Merge Bug #77202 into thunderbird.

mail/base/content/mailWindowOverlay.js

@@ -1990,6 +1990,6 @@ function loadThrobberUrl(urlPref)
     var url;
     try {
         url = gPrefs.getComplexValue(urlPref, Components.interfaces.nsIPrefLocalizedString).data;
-        messenger.loadExternalURL(window, url);  
+        messenger.loadURL(window, url);  
     } catch (ex) {}
 }

mail/base/content/msgMail3PaneWindow.js

@@ -60,6 +60,8 @@ var gRightMouseButtonDown = false;
 // This is used to make sure that the row with the currentIndex has the selection
 // after a Delete or Move of a message that has a row index less than currentIndex.
 var gThreadPaneCurrentSelectedIndex = -1;
+var gLoadStartFolder = true;
+var gNewAccountToLoad = null;
 
 // Global var to keep track of if the 'Delete Message' or 'Move To' thread pane
 // context menu item was triggered.  This helps prevent the tree view from
@@ -791,13 +793,14 @@ function loadStartFolder(initialUri)
         SelectFolder(startFolder.URI);
 
         // only do this on startup, when we pass in null
-        if (!initialUri && isLoginAtStartUpEnabled)
+        if (!initialUri && isLoginAtStartUpEnabled && gLoadStartFolder)
         {
             // Perform biff on the server to check for new mail, except for imap
             if (defaultServer.type != "imap")
               defaultServer.PerformBiff();         
         }
 
+
         // because the "open" state persists, we'll call
         // PerformExpand() for all servers that are open at startup.
         // note, because of the "news.persist_server_open_state_in_folderpane" pref