=== modified file 'moodle/lang/en_utf8/moodle.php'
--- old/moodle/lang/en_utf8/moodle.php	2009-11-05 03:34:11 +0000
+++ new/moodle/lang/en_utf8/moodle.php	2009-11-09 02:26:33 +0000
@@ -436,6 +436,7 @@
 $string['deletingcourse'] = 'Deleting $a';
 $string['deletingexistingcoursedata'] = 'Deleting existing course data';
 $string['deletingolddata'] = 'Deleting old data';
+$string['deniedlogin'] = 'Login access denied.';
 $string['department'] = 'Department';
 $string['desc'] = 'Descending';
 $string['description'] = 'Description';
@@ -921,6 +922,7 @@
 $string['loginalready'] = 'You are already logged in';
 $string['loginas'] = 'Login as';
 $string['loginaspasswordexplain'] = '<p>You must enter the special \"loginas password\" to use this feature.<br />If you do not know it, ask your server administrator.</p>';
+$string['loginerror'] = 'Login error. Please contact your site administrator.';
 $string['loginguest'] = 'Login as a guest';
 $string['loginsite'] = 'Login to the site';
 $string['loginsteps'] = 'Hi! For full access to courses you\'ll need to take

=== modified file 'moodle/lib/moodlelib.php'
--- old/moodle/lib/moodlelib.php	2009-11-05 03:34:11 +0000
+++ new/moodle/lib/moodlelib.php	2009-11-09 02:20:28 +0000
@@ -3519,10 +3519,13 @@
     foreach ($auths as $auth) {
         $authplugin = get_auth_plugin($auth);
 
-        // on auth fail fall through to the next plugin
-        if (!$authplugin->user_login($username, $password)) {
-            continue;
-        }
+        // on AUTH_FAIL (or 'false', for backward-compat) fall through to the next plugin
+        $rc = $authplugin->user_login($username, $password);
+	if ($rc === false or $rc === AUTH_FAIL) {
+	    continue;
+	} elseif ($rc === AUTH_DENIED) {
+	    return $rc;
+	}
 
         // successful authentication
         if ($user->id) {                          // User already exists in database

=== modified file 'moodle/login/index.php'
--- old/moodle/login/index.php	2009-11-05 03:34:11 +0000
+++ new/moodle/login/index.php	2009-11-09 02:23:57 +0000
@@ -135,7 +135,7 @@
     }
     update_login_count();
 
-    if ($user) {
+    if (is_object($user)) {
 
         // language setup
         if ($user->username == 'guest') {
@@ -226,9 +226,15 @@
         exit;
 
     } else {
-        if (empty($errormsg)) {
+        if ($user === AUTH_FAIL or $user === false) {
             $errormsg = get_string("invalidlogin");
             $errorcode = 3;
+        } elseif ($user === AUTH_DENIED) {
+            $errormsg = get_string("deniedlogin");
+            $errorcode = 5;
+        } elseif ($user === AUTH_ERROR or empty($errormsg)) {
+            $errormsg = get_string("loginerror");
+            $errorcode = 6;
         }
 
         // TODO: if the user failed to authenticate, check if the username corresponds to a remote mnet user