--- loncom/auth/lonacc.pm	2019/07/31 17:42:29	1.159.2.7
+++ loncom/auth/lonacc.pm	2020/01/22 18:10:12	1.159.2.8.2.1
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Cookie Based Access Handler
 #
-# $Id: lonacc.pm,v 1.159.2.7 2019/07/31 17:42:29 raeburn Exp $
+# $Id: lonacc.pm,v 1.159.2.8.2.1 2020/01/22 18:10:12 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -332,17 +332,21 @@ sub sso_login {
             ($is_balancer,$otherserver) =
                 &Apache::lonnet::check_loadbalancing($user,$domain,'login');
             if ($is_balancer) {
-                if ($otherserver eq '') {
+                # Check if browser sent a LON-CAPA load balancer cookie (and this is a balancer)
+                my ($found_server,$balancer_cookie) = &Apache::lonnet::check_for_balancer_cookie($r);
+                if (($found_server) && ($balancer_cookie =~ /^\Q$domain\E_\Q$user\E_/)) {
+                    $otherserver = $found_server;
+                } elsif ($otherserver eq '') {
                     my $lowest_load;
                     ($otherserver,undef,undef,undef,$lowest_load) = &Apache::lonnet::choose_server($domain);
                     if ($lowest_load > 100) {
                         $otherserver = &Apache::lonnet::spareserver($lowest_load,$lowest_load,1,$domain);
                     }
-                }
-                if ($otherserver ne '') {
-                    my @hosts = &Apache::lonnet::current_machine_ids();
-                    if (grep(/^\Q$otherserver\E$/,@hosts)) {
-                        $hosthere = $otherserver;
+                    if ($otherserver ne '') {
+                        my @hosts = &Apache::lonnet::current_machine_ids();
+                        if (grep(/^\Q$otherserver\E$/,@hosts)) {
+                            $hosthere = $otherserver;
+                        }
                     }
                 }
             }
@@ -351,6 +355,14 @@ sub sso_login {
 	    # login but immediately go to switch server to find us a new 
 	    # machine
 	    &Apache::lonauth::success($r,$user,$domain,$home,'noredirect');
+            foreach my $item (keys(%form)) {
+                $env{'form.'.$item} = $form{$item};
+            }
+            unless ($form{'symb'}) {
+                unless (($r->uri eq '/adm/roles') || ($r->uri eq '/adm/sso')) {
+                    $env{'form.origurl'} = $r->uri;
+                }
+            }
             $env{'request.sso.login'} = 1;
             if (defined($r->dir_config("lonSSOReloginServer"))) {
                 $env{'request.sso.reloginserver'} =
@@ -537,6 +549,7 @@ sub handler {
             my $lonhost = &Apache::lonnet::host_from_dns($hostname);
             if ($lonhost) {
                 my $actual = &Apache::lonnet::absolute_url($hostname);
+                my $exphostname = &Apache::lonnet::hostname($lonhost);
                 my $expected = $Apache::lonnet::protocol{$lonhost}.'://'.$hostname;
                 unless ($actual eq $expected) {
                     $env{'request.use_absolute'} = $expected;
@@ -552,7 +565,7 @@ sub handler {
         my $checkexempt;
         if ($env{'user.loadbalexempt'} eq $r->dir_config('lonHostID')) {
             if ($env{'user.loadbalcheck.time'} + 600 > time) {
-                $checkexempt = 1;    
+                $checkexempt = 1;
             }
         }
         if ($env{'user.noloadbalance'} eq $r->dir_config('lonHostID')) {
@@ -562,18 +575,32 @@ sub handler {
             ($is_balancer,$otherserver) =
                 &Apache::lonnet::check_loadbalancing($env{'user.name'},
                                                      $env{'user.domain'});
+            if ($is_balancer) {
+                unless (($requrl eq '/adm/switchserver') && (!$r->is_initial_req())) {
+                    # Check if browser sent a LON-CAPA load balancer cookie (and this is a balancer)
+                    my ($found_server,$balancer_cookie) = &Apache::lonnet::check_for_balancer_cookie($r);
+                    if (($found_server) && ($balancer_cookie =~ /^\Q$env{'user.domain'}\E_\Q$env{'user.name'}\E_/)) {
+                        $otherserver = $found_server;
+                    }
+                }
+            }
         }
         if ($is_balancer) {
-            $r->set_handlers('PerlResponseHandler'=>
-                             [\&Apache::switchserver::handler]);
-            if ($otherserver ne '') {
-                $env{'form.otherserver'} = $otherserver;
+            unless (($requrl eq '/adm/switchserver') && (!$r->is_initial_req())) {
+                $r->set_handlers('PerlResponseHandler'=>
+                                 [\&Apache::switchserver::handler]);
+                if ($otherserver ne '') {
+                    $env{'form.otherserver'} = $otherserver;
+                }
             }
             unless (($env{'form.origurl'}) || ($r->uri eq '/adm/roles') ||
                     ($r->uri eq '/adm/switchserver') || ($r->uri eq '/adm/sso')) {
                 $env{'form.origurl'} = $r->uri;
             }
         }
+        if ($requrl=~m{^/+tiny/+$match_domain/+\w+$}) {
+            return OK;
+        }
 
 # ---------------------------------------------------------------- Check access
 	my $now = time;