fix for #103681 (no status messages when doing pop).

back out my bad fix for #102978.  we set the msg window on the folder datasource
and we've got a folder datasource per msg window.  by moving this from js to xul,
it made it so we'd set the msg window on one folder ds, and we'd be using the other one.

r/sr=bienvenu

mailnews/base/resources/content/folderPane.xul

@@ -37,8 +37,7 @@
             flex="1"
             seltype="single">
     <outlinerbody flex="1"
-                  datasources="rdf:msgaccountmanager rdf:mailnewsfolders"
-                  ref="msgaccounts:/"
+                  datasources="rdf:null"
                   statedatasource="rdf:mailnewsfolders"
                   ondraggesture="return BeginDragFolderOutliner(event);"
                   onselect="FolderPaneSelectionChange();">

mailnews/base/resources/content/msgMail3PaneWindow.js

@@ -718,7 +718,16 @@ function OnLoadFolderPane()
 
     SortFolderPane("folderNameCol");
 
+    //Add folderDataSource and accountManagerDataSource to folderPane
+    accountManagerDataSource = accountManagerDataSource.QueryInterface(Components.interfaces.nsIRDFDataSource);
+    folderDataSource = folderDataSource.QueryInterface(Components.interfaces.nsIRDFDataSource);
+    var database = GetFolderDatasource();
+
+    database.AddDataSource(accountManagerDataSource);
+    database.AddDataSource(folderDataSource);
     var folderOutliner = GetFolderOutliner();
+    folderOutliner.outlinerBoxObject.outlinerBody.setAttribute("ref", "msgaccounts:/");
+
     var folderOutlinerBuilder = folderOutliner.outlinerBoxObject.outlinerBody.builder.QueryInterface(Components.interfaces.nsIXULOutlinerBuilder);
     folderOutlinerBuilder.addObserver(folderObserver);
     folderOutliner.addEventListener("click",FolderPaneOnClick,true);