App reinstalls that preserve data (Android Studio installDebug over an
existing install) re-register with the same device_identifier, but the
devices row from the previous install still exists — device_identifier
is UNIQUE, so ApproveDevice's blind INSERT failed with a unique
violation and returned 500 'failed to create device' (reproduced via
curl: second approve with the same identifier = instant 500; the ~98s
in the original report was app-side retry/polling, not server wait).
ApproveDevice is now idempotent: look the device up by identifier
first; a row owned by the approving user gets its auth token rotated
via UpdateDeviceAuthToken (row id unchanged, so synced highlights/
bookmarks/progress anchored to it stay valid; fresh install = fresh
credentials, old token invalidated); a row owned by another user gets
409; unknown identifiers INSERT as before, with the 23505 race falling
through to the rotate path. DB failures are logged (they were silent).
Also guard the in-memory pendingRegistrations map with a mutex —
register/approve/reject/status/list all touch it from HTTP goroutines,
and a racing write is a Go runtime fatal, not an error. The approver's
credential publication and the status poller's approved-branch snapshot
now run under the lock so the token can never be read half-written.
Regression test: TestApproveDeviceReapprovalRotatesToken — register →
approve → re-register same identifier → approve (must be 200) → token
rotated, exactly one devices row, row carries the new token.
John O'Keefe
1cd8557b58