Temporary work around to make thunderbird subscribe to newsgroups you are not already

subscribed to when clicked on from an external browser. We force the url to get run once the 3-pane window is up.

unfortunately this causes at least 2 new windows to come up. We should try to streamline this by tapping into the
initial command line startup code that creates a window with a url.

mail/base/content/msgMail3PaneWindow.js

@@ -868,7 +868,12 @@ function loadStartFolder(initialUri)
             }
         }
 
-        var startFolder = startFolderResource.QueryInterface(Components.interfaces.nsIMsgFolder);
+        var startFolder = startFolderResource.QueryInterface(Components.interfaces.nsIMsgFolder);
+
+        // it is possible we were given an initial uri and we need to subscribe or try to add
+        // the folder. i.e. the user just clicked on a news folder they aren't subscribed to from a browser
+        // the news url comes in here.   
+
         SelectFolder(startFolder.URI);        
 
         // only do this on startup, when we pass in null
@@ -889,9 +894,16 @@ function loadStartFolder(initialUri)
         PerformExpandForAllOpenServers();
     }
     catch(ex)
-    {
-        dump(ex);
-        dump('Exception in LoadStartFolder caused by no default account.  We know about this\n');
+    {
+
+      if (initialUri)
+      {
+        messenger.loadURL(window, initialUri);
+        return;
+      }
+
+      dump(ex);
+      dump('Exception in LoadStartFolder caused by no default account.  We know about this\n');
     }
 
     MsgGetMessagesForAllServers(defaultServer);