--- loncom/lond	2018/08/09 13:27:55	1.546
+++ loncom/lond	2018/08/09 14:07:40	1.547
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.546 2018/08/09 13:27:55 raeburn Exp $
+# $Id: lond,v 1.547 2018/08/09 14:07:40 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -65,7 +65,7 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.546 $'; #' stupid emacs
+my $VERSION='$Revision: 1.547 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -1895,6 +1895,14 @@ sub ls3_handler {
     my $rights;
     my $ulsout='';
     my $ulsfn;
+
+    my ($crscheck,$toplevel,$currdom,$currnum,$skip);
+    unless ($islocal) {
+        my ($major,$minor) = split(/\./,$clientversion);
+        if (($major < 2) || ($major == 2 && $minor < 12)) {
+            $crscheck = 1;
+        }
+    }
     if (-e $ulsdir) {
         if(-d $ulsdir) {
             unless (($getpropath) || ($getuserdir) ||
@@ -1904,8 +1912,26 @@ sub ls3_handler {
                 &Failure($client,"refused\n",$userinput);
                 return 1;
             }
-            if (opendir(LSDIR,$ulsdir)) {
+            if (($crscheck) &&
+                ($ulsdir =~ m{^/home/httpd/html/res/($LONCAPA::match_domain)(/?$|/$LONCAPA::match_courseid)})) {
+                ($currdom,my $posscnum) = ($1,$2);
+                if (($posscnum eq '') || ($posscnum eq '/')) {
+                    $toplevel = 1;
+                } else {
+                    $posscnum =~ s{^/+}{};
+                    if (&LONCAPA::Lond::is_course($currdom,$posscnum)) {
+                        $skip = 1;
+                    }
+                }
+            }
+            if ((!$skip) && (opendir(LSDIR,$ulsdir))) {
                 while ($ulsfn=readdir(LSDIR)) {
+                    if (($crscheck) && ($toplevel) && ($currdom ne '') &&
+                        ($ulsfn =~ /^$LONCAPA::match_courseid$/) && (-d "$ulsdir/$ulsfn")) {
+                        if (&LONCAPA::Lond::is_course($currdom,$ulsfn)) {
+                            next;
+                        }
+                    }
                     undef($obs);
                     undef($rights);
                     my @ulsstats=stat($ulsdir.'/'.$ulsfn);