Bug 257026 - Stop pref-manager calling observers for prefs it doesn't know (fixes hang when joining channels with URLs in the topic).

ChatZilla only.
r=rginda


git-svn-id: svn://10.0.0.236/trunk@166870 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/extensions/irc/js/lib/pref-manager.js

@@ -141,6 +141,10 @@ function pm_removeobserver(observer)
 PrefManager.prototype.onPrefChanged =
 function pm_prefchanged(prefName, realValue, oldValue)
 {
+    // We're only interested in prefs we actually know about.
+    if (!(prefName in this.prefRecords))
+        return;
+
     for (var i = 0; i < this.observers.length; i++)
         this.observers[i].onPrefChanged(prefName, realValue, oldValue);
 }