbird/script.py b/src/orca/scripts/apps/Thunderbird/script.py
index 52352c6..62d0c61 100644
--- a/src/orca/scripts/apps/Thunderbird/script.py
+++ b/src/orca/scripts/apps/Thunderbird/script.py
@@ -389,7 +389,8 @@ class Script(Gecko.Script):
                      pyatspi.ROLE_SCROLL_PANE,
                      pyatspi.ROLE_SCROLL_PANE]
         if self.isDesiredFocusedItem(event.source, rolesList):
-            if isinstance(orca_state.lastInputEvent, input_event.KeyboardEvent):
+            if isinstance(orca_state.lastInputEvent, input_event.KeyboardEvent)\
+               and orca_state.lastNonModifierKeyEvent:
                 string = orca_state.lastNonModifierKeyEvent.event_string
                 if string == "Delete":
                     oldLocusOfFocus = None