empty prefix means ""

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@16109 44c647ce-9c0f-0410-b52a-842ac1e357ba

library/Zend/Loader/PluginLoader.php

@@ -122,6 +122,9 @@ class Zend_Loader_PluginLoader implements Zend_Loader_PluginLoader_Interface
      */
     protected function _formatPrefix($prefix)
     {
+    	if($prefix == "") {
+    		return $prefix;
+    	}
         return rtrim($prefix, '_') . '_';
     }