[orca/gnome-3-34] Filter out duplicate dialogs which appear in the accessibility tree twice

[Joanmarie Diggs <joanied src gnome org>]

commit 7a3b9f3db0a4b1a599680d1ed846e6dbe23ff74f
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed Nov 13 13:12:33 2019 -0500

    Filter out duplicate dialogs which appear in the accessibility tree twice

 src/orca/script_utilities.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/orca/script_utilities.py b/src/orca/script_utilities.py
index 0dd41f374..aa2a545f1 100644
--- a/src/orca/script_utilities.py
+++ b/src/orca/script_utilities.py
@@ -2453,7 +2453,7 @@ class Utilities:
         dialogs.extend([x for x in self.topLevelObject(obj) if isDialog(x)])
 
         isPresentable = lambda x: self.isShowingAndVisible(x) and (x.name or x.childCount)
-        presentable = list(filter(isPresentable, dialogs))
+        presentable = list(filter(isPresentable, set(dialogs)))
 
         unfocused = list(filter(lambda x: not self.canBeActiveWindow(x), presentable))
         return len(unfocused)