[orca] Sanity check when getting nesting level of a list

[Joanmarie Diggs <joanied src gnome org>]

commit 1b3f6b63153c602cf4f22ab64ffd65c9c470c432
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Tue Aug 7 13:19:25 2012 +0200

    Sanity check when getting nesting level of a list

 src/orca/script_utilities.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/orca/script_utilities.py b/src/orca/script_utilities.py
index d1db6e3..7b81837 100644
--- a/src/orca/script_utilities.py
+++ b/src/orca/script_utilities.py
@@ -1174,7 +1174,7 @@ class Utilities:
 
         nestingLevel = 0
         parent = obj.parent
-        while parent.parent.getRole() == pyatspi.ROLE_LIST:
+        while parent.parent and parent.parent.getRole() == pyatspi.ROLE_LIST:
             nestingLevel += 1
             parent = parent.parent