Add _.gif return from getWebName if image not exists.

File.class.php

@@ -101,7 +101,7 @@ abstract class File
      */
     public function getWebName()
     {
-        return (($this->getIsNoEmpty()) ? ($this->path . '/' . $this->filename) : '');
+        return (($this->getIsNoEmpty()) ? ($this->path . '/' . $this->filename) : '_.gif');
     }
 
     public function __toString()