[orca] Handle MathML mmultiscripts element which lacks mprescripts element

[Joanmarie Diggs <joanied src gnome org>]

commit 24c99f3246d6eafc2ffd96e155d3f4a79c52c11a
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Thu Jul 2 05:31:51 2015 -0400

    Handle MathML mmultiscripts element which lacks mprescripts element

 src/orca/scripts/web/script_utilities.py |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/src/orca/scripts/web/script_utilities.py b/src/orca/scripts/web/script_utilities.py
index d037008..06f0885 100644
--- a/src/orca/scripts/web/script_utilities.py
+++ b/src/orca/scripts/web/script_utilities.py
@@ -1650,10 +1650,11 @@ class Utilities(script_utilities.Utilities):
 
     def getMathPostscripts(self, obj):
         separator = self._getMathPrePostScriptSeparator(obj)
-        if not separator:
-            return []
+        if separator:
+            index = separator.getIndexInParent()
+        else:
+            index = obj.childCount
 
-        index = separator.getIndexInParent()
         return [obj[i] for i in range(1, index)]
 
     def getMathEnclosures(self, obj):