Merge branch '5896-add-a-generic-objectlinkattribute' into '1.4-dev'

Resolve "Add a generic ObjectLinkAttribute"

See merge request fusiondirectory/fd!415

include/simpleplugin/class_Attribute.inc

@@ -909,6 +909,10 @@ class ObjectLinkAttribute extends DisplayLDAPAttribute
 
   function renderFormInput ()
   {
+    if (empty($this->value)) {
+      return '';
+    }
+
     try {
       return objects::link($this->value, $this->type);
     } catch (NonExistingLdapNodeException $e) {