Merge "Fix error when adding text box to site page"

htdocs/artefact/lib.php

@@ -1644,7 +1644,10 @@ function artefact_get_owner_info($ids) {
             $name = display_name($d);
             $url  = 'user/view.php?id=' . $d->id;
         }
-        $d = (object) array('name' => $name, 'url' => $wwwroot . $url);
+        $d = (object) array('name' => $name);
+        if (!empty($url)) {
+            $d->url = $wwwroot . $url;
+        }
     }
     return $data;
 }