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Rolling back an inner savepoint erases its parent observer changes · case 02

Rolling back an inner savepoint erases its parent observer changes; the returned lifecycle plan violates the stated transition contract.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Plan observer notifications around a local state transaction. Pending changes become visible only after successful outermost commit. Rollback restores the prior published revision. Change records [field,old,new] with equal endpoints are suppressed; repeated fields keep the earliest old and latest new in input order. Observer errors do not roll back an already committed state. An inner savepoint contributes child changes only on commit without rollback; parent changes survive every child outcome. Committed observer failures are [registration_position,error] records and report in stable registration order, retaining arrival order for a tied position. Inputs are finite state snapshots, including transitional and stale states; output fields are the exact independent actions/metadata defined by the corrected expression table. Numeric fixture capacities and counts vary with N. Field definitions, each independently computed from the input snapshot: visible = s['committed'] and not s['rollback'] and s['depth']==0; changed = [r for r in s['changes'] if r[1]!=r[2]]; first_old = {k:next(r[1] for r in s['changes'] if r[0]==k) for k in dict.fromkeys(r[0] for r in s['changes'])}; last_new = {r[0]:r[2] for r in s['changes']}; order = list(dict.fromkeys(r[0] for r in s['changes'])); revision = s['published'] if s['rollback'] else s['revision']; state_rollback = s['rollback'] and not s['committed']; notify_error = sorted(s['observer_failures'],key=lambda r:r[0]); publish_durable = s['committed'] and s['durable'] and not s['rollback']; deferred = list(s['parent_changes'])+(list(s['child_changes']) if s['child_commit'] and not s['child_rollback'] else [])

Why this case matters

Observer implementations need to preserve this state while subscriptions enter, execute, and leave their lifecycle.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
transition 0	`{"changed": [["x", 1, 4], ["x", 4, 6]], "deferred": ["parent", "child"], "first_old": {"x": 1, "y": 8}, "last_new": {"x": 6, "y": 8}, "notify_error": [[0, "z"], [1, "m"], [4, "a"]], "order": ["x", "y"], "publish_durable": false, "revision": 4, "state_rollback": false, "visible": false}`	`{"changed": [["x", 1, 4], ["x", 4, 6]], "deferred": ["parent"], "first_old": {"x": 1, "y": 8}, "last_new": {"x": 6, "y": 8}, "notify_error": [[0, "z"], [1, "m"], [4, "a"]], "order": ["x", "y"], "publish_durable": false, "revision": 4, "state_rollback": false, "visible": false}`	Failed

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