Fix VFOMode to check for correct response

[larsks]

Previous, VFOMode() was expecting the response CHKVFO 1 from rigctld
when running in VFO mode, but in fact rigctld responds with the string
1:

$ nc localhost 4532
\chk_vfo
1

Closes la5nta/pat#427

[martinhpedersen]

Thanks for reporting this, and for the PR :)

This is a breaking API change in rigctld, which is unfortunate. We need to fix this in a backwards compatible way in order to stay compatible with older versions of hamlib.

If we do strings.TrimPrefix(resp, "CHKVFO") == "1" instead, it will work in both cases. Do you mind updating the PR?

Thanks again!

PS: We should probably trace down the change i hamlib and check if this is a bug or an intended API change. Maybe they've done similar changes we shuold take into account aswell.

[larsks]

If we do strings.TrimPrefix(resp, "CHKVFO") == "1" instead, it will work in both cases. Do you mind updating the PR?

Sounds good. I'm happy to update the PR.

We should probably trace down the change in hamlib and check if this is a bug or an intended API change. Maybe they've done similar changes we should take into account as well.

It looks like it changed in Hamlib/Hamlib@44a20c6, without explanation, in Sept 2019.

[martinhpedersen]

That's perfect! Thank you 😀