[orca] Add a sanity check for broken value-interface implementations

[Joanmarie Diggs <joanied src gnome org>]

commit 33e53411e53bc414b6c0cc8ec11bb467fabb7b9a
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Sun Nov 17 13:34:17 2013 -0500

    Add a sanity check for broken value-interface implementations

 src/orca/scripts/default.py |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/src/orca/scripts/default.py b/src/orca/scripts/default.py
index 80be930..64e7aae 100644
--- a/src/orca/scripts/default.py
+++ b/src/orca/scripts/default.py
@@ -3405,8 +3405,11 @@ class Script(script.Script):
                 lastProgressBarTime = self.lastProgressBarTime[obj]
                 lastProgressBarValue = self.lastProgressBarValue[obj]
                 value = obj.queryValue()
-                if value.maximumValue == value.minimumValue:
-                    # This is a busy indicator and not a real progress bar.
+                try:
+                    if value.maximumValue == value.minimumValue:
+                        # This is a busy indicator and not a real progress bar.
+                        return
+                except:
                     return
                 percentValue = int((value.currentValue / \
                     (value.maximumValue - value.minimumValue)) * 100.0)