diff --git a/classes/robot/crawler.php b/classes/robot/crawler.php
index 1273d58..f9e35fa 100644
--- a/classes/robot/crawler.php
+++ b/classes/robot/crawler.php
@@ -129,12 +129,12 @@ public function auto_create_bot() {
      * @return string absolute url
      */
     public function absolute_url($base, $rel) {
-        /* return if already absolute URL */
+        // Return if already absolute URL.
         if (parse_url($rel, PHP_URL_SCHEME) != '') {
             return $rel;
         }
 
-        /* queries and anchors */
+        // Handle links which are only queries or anchors.
         if ($rel[0] == '#' || $rel[0] == '?') {
             return $base.$rel;
         }
diff --git a/tests/robot_crawler_test.php b/tests/robot_crawler_test.php
index dadf887..94f14d5 100644
--- a/tests/robot_crawler_test.php
+++ b/tests/robot_crawler_test.php
@@ -48,6 +48,15 @@ protected function setUp() {
      */
     public function provider() {
         return array(
+            // Issue 30
+            // array(
+            //     'base' => 'http://test.com',
+            //     'links' => array(
+            //         '/file.php' => 'http://test.com/file.php',
+            //         '#hash' => 'http://test.com/#hash',
+            //         'http://foo.com' => 'http://foo.com/',
+            //     )
+            // ),
             array(
                 'base' => 'http://test.com/sub/',
                 'links' => array(