Index: FeedSet.php
===================================================================
--- FeedSet.php	(Revision 19126)
+++ FeedSet.php	(Arbeitskopie)
@@ -89,7 +89,14 @@
     {
         if (!Zend_Uri::check($link)) {
             if (!is_null($uri)) {
-                $link = rtrim($uri, '/') . '/' . ltrim($link, '/');
+                $uri = Zend_Uri::factory($uri);
+
+                if ($link[0] !== '/') {
+                    $link = $uri->getPath() . '/' . $link;
+                }
+
+                $link = $uri->getScheme() . '://' . $uri->getHost() . '/' . $this->_canonicalizePath($link);
+
                 if (!Zend_Uri::check($link)) {
                     $link = null;
                 }
@@ -99,6 +106,26 @@
     }
 
     /**
+     *  Canonicalize relative path
+     */
+    protected function _canonicalizePath($path)
+    {
+        $parts = array_filter(explode('/', $path));
+        $absolutes = array();
+        foreach ($parts as $part) {
+            if ('.' == $part) {
+                continue;
+            }
+            if ('..' == $part) {
+                array_pop($absolutes);
+            } else {
+                $absolutes[] = $part;
+            }
+        }
+        return implode('/', $absolutes);
+    }
+
+    /**
      * Supports lazy loading of feeds using Zend_Feed_Reader::import() but
      * delegates any other operations to the parent class.
      *