[orca] Handle starting flat review when cursor offset is after final character

[Joanmarie Diggs <joanied src gnome org>]

commit 5da050aac132e30e749c4e875f9d1821e7c3d938
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Fri Jul 6 16:05:20 2018 -0400

    Handle starting flat review when cursor offset is after final character

 src/orca/flat_review.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/src/orca/flat_review.py b/src/orca/flat_review.py
index d3f640301..ebebf8d12 100644
--- a/src/orca/flat_review.py
+++ b/src/orca/flat_review.py
@@ -230,6 +230,10 @@ class Zone:
             if offset >= 0:
                 return word, offset
 
+        if self.length == charOffset and self.words:
+            lastWord = self.words[-1]
+            return lastWord, lastWord.length
+
         return None, -1
 
     def hasCaret(self):
@@ -879,7 +883,10 @@ class Context:
         elif zone.words:
             current = zone.words[self.wordIndex]
             if flatReviewType == Context.CHAR and current.chars:
-                current = current.chars[self.charIndex]
+                try:
+                    current = current.chars[self.charIndex]
+                except:
+                    return None, -1, -1, -1, -1
 
         return current.string, current.x, current.y, current.width, current.height