--- loncom/lonnet/perl/lonnet.pm	2017/08/23 22:46:38	1.1351
+++ loncom/lonnet/perl/lonnet.pm	2017/09/25 00:36:35	1.1355
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1351 2017/08/23 22:46:38 raeburn Exp $
+# $Id: lonnet.pm,v 1.1355 2017/09/25 00:36:35 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -650,7 +650,7 @@ sub transfer_profile_to_env {
 
 # ---------------------------------------------------- Check for valid session 
 sub check_for_valid_session {
-    my ($r,$name,$userhashref) = @_;
+    my ($r,$name,$userhashref,$domref) = @_;
     my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
     my ($linkname,$pubname);
     if ($name eq '') {
@@ -678,7 +678,16 @@ sub check_for_valid_session {
     } else {
         $lonidsdir=$r->dir_config('lonIDsDir');
     }
-    return undef if (!-e "$lonidsdir/$handle.id");
+    if (!-e "$lonidsdir/$handle.id") {
+        if ((ref($domref)) && ($name eq 'lonID') && 
+            ($handle =~ /^($match_username)\_\d+\_($match_domain)\_(.+)$/)) {
+            my ($possuname,$possudom,$possuhome) = ($1,$2,$3);
+            if ((&domain($possudom) ne '') && (&homeserver($possuname,$possudom) eq $possuhome)) {
+                $$domref = $possudom;
+            }
+        }
+        return undef;
+    }
 
     my $opened = open(my $idf,'+<',"$lonidsdir/$handle.id");
     return undef if (!$opened);
@@ -3171,6 +3180,71 @@ sub externalssi {
     }
 }
 
+
+# If the local copy of a replicated resource is outdated, trigger a  
+# connection from the homeserver to flush the delayed queue. If no update 
+# happens, remove local copies of outdated resource (and corresponding
+# metadata file).
+
+sub remove_stale_resfile {
+    my ($url) = @_;
+    my $removed;
+    if ($url=~m{^/res/($match_domain)/($match_username)/}) {
+        my $audom = $1;
+        my $auname = $2;
+        unless (($url =~ /\.\d+\.\w+$/) || ($url =~ m{^/res/lib/templates/})) {
+            my $homeserver = &homeserver($auname,$audom);
+            unless (($homeserver eq 'no_host') ||
+                    (grep { $_ eq $homeserver } &current_machine_ids())) {
+                my $fname = &filelocation('',$url);
+                if (-e $fname) {
+                    my $protocol = $protocol{$homeserver};
+                    $protocol = 'http' if ($protocol ne 'https');
+                    my $hostname = &hostname($homeserver);
+                    if ($hostname) {
+                        my $uri = &declutter($url);
+                        my $request=new HTTP::Request('HEAD',$protocol.'://'.$hostname.'/raw/'.$uri);
+                        my $response = &LONCAPA::LWPReq::makerequest($homeserver,$request,'',\%perlvar,5,0,1);
+                        if ($response->is_success()) {
+                            my $remmodtime = &HTTP::Date::str2time( $response->header('Last-modified') );
+                            my $locmodtime = (stat($fname))[9];
+                            if ($locmodtime < $remmodtime) {
+                                my $stale;
+                                my $answer = &reply('pong',$homeserver);
+                                if ($answer eq $homeserver.':'.$perlvar{'lonHostID'}) {
+                                    sleep(0.2);
+                                    $locmodtime = (stat($fname))[9];
+                                    if ($locmodtime < $remmodtime) {
+                                        my $posstransfer = $fname.'.in.transfer';
+                                        if ((-e $posstransfer) && ($remmodtime < (stat($posstransfer))[9])) {
+                                            $removed = 1;
+                                        } else {
+                                            $stale = 1;
+                                        }
+                                    } else {
+                                        $removed = 1;
+                                    }
+                                } else {
+                                    $stale = 1;
+                                }
+                                if ($stale) {
+                                    unlink($fname);
+                                    if ($uri!~/\.meta$/) {
+                                        unlink($fname.'.meta');
+                                    }
+                                    &reply("unsub:$fname",$homeserver);
+                                    $removed = 1;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return $removed;
+}
+
 # -------------------------------- Allow a /uploaded/ URI to be vouched for
 
 sub allowuploaded {