--- loncom/auth/lonlogin.pm	2011/03/03 06:37:30	1.147
+++ loncom/auth/lonlogin.pm	2011/06/11 18:21:07	1.148
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Login Screen
 #
-# $Id: lonlogin.pm,v 1.147 2011/03/03 06:37:30 raeburn Exp $
+# $Id: lonlogin.pm,v 1.148 2011/06/11 18:21:07 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -200,9 +200,13 @@ sub handler {
        'tmpput:'.$ukey.$lkey.'&'.$firsturl.$tokenextras,
        $lonhost);
 
-# ------------------- If we cannot talk to ourselves, we are in serious trouble
+# -- If we cannot talk to ourselves, or hostID does not map to a hostname
+#    we are in serious trouble
 
-    if ($logtoken eq 'con_lost') {
+    if (($logtoken eq 'con_lost') || ($logtoken eq 'no_such_host')) {
+        if ($logtoken eq 'no_such_host') {
+            &Apache::lonnet::logthis('No valid logtoken for log-in page -- unable to determine hostname for hostID: '.$lonhost.'. Check entry in hosts.tab');
+        }
         my $spares='';
 	my $last;
         foreach my $hostid (sort
@@ -213,7 +217,7 @@ sub handler {
 			    keys(%Apache::lonnet::spareid)) {
             next if ($hostid eq $lonhost);
 	    my $hostname = &Apache::lonnet::hostname($hostid);
-	    next if ($last eq $hostname);
+	    next if (($last eq $hostname) || ($hostname eq ''));
             $spares.='<br /><font size="+1"><a href="http://'.
                 $hostname.
                 '/adm/login?domain='.$authdomain.'">'.
@@ -221,7 +225,9 @@ sub handler {
                 ' '.&mt('(preferred)').'</font>'.$/;
 	    $last=$hostname;
         }
-$spares.= '<br />';
+        if ($spares) {
+            $spares.= '<br />';
+        }
 my %all_hostnames = &Apache::lonnet::all_hostnames();
 foreach my $hostid (sort
 		    {
@@ -231,7 +237,7 @@ foreach my $hostid (sort
 		    keys(%all_hostnames)) {
     next if ($hostid eq $lonhost || $Apache::lonnet::spareid{$hostid});
     my $hostname = &Apache::lonnet::hostname($hostid);
-    next if ($last eq $hostname);
+    next if (($last eq $hostname) || ($hostname eq ''));
     $spares.='<br /><a href="http://'.
 	$hostname.
 	'/adm/login?domain='.$authdomain.'">'.
@@ -246,12 +252,15 @@ $r->print(
   .'<body bgcolor="#FFFFFF">'
   .'<h1>'.&mt('The LearningOnline Network with CAPA').'</h1>'
   .'<img src="/adm/lonKaputt/lonlogo_broken.gif" align="right" />'
-  .'<h3>'.&mt('This LON-CAPA server is temporarily not available for login.').'</h3>'
-  .'<p>'.&mt('Please attempt to login to one of the following servers:').'</p>'
-  .$spares
-  .'</body>'
+  .'<h3>'.&mt('This LON-CAPA server is temporarily not available for login.').'</h3>');
+    if ($spares) {
+        $r->print('<p>'.&mt('Please attempt to login to one of the following servers:')
+                 .'</p>'
+                 .$spares);
+    }
+    $r->print('</body>'
   .'</html>'
-);
+    );
 return OK;
 }
 
