--- js/gdm/loginDialog.js.shells	2013-07-31 02:23:04.000000000 +0400

+++ js/gdm/loginDialog.js	2013-07-31 10:31:18.338968456 +0400

@@ -241,6 +241,12 @@

         if (user.locked)

            return;

+	let userShell = user.get_shell();

+

+	if (userShell == '/dev/null' ||

+	   userShell == '/bin/false')

+	    return;

+

         let userName = user.get_user_name();

         if (!userName)