A reaction toggled twice at once is a no-op, not a 500

Shipped

27 ஆகஸ்ட், 2026 அன்று 1:59 AM UTC

Author

kamo

Commit

3b3284f

setReaction read, then saved, then caught the constraint violation the read was supposed to prevent — which does not work: the violation surfaces at flush, after the catch, on a transaction that is already rollback-only. Two devices reacting with the same emoji at the same instant would have answered 500 and rolled the reaction back. It now goes through the shared library's ON CONFLICT DO NOTHING upsert, so the second write is a no-op and both callers get the state they asked for.