--- loncom/lonnet/perl/lonnet.pm	2022/09/13 12:22:15	1.1491
+++ loncom/lonnet/perl/lonnet.pm	2022/09/18 22:33:45	1.1492
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1491 2022/09/13 12:22:15 raeburn Exp $
+# $Id: lonnet.pm,v 1.1492 2022/09/18 22:33:45 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -2707,6 +2707,8 @@ sub get_domain_defaults {
         $domdefaults{'timezone_def'} = $domconfig{'defaults'}{'timezone_def'};
         $domdefaults{'datelocale_def'} = $domconfig{'defaults'}{'datelocale_def'};
         $domdefaults{'portal_def'} = $domconfig{'defaults'}{'portal_def'};
+        $domdefaults{'portal_def_email'} = $domconfig{'defaults'}{'portal_def_email'};
+        $domdefaults{'portal_def_web'} = $domconfig{'defaults'}{'portal_def_web'};
         $domdefaults{'intauth_cost'} = $domconfig{'defaults'}{'intauth_cost'};
         $domdefaults{'intauth_switch'} = $domconfig{'defaults'}{'intauth_switch'};
         $domdefaults{'intauth_check'} = $domconfig{'defaults'}{'intauth_check'};
@@ -2967,6 +2969,26 @@ sub course_portal_url {
     return $firsturl;
 }
 
+sub url_prefix {
+    my ($r,$dom,$home,$context) = @_;
+    my $prefix;
+    my %domdefs = &get_domain_defaults($dom);
+    if ($domdefs{'portal_def'} && $domdefs{'portal_def_'.$context}) {
+        if ($domdefs{'portal_def'} =~ m{^(https?://[^/]+)}) {
+            $prefix = $1;
+        }
+    }
+    if ($prefix eq '') {
+        my $hostname = &hostname($home);
+        my $protocol = $protocol{$home};
+        $protocol = 'http' if ($protocol{$home} ne 'https');
+        my $alias = &use_proxy_alias($r,$home);
+        $hostname = $alias if ($alias ne '');
+        $prefix = $protocol.'://'.$hostname;
+    }
+    return $prefix;
+}
+
 # --------------------------------------------- Get domain config for passwords
 
 sub get_passwdconf {