--- loncom/interface/lontiny.pm	2024/02/09 20:08:16	1.21
+++ loncom/interface/lontiny.pm	2024/11/17 04:48:15	1.23
@@ -2,7 +2,7 @@
 # Extract domain, courseID, and symb from a shortened URL,
 # and switch role to a role in designated course.
 #
-# $Id: lontiny.pm,v 1.21 2024/02/09 20:08:16 raeburn Exp $
+# $Id: lontiny.pm,v 1.23 2024/11/17 04:48:15 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -99,7 +99,7 @@ sub handler {
                             }
                             if ($env{'request.course.id'} eq $cdom.'_'.$cnum) {
                                 # Check for ttoken
-                                my $newlauncher = &launch_check($r->uri,$symb);
+                                my $newlauncher = &launch_check($r->uri,$symb,$cdom,$cnum);
                                 my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
                                 if (&Apache::lonnet::is_on_map($url)) {
                                     my $realuri;
@@ -307,7 +307,7 @@ sub handler {
 }
 
 sub launch_check {
-    my ($linkuri,$symb) = @_;
+    my ($linkuri,$symb,$cdom,$cnum) = @_;
     my ($linkprotector,$linkproturi,$linkprotexit,$linkprotpbid,$linkprotpburl,
         $linkkey,$newlauncher,$prevlaunch);
     if ($env{'form.ttoken'}) {
@@ -440,35 +440,53 @@ sub launch_check {
                 }
             }
         } else {
-            if (($currdeeplinklogin ne $linkuri) ||
-                (($prevlaunch ne '') && ($currdeeplinklogin ne $prevlaunch))) {
+            unless ($currdeeplinklogin eq $linkuri) {
                 if (($linkprotector) || ($linkkey ne '')) {
-                    if ($linkprotector) {
-                        &Apache::lonnet::appenv({'request.linkprot' => $linkprotector.':'.$linkproturi});
-                    } elsif ($env{'request.linkprot'}) {
-                        &Apache::lonnet::delenv('request.linkprot');
-                    }
+                    $newlauncher = 1;
+                }
+            }
+            if ($linkprotector) {
+                &Apache::lonnet::appenv({'request.linkprot' => $linkprotector.':'.$linkproturi});
+                if ($linkprotpburl && $linkprotpbid) {
+                    my ($res,$error) = &store_passback_info($cdom,$cnum,$linkuri,$linkprotector,
+                                                        $scope,$symb,$linkprotpbid,$linkprotpburl,
+                                                        $currdeeplinklogin);
+                }
+            } elsif ($env{'request.linkprot'}) {
+                &Apache::lonnet::delenv('request.linkprot');
+            }
+            if ($linkkey ne '') {
+                &Apache::lonnet::appenv({'request.linkkey' => $linkkey});
+            } elsif ($env{'request.linkkey'} ne '') {
+                &Apache::lonnet::delenv('request.linkkey');
+            }
+            if (($linkprotector) || ($linkkey ne '')) {
+                if ($linkprotexit ne $env{'request.linkprotexit'}) {
                     if ($linkprotexit) {
                         &Apache::lonnet::appenv({'request.linkprotexit' => $linkprotexit});
                     } elsif ($env{'request.linkprotexit'}) {
                         &Apache::lonnet::delenv('request.linkprotexit');
                     }
+                }
+                if ($linkprotpbid ne $env{'request.linkprotpbid'}) {
                     if ($linkprotpbid) {
                         &Apache::lonnet::appenv({'request.linkprotpbid' => $linkprotpbid});
                     } elsif ($env{'request.linkprotpbid'}) {
                         &Apache::lonnet::delenv('request.linkprotpbid');
                     }
+                }
+                if ($linkprotpburl ne $env{'request.linkprotpburl'}) {
