--- loncom/lonnet/perl/lonnet.pm	2017/08/11 00:25:30	1.1349
+++ loncom/lonnet/perl/lonnet.pm	2017/08/23 22:46:38	1.1351
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1349 2017/08/11 00:25:30 raeburn Exp $
+# $Id: lonnet.pm,v 1.1351 2017/08/23 22:46:38 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -3694,12 +3694,12 @@ sub userfileupload {
                          '_'.$env{'user.domain'}.'/pending';
         } elsif (($context eq 'existingfile') || ($context eq 'canceloverwrite')) {
             my ($docuname,$docudom);
-            if ($destudom) {
+            if ($destudom =~ /^$match_domain$/) {
                 $docudom = $destudom;
             } else {
                 $docudom = $env{'user.domain'};
             }
-            if ($destuname) {
+            if ($destuname =~ /^$match_username$/) {
                 $docuname = $destuname;
             } else {
                 $docuname = $env{'user.name'};
@@ -13363,8 +13363,23 @@ sub fetch_dns_checksums {
 	    my ($id,$domain,$role,$name,$protocol,$intdom)=split(/:/,$configline);
 	    $name=~s/\s//g;
 	    if ($id && $domain && $role && $name) {
+                if ((exists($hostname{$id})) && ($hostname{$id} ne '')) {
+                    my $curr = $hostname{$id};
+                    my $skip;
+                    if (ref($name_to_host{$curr}) eq 'ARRAY') {
+                        if (($curr eq $name) && (@{$name_to_host{$curr}} == 1)) {
+                            $skip = 1;
+                        } else {
+                            @{$name_to_host{$curr}} = grep { $_ ne $id } @{$name_to_host{$curr}};
+                        }
+                    }
+                    unless ($skip) {
+                        push(@{$name_to_host{$name}},$id);
+                    }
+                } else {
+                    push(@{$name_to_host{$name}},$id);
+                }
 		$hostname{$id}=$name;
-		push(@{$name_to_host{$name}}, $id);
 		$hostdom{$id}=$domain;
 		if ($role eq 'library') { $libserv{$id}=$name; }
                 if (defined($protocol)) {