FA-33206 / Menu interactions / Open access

Concurrent menu subscribers start duplicate provider loads · case 01

Concurrent menu subscribers start duplicate provider loads.

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

ROOT CAUSE

The menu-provider-leases model applies `not p['loaded']` at its new-load operation instead of the stipulated transformation.

VERIFIED REPAIR

Apply `not p['loaded'] and not p['pending']` at new-load.

Unsuccessful approach: The attempted repair `not p['loaded'] or not p['pending']` still violates the new-load 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 not p['holders']
    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']
    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	`False`	`False`	Passed
visible-recipients contract	`[]`	`[]`	Passed
load-more contract	`False`	`False`	Passed
new-load contract	`True`	`False`	Failed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed
empty opaque cursor is valid	`True`	`True`	Passed

SHA-256 / ec3070542388b08391be93002cf6d0d493d72657fa73b7acbf3ab3bcd253a62f

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 not p['holders']
    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'] or 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	`False`	`False`	Passed
visible-recipients contract	`[]`	`[]`	Passed
load-more contract	`False`	`False`	Passed
new-load contract	`True`	`False`	Failed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed
empty opaque cursor is valid	`True`	`True`	Passed

SHA-256 / 977b2dbf65b3fc894b2d774b748aac16c8e22fc9b314ecaa75f718aee22996ab

3 / The verified repair

Exit 0

"""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 not p['holders']
    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	`False`	`False`	Passed
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 / 240bb7f27608ed88d3489ba59a84e602796817ee4fb98c005103f318844a3113

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 / d0fba922e128d2a74414f7ff67b79399919bcce7d845bf1152436af3486dfa72