use of incorrect service: registration_codes

I found one more place that had that same problem.

I also wrote some test cases to make sure the replacement of the procedural functions with service methods was done properly. That's something I would normally do but didn't do for this module because there are so few people using the module and because writing the tests is an annoying amount of boilerplate work. But since you found a problem, the tests will ensure that there are no other hidden problems here.

As I said, an annoying amount of boilerplate work. But the tests are working now.

Meant "Needs review"

Automatically closed - issue fixed for 2 weeks with no activity.