CDR Module won't process download when multiple records with the same UniqueID exist

We're running FreePBX version 13.0.192.19 on Centos.  We had an issue where the download link inside the CDR module wouldn't work (it would just bring up a blank page) while the play button would function properly.  The CDR module's version is 13.0.31.

We traced the problem back to the database query that looked up the filename in the first place.  There were two records in the CDR with the same Unique ID, and the first record had an empty recordingfile.  We modified the query found in line 60 of /admin/modules/cdr/page.cdr.php to read the following:

SELECT recordingfile FROM ' . $db_name.'.'.$db_table_name . ' WHERE uniqueid = ? and recordingfile != ""

This solved the problem, but it's a fleeting victory, as the internal version control mechanisms hate that the file was modified, and the next time we run an update on the module my patch will be overwritten.  Is this something that can be added to an official release, or is there a different patch that should have been used instead?