[orca] Renable preservation of MathML tree when expanding EOCs

[Joanmarie Diggs <joanied src gnome org>]

commit 97cbafdefea6b620ba39757bb229ba90f8f639f0
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed May 23 19:45:44 2018 -0700

    Renable preservation of MathML tree when expanding EOCs
    
    Add sanity check to ensure we have a tree before trying to preserve it

 src/orca/scripts/web/script_utilities.py |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/src/orca/scripts/web/script_utilities.py b/src/orca/scripts/web/script_utilities.py
index 5734113..afc7160 100644
--- a/src/orca/scripts/web/script_utilities.py
+++ b/src/orca/scripts/web/script_utilities.py
@@ -727,6 +727,9 @@ class Utilities(script_utilities.Utilities):
         return [ext.x, ext.y, ext.width, ext.height]
 
     def _preserveTree(self, obj):
+        if not (obj and obj.childCount):
+            return False
+
         if self.isMathTopLevel(obj):
             return True
 
@@ -762,7 +765,7 @@ class Utilities(script_utilities.Utilities):
                     continue
 
                 childText = ""
-                if True or not self._preserveTree(child):
+                if not self._preserveTree(child):
                     childText = self.expandEOCs(child)
                 else:
                     utterances = self._script.speechGenerator.generateSpeech(child)