So this PHP code works for me:
$ch = curl_init( TCS_CPDF_REMOTE_ZIP );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
$data = curl_exec( $ch );
curl_close( $ch );
file_put_contents( TCS_CPDF_LOCAL_ZIP, $data );
but when trying to use the WordPress HTTP API:
$the_body = wp_remote_retrieve_body( wp_remote_get( TCS_CPDF_REMOTE_ZIP ) );
file_put_contents( TCS_CPDF_LOCAL_ZIP, $the_body );
I end up getting a 0KB file, so the above WordPress version is not working.
So how do you download a file from a remote location using the WordPress API?