[gnome-shell] messageTray: Only update keyboardVisible as necessary

[Florian MÃllner <fmuellner src gnome org>]

commit 6611d639a86ed70d2e281496f94603e21f885b0a
Author: Florian MÃllner <fmuellner gnome org>
Date:   Sat Sep 22 02:30:58 2012 +0200

    messageTray: Only update keyboardVisible as necessary
    
    This fixes a case of _updateState() being called recursively,
    resulting in stray grab()/ungrab() calls the leave the entire
    desktop in a stuck focus state.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683546

 js/ui/messageTray.js |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/messageTray.js b/js/ui/messageTray.js
index ea4b472..7f76b95 100644
--- a/js/ui/messageTray.js
+++ b/js/ui/messageTray.js
@@ -1868,6 +1868,9 @@ const MessageTray = new Lang.Class({
     },
 
     _onKeyboardVisibleChanged: function(layoutManager, keyboardVisible) {
+        if (this._keyboardVisible == keyboardVisible)
+            return;
+
         this._keyboardVisible = keyboardVisible;
 
         if (keyboardVisible)