--- loncom/auth/lonlogin.pm	2016/08/13 20:11:58	1.158.2.6
+++ loncom/auth/lonlogin.pm	2018/09/04 01:10:29	1.158.2.7
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Login Screen
 #
-# $Id: lonlogin.pm,v 1.158.2.6 2016/08/13 20:11:58 raeburn Exp $
+# $Id: lonlogin.pm,v 1.158.2.7 2018/09/04 01:10:29 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -38,6 +38,7 @@ use Apache::lonlocal;
 use Apache::migrateuser();
 use lib '/home/httpd/lib/perl/';
 use LONCAPA;
+use CGI::Cookie();
  
 sub handler {
     my $r = shift;
@@ -56,9 +57,35 @@ sub handler {
 	return &Apache::migrateuser::handler($r);
     }
 
+# For "public user" - remove any exising "public" cookie, as user really wants to log-in
+    my ($handle,$lonidsdir,$expirepub,$userdom);
+    unless ($r->header_only) {
+        $handle = &Apache::lonnet::check_for_valid_session($r,'lonID',undef,\$userdom);
+        if ($handle ne '') {
+            $lonidsdir=$r->dir_config('lonIDsDir');
+            if ($handle=~/^publicuser\_/) {
+                unlink($r->dir_config('lonIDsDir')."/$handle.id");
+                undef($handle);
+                undef($userdom);
+                $expirepub = 1;
+            }
+        }
+    }
+
     &Apache::loncommon::no_cache($r);
     &Apache::lonlocal::get_language_handle($r);
     &Apache::loncommon::content_type($r,'text/html');
+    if ($expirepub) {
+        my $c = new CGI::Cookie(-name    => 'lonID',
+                                -value   => '',
+                                -expires => '-10y',);
+        $r->header_out('Set-cookie' => $c);
+    } elsif (($handle eq '') && ($userdom ne '')) {
+        my $c = new CGI::Cookie(-name    => 'lonID',
+                                -value   => '',
+                                -expires => '-10y',);
+        $r->headers_out->add('Set-cookie' => $c);
+    }
     $r->send_http_header;
     return OK if $r->header_only;
 
@@ -70,35 +97,44 @@ sub handler {
 	return OK;
     }
 
+#
+# If browser sent an old cookie for which the session file had been removed
+# check if configuration for user's domain has a portal URL set.  If so
+# switch user's log-in to the portal.
+#
+
+    if (($handle eq '') && ($userdom ne '')) {
+        my %domdefaults = &Apache::lonnet::get_domain_defaults($userdom);
+        if ($domdefaults{'portal_def'} =~ /^https?\:/) {
+            my $start_page = &Apache::loncommon::start_page('Switching Server ...',undef,
+                                          {'redirect' => [0,$domdefaults{'portal_def'}],});
+            my $end_page   = &Apache::loncommon::end_page();
+            $r->print($start_page.$end_page);
+            return OK;
+        }
+    }
+
     $env{'form.firsturl'} =~ s/(`)/'/g;
 
 # -------------------------------- Prevent users from attempting to login twice
-    my $handle = &Apache::lonnet::check_for_valid_session($r);
     if ($handle ne '') {
-        my $lonidsdir=$r->dir_config('lonIDsDir');
-        if ($handle=~/^publicuser\_/) {
-# For "public user" - remove it, we apparently really want to login
-	    unlink($r->dir_config('lonIDsDir')."/$handle.id");
-        } else {
-# Indeed, a valid token is found
-            &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
-	    my $start_page = 
-	        &Apache::loncommon::start_page('Already logged in');
-	    my $end_page = 
-	        &Apache::loncommon::end_page();
-            my $dest = '/adm/roles';
-            if ($env{'form.firsturl'} ne '') {
-                $dest = $env{'form.firsturl'}; 
-            }
-	    $r->print(
-                  $start_page
-                 .'<p class="LC_warning">'.&mt('You are already logged in!').'</p>'
-                 .'<p>'.&mt('Please either [_1]continue the current session[_2] or [_3]log out[_4].',
-                  '<a href="'.$dest.'">','</a>','<a href="/adm/logout">','</a>').'</p>'
-                 .$end_page
-                 );
-            return OK;
+        &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
+	my $start_page = 
+	    &Apache::loncommon::start_page('Already logged in');
+	my $end_page = 
+	    &Apache::loncommon::end_page();
+        my $dest = '/adm/roles';
+        if ($env{'form.firsturl'} ne '') {
+            $dest = $env{'form.firsturl'}; 
         }
+	$r->print(
+              $start_page
+             .'<p class="LC_warning">'.&mt('You are already logged in!').'</p>'
+             .'<p>'.&mt('Please either [_1]continue the current session[_2] or [_3]log out[_4].',
+              '<a href="'.$dest.'">','</a>','<a href="/adm/logout">','</a>').'</p>'
+             .$end_page
+             );
+        return OK;
     }
 
 # ---------------------------------------------------- No valid token, continue