* filename will be NULL and the function will return success.
*
* @param remote the remote to download from
- * @param filename where to store the temporary filename
+ * @param bytes buffer that receives the number of bytes transferred (updated
+ * while transfer is in progress)
* @param progress_cb function to call with progress information. Be aware that
* this is called inline with network and indexing operations, so performance
* may be affected.