vc-state and unregistered (was: bug#20637: incompatible, undocumented change to vc-working-revision)

[Michael Albinus]

Dmitry Gutov <address@hidden> writes:

Hi Dmitry,

> I don't really see a point in returning `unregistered' from
> `vc-state'. When would the caller treat it differently from nil? And
> returning nil seems like an easier choice, implementation-wise, and
> well as a more conservative one from the backward compatibility
> perspective.

I've checked a little bit more. If we use nil instead of unregistered as
result from vc-state, we cannot use file properties for this function
anymore. nil is meant as "no property set". This would be a regression.

Best regards, Michael.