Index: link.module
===================================================================
--- link.module	(revision 657)
+++ link.module	(working copy)
@@ -368,6 +368,7 @@
   $field['attributes'] += _link_default_attributes();
 
   // Merge item attributes with attributes defined at the field level.
+  $item['attributes'] = array_filter($item['attributes']);
   $item['attributes'] += $field['attributes'];
 
   // If user is not allowed to choose target attribute, use default defined at