--- loncom/auth/migrateuser.pm	2021/08/16 15:25:44	1.52
+++ loncom/auth/migrateuser.pm	2021/10/26 14:20:40	1.53
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Starts a user off based of an existing token.
 #
-# $Id: migrateuser.pm,v 1.52 2021/08/16 15:25:44 raeburn Exp $
+# $Id: migrateuser.pm,v 1.53 2021/10/26 14:20:40 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -732,11 +732,11 @@ sub handler {
                 } else {
                     &Apache::lonnet::appenv({'user.linkproturi' => $deeplink});
                 }
-            } elsif ($data{'linkkey'}) {
+            } elsif ($data{'linkkey'} ne '') {
                 &Apache::lonnet::appenv({'request.linkkey' => $data{'linkkey'}});
                 my $deeplink = $data{'deeplink.login'};
                 my $linkkey = $data{'linkkey'};
-                if ($env{'user.deeplinkkey'}) {
+                if ($env{'user.deeplinkkey'} ne '') {
                     my @linkkeys = split(/,/,$env{'user.deeplinkkey'});
                     unless (grep(/^\Q$linkkey\E$/,@linkkeys)) {
                         push(@linkkeys,$linkkey);
@@ -876,7 +876,7 @@ sub handler {
                                           'request.linkprot' => $data{'linkprot'}};
                         }
                     }
-                } elsif ($data{'linkkey'}) {
+                } elsif ($data{'linkkey'} ne '') {
                     if (ref($extra_env) eq 'HASH') {
                         $extra_env->{'user.deeplinkkey'} = $data{'linkkey'};
                         $extra_env->{'user.keyedlinkuri'} = $data{'deeplink.login'};