Worked around Fennec bug: selecting a subscription in the list is ignored

lib/ui.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 173 matching lines @@
             if (currentSubscription && url == currentSubscription.url)
               list.selectedIndex = list.itemCount - 1;
 
             if (currentSubscription && list.selectedIndex < 0)
             {
               list.appendItem(currentSubscription.title, currentSubscription.url, null);
               list.selectedIndex = list.itemCount - 1;
             }
           }
 
-          list.addEventListener("command", function(event)
+          var listener = function()
           {
             if (list.value)
               UI.setSubscription(list.value, list.label);
-          }, false);
+          }
+          list.addEventListener("command", listener, false);
+
+          // xul:menulist in Fennec is broken and doesn't trigger any events
+          // on selection. Have to detect selectIndex changes instead.
+          // See http://hg.mozilla.org/mozilla-central/file/04d8c309fe72/mobile/android/chrome/content/SelectHelper.js#l40
+          list.watch("selectedIndex", function(prop, oldval, newval)
+          {
+            Utils.runAsync(listener);
+            return newval;
+          });
         }, false);
         request.send();
       }
     }
   },
 
   observe: function(subject, topic, data)
   {
     let {addonID} = require("info")
     if (data != addonID)
@@ skipping 1724 matching lines @@
   ["abp-command-contribute", "command", UI.openContributePage.bind(UI)],
   ["abp-command-contribute-hide", "command", UI.hideContributeButton.bind(UI)]
 ];
 
 onShutdown.add(function()
 {
   for (let window in UI.applicationWindows)
     if (UI.isBottombarOpen(window))
       UI.toggleBottombar(window);
 });