[gnome-boxes] notificationbar: Fix infinite loop in cancel()

[Christophe Fergeau <teuf src gnome org>]

commit 7a93363e5c97396152a57e9f4fc2a7174bd9632b
Author: Christophe Fergeau <cfergeau redhat com>
Date:   Wed Jan 30 11:20:09 2013 +0100

    notificationbar: Fix infinite loop in cancel()
    
    https://bugzilla.gnome.org/show_bug.cgi?id=681747

 src/notificationbar.vala |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/notificationbar.vala b/src/notificationbar.vala
index 1744cbb..9c1ac4f 100644
--- a/src/notificationbar.vala
+++ b/src/notificationbar.vala
@@ -147,8 +147,10 @@ private class Boxes.Notificationbar: GLib.Object {
 
     public void cancel () {
         // We destroy all active notifications, which will cause them to be dismissed
-        while (active_notifications != null)
+        while (active_notifications != null) {
             active_notifications.data.destroy ();
+            active_notifications.remove (active_notifications.data);
+        }
     }
 
     private void add_notification (Widget w) {