Doctrine event listener could persist a null value

In the current docs if say the product name is updated it looks like the fileName would be null meaning if a product alread has a brichure it would be removed?

Author: matt9mg

controller/upload_file.rst

@@ -365,9 +365,8 @@ automatically upload the file when persisting the entity::
             // only upload new files
             if ($file instanceof UploadedFile) {
                 $fileName = $this->uploader->upload($file);
+                $entity->setBrochure($fileName);
             }
-
-            $entity->setBrochure($fileName);
         }
     }