--- loncom/lonnet/perl/lonnet.pm	2020/10/15 18:09:10	1.1428
+++ loncom/lonnet/perl/lonnet.pm	2020/10/22 19:23:23	1.1431
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1428 2020/10/15 18:09:10 raeburn Exp $
+# $Id: lonnet.pm,v 1.1431 2020/10/22 19:23:23 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1150,6 +1150,21 @@ sub check_for_balancer_cookie {
     return ($otherserver,$cookie);
 }
 
+sub updatebalcookie {
+    my ($cookie,$balancer,$lastentry)=@_;
+    if ($cookie =~ /^($match_domain)\_($match_username)\_[a-f0-9]{32}$/) {
+        my ($udom,$uname) = ($1,$2);
+        my $uprimary_id = &domain($udom,'primary');
+        my $uintdom = &internet_dom($uprimary_id);
+        my $intdom = &internet_dom($balancer);
+        my $serverhomedom = &host_domain($balancer);
+        if (($uintdom ne '') && ($uintdom eq $intdom)) {
+            return &reply('updatebalcookie:'.&escape($cookie).':'.&escape($lastentry),$balancer);
+        }
+    }
+    return;
+}
+
 sub delbalcookie {
     my ($cookie,$balancer) =@_;
     if ($cookie =~ /^($match_domain)\_($match_username)\_[a-f0-9]{32}$/) {
@@ -1159,7 +1174,7 @@ sub delbalcookie {
         my $intdom = &internet_dom($balancer);
         my $serverhomedom = &host_domain($balancer);
         if (($uintdom ne '') && ($uintdom eq $intdom)) {
-            return &reply("delbalcookie:$cookie",$balancer);
+            return &reply('delbalcookie:'.&escape($cookie),$balancer);
         }
     }
 }
@@ -1646,7 +1661,7 @@ sub check_loadbalancing {
     if ($domneedscache) {
         &do_cache_new('loadbalancing',$domneedscache,$is_balancer,$cachetime);
     }
-    if ($is_balancer) {
+    if (($is_balancer) && ($caller ne 'switchserver')) {
         my $lowest_load = 30000;
         if (ref($offloadto) eq 'HASH') {
             if (ref($offloadto->{'primary'}) eq 'ARRAY') {
@@ -1686,9 +1701,9 @@ sub check_loadbalancing {
                 }
             }
         }
-        unless ($homeintdom) {
-            undef($setcookie);
-        }
+    }
+    if (($is_balancer) && (!$homeintdom)) {
+        undef($setcookie);
     }
     return ($is_balancer,$otherserver,$setcookie,$offloadto,$dom_balancers);
 }
@@ -8767,16 +8782,18 @@ sub get_commblock_resources {
                                         my $first = $mapres->map_start();
                                         my $finish = $mapres->map_finish();
                                         my $it = $navmap->getIterator($first,$finish,undef,0,0);
-                                        my $res;
-                                        while ($res = $it->next(undef,1)) {
-                                            next unless (ref($res));
-                                            my $symb = $res->symb();
-                                            next if (($symb eq $mapsymb) || ($symb eq ''));
-                                            @interval=&EXT("resource.0.interval",$symb);
-                                            if ($interval[1] eq 'map') {
-                                                if ($res->answerable()) {
-                                                    push(@to_test,$res);
-                                                    last;
+                                        if (ref($it)) {
+                                            my $res;
+                                            while ($res = $it->next(undef,1)) {
+                                                next unless (ref($res));
+                                                my $symb = $res->symb();
+                                                next if (($symb eq $mapsymb) || ($symb eq ''));
+                                                @interval=&EXT("resource.0.interval",$symb);
+                                                if ($interval[1] eq 'map') {
+                                                    if ($res->answerable()) {
+                                                        push(@to_test,$res);
+                                                        last;
+                                                    }
                                                 }
                                             }
                                         }