Fix factory-reset-app

[sosthene-nitrokey]

Factory-reset-app did not fully delete the PINs of the application.

This PR fixes that.

[robin-nitrokey]

This PR is still based on the superseded #29.

[robin-nitrokey]

I find this entire function very hard to read. I would suggest to extract one function that decides whether the object should be deleted, and one function that performs the actual deletion. Also it would be good to have a comment explaining the logic.

This condition evaluates to internal || (external && delete_keys) if I read it correctly, but I think it should be (internal || external) && delete_keys, no?

[sosthene-nitrokey]

Hmm, right, that condition was indeed incorrect.

I did not split the function fully like you recommended because that would require a lot of reference passing for the counters and everything, but I did simplify it significantly to make it clearer and extracted intermediate values to make their meaning clearer.

I also moved the if statements from the match patterns to the match arms so what they do is more explicit and make it more visible that no case is missing.

[robin-nitrokey]

Thank you, that’s much better! One final comment: AFAIS the locations only apply to the keys and PINs are always deleted regardless of the location. So I think renaming locations to key_locations would be even clearer.