Two real findings from review of the identity change.
A pre-v4 entry keeps its serial-keyed unique_id until its first live poll
adopts the UUID, which can be a long while for an appliance that is off
since the entry loads from its snapshot meanwhile. The config flow's UUID
check couldn't see such an entry, so re-adding the same appliance in that
window was waved through as a second entry -- and the two would collide the
moment the older one re-keyed, with rekey_entry resolving the collision by
deleting the duplicate rows, taking the original's entity_ids, history and
automations with them. The flow now also aborts on the legacy key, matched
together with the host so issue #381's two same-serial units at different
addresses stay separable, and gated on CONF_DEVICE_KEY being absent so the
check disappears once the entry has migrated.
Separately, the "nothing stored yet" branch adopted the polled identity
unconditionally, silently dropping the "same IP, different appliance" guard
_run_discovery has had since issue #236 -- and dropping it for precisely
the users who have been running longest. _resolve_identity now computes the
key an entry currently carries once and applies one corroboration rule to
it, so a pre-v4 entry defends itself exactly as a migrated one does.
Adoption still needs no corroboration where there is no identity claim to
defend: an entry keyed on its address (issues #83/#189) or with no stored
serial at all.
Two tests had to change with it, both because their setup was unfaithful
rather than because the behaviour regressed: the two-unit test now has its
devices report the shared serial they actually report, and the offline test
now models a placeholder-serial board, which is where an entry's key and a
snapshot's serial can genuinely disagree.
Three new tests cover the changed behaviour, and the mutation sweep is
extended to thirteen breakages -- including the two guards added here and
the host match that keeps the duplicate check from undoing #381's fix.
Also from review: rename three stale _resolve_key doc references to
_resolve_identity, and stop rebinding new_unique_id in rekey_entry.
Marc Billow
c7aa66ef6e