                     if ($linkprotpburl) {
                         &Apache::lonnet::appenv({'request.linkprotpburl' => $linkprotpburl});
                     } elsif ($env{'request.linkprotpburl'}) {
                         &Apache::lonnet::delenv('request.linkprotpburl');
                     }
-                    if ($linkkey ne '') {
-                        &Apache::lonnet::appenv({'request.linkkey' => $linkkey});
-                    } elsif ($env{'request.linkkey'} ne '') {
-                        &Apache::lonnet::delenv('request.linkkey');
+                }
+            } elsif ($prevlaunch) {
+                foreach my $requestkey ('linkprotpbid','linkprotpburl','linkprotexit') {
+                    if ($env{"request.$requestkey"}) {
+                        &Apache::lonnet::delenv("request.$requestkey");
                     }
-                    $newlauncher = 1;
                 }
             }
             &Apache::lonnet::appenv({'request.deeplink.login' => $linkuri});
@@ -512,6 +530,68 @@ sub launch_check {
     return $newlauncher;
 }
 
+#
+# Store linkprotpburl and linkprotpbid in user's nohist_$cid_linkprot_pb.db
+# $linkuri\0$linkprotector\0$scope = [$linkprotpbid,$linkprotpburl]
+# Separately store $symb in course's nohist_linkprot_passback.db
+# which should trigger passback:
+# $symb => {$linkuri\0$linkprotector\0$scope => 1};
+#
+
+sub store_passback_info {
+    my ($cdom,$cnum,$linkuri,$linkprotector,$scope,$symb,
+        $linkprotpbid,$linkprotpburl,$currdeeplinklogin) = @_;
+    my $key = join("\0",($linkuri,$linkprotector,$scope));
+    my $namespace = 'nohist_'.$cdom.'_'.$cnum.'_linkprot_pb';
+    if ($linkuri eq $currdeeplinklogin) {
+        my %pbinfo = &Apache::lonnet::get($namespace,[$key]);
+        if (ref($pbinfo{$key}) eq 'ARRAY') {
+            if (($pbinfo{$key}[0] eq $linkprotpbid) &&
+                ($pbinfo{$key}[1] eq $linkprotpburl)) {
+                return ('ok');
+            }
+        }
+    }
+    my $now = time;
+    my $result = &Apache::lonnet::cput($namespace,{$key => [$linkprotpbid,$linkprotpburl]});
+    my $error;
+    if (($result eq 'ok') || ($result eq 'con_delayed')) {
+        $namespace = 'nohist_linkprot_passback';
+        my %triggers = &Apache::lonnet::get($namespace,[$symb],$cdom,$cnum);
+        my $newtrigger;
+        if ((exists($triggers{$symb})) && (ref($triggers{$symb}) eq 'HASH')) {
+            unless (exists($triggers{$symb}{$key})) {
+                $newtrigger = 1;
+            }
+        } else {
+            $newtrigger = 1;
+        }
+        if ($newtrigger) {
+            my ($lockhash,$tries,$gotlock);
+            $lockhash = {
+                          lock => $env{'user.name'}.
+                                  ':'.$env{'user.domain'},
+                        };
+            $tries = 0;
+            $gotlock = &Apache::lonnet::newput($namespace,$lockhash,$cdom,$cnum);
+            while (($gotlock ne 'ok') && ($tries<10)) {
+                $tries ++;
+                sleep (0.1);
+                $gotlock = &Apache::lonnet::newput($namespace,$lockhash,$cdom,$cnum);
+            }
+            if ($gotlock eq 'ok') {
+                %triggers = &Apache::lonnet::get($namespace,[$symb],$cdom,$cnum);
+                $triggers{$symb}{$key} = 1;
+                $result = &Apache::lonnet::cput($namespace,{$symb => $triggers{$symb}},$cdom,$cnum);
+                my $dellockoutcome = &Apache::lonnet::del($namespace,['lock'],$cdom,$cnum);
+            } else {
+                $error = 'nolock';
+            }
+        }
+    }
+    return ($result,$error);
+}
+
 sub do_redirect {
     my ($r,$destination,$linkprot) = @_;
     my $windowname = 'loncapaclient';