The plan's cachedPermissionStore used scopeKey + U+FFFD + subjectId as a
cache key with no escaping, so ('a', 'b<sep>c') and ('a<sep>b', 'c') collide
and one subject is served another's permissions. Subject and tenant ids are
unconstrained strings, so nothing prevented it.
Key is now JSON-encoded, and the global-write sweep tracks keys per subject
instead of substring-matching. Adds the two regression tests that were
missing: cross-tenant invalidation on a global write, and key collision.
Ruled by the human as plan-mandated; source of truth amended so a re-run of
the plan does not reintroduce the defect.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
ClintchizandClaude Opus 5
83f2951035
