Issue 3223 - Implement context menu fallback for SeaMonkey Mail and Thunderbird

lib/child/contextMenu.js

Index: lib/child/contextMenu.js
===================================================================
--- a/lib/child/contextMenu.js
+++ b/lib/child/contextMenu.js
@@ -115,26 +115,25 @@ function getContextInfo(event)
 
   return items;
 };
 
 let ContextMenuObserver =
 {
   observe: function(subject, topic, data)
   {
-    if (topic == "content-contextmenu")
-    {
-      if (subject.wrappedJSObject)
-        subject = subject.wrappedJSObject;
+    if (subject.wrappedJSObject)
+      subject = subject.wrappedJSObject;
 
-      if (subject.addonInfo)
-        subject.addonInfo.adblockplus = getContextInfo(subject.event);
-    }
+    if (subject.addonInfo)
+      subject.addonInfo.adblockplus = getContextInfo(subject.event);
   },
   QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference, Ci.nsIObserver])
 };
 
 let addObserver = Utils.getPropertyWithoutCompatShims(Services.obs, "addObserver");
 addObserver.call(Services.obs, ContextMenuObserver, "content-contextmenu", true);
+addObserver.call(Services.obs, ContextMenuObserver, "AdblockPlus:content-contextmenu", true);
 onShutdown.add(() => {
   let removeObserver = Utils.getPropertyWithoutCompatShims(Services.obs, "removeObserver");
   removeObserver.call(Services.obs, ContextMenuObserver, "content-contextmenu");
+  removeObserver.call(Services.obs, ContextMenuObserver, "AdblockPlus:content-contextmenu");
 });