FA-33191 / Menu interactions / Open access

Single remaining menu subscriber loses its shared provider · case 01

Single remaining menu subscriber loses its shared provider.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The menu-provider-leases model applies `True` at its dispose operation instead of the stipulated transformation.

THE FAILURE

The menu-provider-leases model applies `True` at its dispose operation instead of the stipulated transformation.

Unsuccessful approach: The attempted repair `len(p['holders'])<=1` still violates the dispose oracle.

Case contract

Providers can be shared by multiple menu surfaces; leases control attachment lifetime and only visible subscribers receive presentation updates.

Why this case matters

Cascading and context menus require coherent command and session state as content changes.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
import unicodedata
N = 1
observations = []
def solve(action, p):
    if action == 'acquire':
        return sorted(p['holders'] | {p['id']})
    if action == 'release':
        return sorted(p['holders']-{p['id']})
    if action == 'dispose':
        return True
    if action == 'visible-recipients':
        return [x['id'] for x in p if x['visible'] and x['attached']]
    if action == 'load-more':
        return p['next'] is not None and not p['pending_page']
    if action == 'new-load':
        return not p['loaded'] and not p['pending']
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('acquire contract', solve('acquire', {'holders':{'a'},'id':'b'+str(N)}), ['a','b'+str(N)])
check('release contract', solve('release', {'holders':{'a','b'+str(N)},'id':'a'}), ['b'+str(N)])
check('dispose contract', solve('dispose', {'holders':['menu'+str(N)]}), False)
check('visible-recipients contract', solve('visible-recipients', [{'id':N,'visible':False,'attached':True},{'id':N+1,'visible':True,'attached':False}]), [])
check('load-more contract', solve('load-more', {'next':'cursor'+str(N),'pending_page':True}), False)
check('new-load contract', solve('new-load', {'loaded':False,'pending':True,'leases':N}), False)
check('unknown operation', solve('unknown', {}), {'error': 'unsupported menu operation'})
check('empty opaque cursor is valid',solve('load-more',{'next':'','pending_page':False,'generation':N}),True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
acquire contract	`['a', 'b1']`	`['a', 'b1']`	Passed
release contract	`['b1']`	`['b1']`	Passed
dispose contract	`True`	`False`	Failed
visible-recipients contract	`[]`	`[]`	Passed
load-more contract	`False`	`False`	Passed
new-load contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed
empty opaque cursor is valid	`True`	`True`	Passed

SHA-256 / bb4d5ceec59abb58d29417114c32351b730561346a136bacb1d592aa2b4dc14e

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
import unicodedata
N = 1
observations = []
def solve(action, p):
    if action == 'acquire':
        return sorted(p['holders'] | {p['id']})
    if action == 'release':
        return sorted(p['holders']-{p['id']})
    if action == 'dispose':
        return len(p['holders'])<=1
    if action == 'visible-recipients':
        return [x['id'] for x in p if x['visible'] and x['attached']]
    if action == 'load-more':
        return p['next'] is not None and not p['pending_page']
    if action == 'new-load':
        return not p['loaded'] and not p['pending']
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('acquire contract', solve('acquire', {'holders':{'a'},'id':'b'+str(N)}), ['a','b'+str(N)])
check('release contract', solve('release', {'holders':{'a','b'+str(N)},'id':'a'}), ['b'+str(N)])
check('dispose contract', solve('dispose', {'holders':['menu'+str(N)]}), False)
check('visible-recipients contract', solve('visible-recipients', [{'id':N,'visible':False,'attached':True},{'id':N+1,'visible':True,'attached':False}]), [])
check('load-more contract', solve('load-more', {'next':'cursor'+str(N),'pending_page':True}), False)
check('new-load contract', solve('new-load', {'loaded':False,'pending':True,'leases':N}), False)
check('unknown operation', solve('unknown', {}), {'error': 'unsupported menu operation'})
check('empty opaque cursor is valid',solve('load-more',{'next':'','pending_page':False,'generation':N}),True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
acquire contract	`['a', 'b1']`	`['a', 'b1']`	Passed
release contract	`['b1']`	`['b1']`	Passed
dispose contract	`True`	`False`	Failed
visible-recipients contract	`[]`	`[]`	Passed
load-more contract	`False`	`False`	Passed
new-load contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed
empty opaque cursor is valid	`True`	`True`	Passed

SHA-256 / 92af2a6e4d276099efc1f384b7748da96311fa201bda70184e331338f5540386

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Offline supplied-valid-payload model; excludes DOM, keyboard, focus, selection, announcements and browser conformance. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:42:19.975256+00:00.

Case digest / 25bce232fec10d544eb27a6088b752d2cd975b66b152aa356b421d9c04df8811