[orca/gnome-3-36] Fix crash resulting from nested table cells in LO dialog

[Joanmarie Diggs <joanied src gnome org>]

commit a7ffc73c5967a0034fb6627a6e83df310c45f66b
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed May 27 10:25:03 2020 -0400

    Fix crash resulting from nested table cells in LO dialog

 src/orca/scripts/apps/soffice/braille_generator.py | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/orca/scripts/apps/soffice/braille_generator.py 
b/src/orca/scripts/apps/soffice/braille_generator.py
index 5cf81ab5d..c65faf81f 100644
--- a/src/orca/scripts/apps/soffice/braille_generator.py
+++ b/src/orca/scripts/apps/soffice/braille_generator.py
@@ -89,6 +89,9 @@ class BrailleGenerator(braille_generator.BrailleGenerator):
         return []
 
     def _generateRealTableCell(self, obj, **args):
+        if not self._script.utilities.inDocumentContent(obj):
+            return super()._generateRealTableCell(obj, **args)
+
         if not obj.childCount:
             result = super()._generateRealTableCell(obj, **args)
         else: