rem: return IsMailFolderSelected(); 
add: var folderURI = GetSelectedFolderURI(); var server = GetServer(folderURI); return (server.canEmptyTrashOnExit?IsMailFolderSelected():false); 
context: function IsEmptyTrashEnabled(){    return IsMailFolderSelected();}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/0d80ab9fb5505377f232b90eee1ec27d04223fc1/mailWindowOverlay.js/buggy/mailnews/base/resources/content/mailWindowOverlay.js