Index: linkchecker.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/linkchecker/linkchecker.module,v
retrieving revision 1.7.2.139
diff -u -r1.7.2.139 linkchecker.module
--- linkchecker.module	7 Jul 2010 21:41:10 -0000	1.7.2.139
+++ linkchecker.module	8 Sep 2010 06:16:31 -0000
@@ -481,7 +481,10 @@
       if (!empty($node->{$field['field_name']})) {
         if (module_exists('link') && $field['type'] == 'link') {
           foreach ($node->$field['field_name'] as $delta => $item) {
-            $text_items[] = _filter_url($item['url'], $node->format);
+            if (!empty($item['url'])) {
+              // Make non-absolute urls absolute or they are not found by _filter_url().
+              $text_items[] = _filter_url(url($item['url'], array('absolute' => TRUE)), $node->format);
+            }
           }
         }
         elseif (module_exists('text') && $field['type'] == 'text') {