--- loncom/lond	2019/07/02 19:40:18	1.559
+++ loncom/lond	2019/07/18 18:28:40	1.560
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.559 2019/07/02 19:40:18 raeburn Exp $
+# $Id: lond,v 1.560 2019/07/18 18:28:40 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: 1.559 $'; #' stupid emacs
+my $VERSION='$Revision: 1.560 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -227,6 +227,7 @@ my %trust = (
                dcmailput => {remote => 1, domroles => 1},
                del => {remote => 1, domroles => 1, enroll => 1, content => 1},
                delbalcookie => {institutiononly => 1},
+               delusersession => {institutiononly => 1},
                deldom => {remote => 1, domroles => 1}, # not currently used
                devalidatecache => {institutiononly => 1},
                domroleput => {remote => 1, enroll => 1},
@@ -3033,6 +3034,54 @@ sub user_has_session_handler {
 }
 &register_handler("userhassession", \&user_has_session_handler, 0,1,0);
 
+sub del_usersession_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $result;
+    my ($udom, $uname) = map { &unescape($_) } (split(/:/, $tail));
+    if (($udom =~ /^$LONCAPA::match_domain$/) && ($uname =~ /^$LONCAPA::match_username$/)) {
+        my $lonidsdir = $perlvar{'lonIDsDir'};
+        if (-d $lonidsdir) {
+            if (opendir(DIR,$lonidsdir)) {
+                my $filename;
+                while ($filename=readdir(DIR)) {
+                    if ($filename=~/^\Q$uname\E_\d+_\Q$udom\E_/) {
+                        if (tie(my %oldenv,'GDBM_File',"$lonidsdir/$filename",
+                                &GDBM_READER(),0640)) {
+                            my $linkedfile;
+                            if (exists($oldenv{'user.linkedenv'})) {
+                                $linkedfile = $oldenv{'user.linkedenv'};
+                            }
+                            untie(%oldenv);
+                            $result = unlink("$lonidsdir/$filename");
+                            if ($result) {
+                                if ($linkedfile =~ /^[a-f0-9]+_linked$/) {
+                                    if (-l "$lonidsdir/$linkedfile.id") {
+                                        unlink("$lonidsdir/$linkedfile.id");
+                                    }
+                                }
+                            }
+                        } else {
+                            $result = unlink("$lonidsdir/$filename");
+                        }
+                        last;
+                    }
+                }
+            }
+        }
+        if ($result == 1) {
+            &Reply($client, "$result\n", "$cmd:$tail");
+        } else {
+            &Reply($client, "not_found\n", "$cmd:$tail");
+        }
+    } else {
+        &Failure($client, "invalid_user\n", "$cmd:$tail");
+    }
+    return 1;
+}
+
+&register_handler("delusersession", \&del_usersession_handler, 0,1,0);
+
 #
 #  Authenticate access to a user file by checking that the token the user's 
 #  passed also exists in their session file