Reported from the running app: a message showed as unread in the list — bold,
blue dot — while the reading pane showed it as read, and only a manual "mark as
read" reconciled them.
The two views read different things. The pane reads the message's own flags; the
list reads `threads.unread_count`, denormalized from them. `apply_delta` updated
message flags with a bare UPDATE and never recomputed the thread, so a flag set
anywhere but in this app — read on a phone, filed by a server-side rule — moved
one and not the other. Auto-mark-on-read could not fix it either: it sees a
message that is already \Seen and correctly does nothing, leaving the counter
wrong forever.
Expunges had the same hole, which also left `message_count` overstated.
`apply_delta` now collects the affected threads and re-denormalizes them after
the deletes, so a thread emptied by an expunge is removed rather than recounted.
Migration 0018 repairs rows that already drifted — recomputed from the messages,
so it is a no-op on a healthy database. One thread was stale here; installs that
have been syncing longer will have more.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018SqJYt7jD7oUEkoY68sBZo
lukasandClaude Opus 5
e58a2f0ef4