FA-33426 / Menu interactions / Open access

Unresolved menu contribution anchor ignores the default slot · case 01

Unresolved menu contribution anchor ignores the default slot.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The contribution-anchors model applies `0` at its fallback-slot operation instead of the stipulated transformation.

VERIFIED REPAIR

Apply `p['slots'].get(p['requested'],p['slots']['default'])` at fallback-slot.

Unsuccessful approach: The attempted repair `p['slots'].get(p['requested'],len(p['slots']))` still violates the fallback-slot oracle.

Case contract

Menu contribution placement uses named before/after anchors and stable fallback slots; the before anchor owns precedence when both are supplied.

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 == 'before':
        return p['rows'][:p['rows'].index(p['anchor'])]+[p['id']]+p['rows'][p['rows'].index(p['anchor']):]
    if action == 'fallback-slot':
        return 0
    if action == 'anchor-owner':
        return (p['provider'],p['local'])
    if action == 'before-precedence':
        return p['before'] if p['before'] is not None else p['after']
    if action == 'batch-order':
        return p['rows'][:p['at']]+p['batch']+p['rows'][p['at']:]
    if action == 'self-anchor':
        return p['id']!=p['anchor']
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('before contract', solve('before', {'rows':['a','b'],'anchor':'b','id':N}), ['a',N,'b'])
check('fallback-slot contract', solve('fallback-slot', {'requested':'missing','slots':{'default':N+4,'start':0}}), N+4)
check('anchor-owner contract', solve('anchor-owner', {'provider':'p'+str(N),'local':'tools'}), ('p'+str(N),'tools'))
check('before-precedence contract', solve('before-precedence', {'before':N,'after':N+1}), N)
check('batch-order contract', solve('batch-order', {'rows':['a','b'],'at':1,'batch':[N,N+1]}), ['a',N,N+1,'b'])
check('self-anchor contract', solve('self-anchor', {'id':N,'anchor':N,'registered':[N]}), False)
check('unknown operation', solve('unknown', {}), {'error': 'unsupported menu operation'})
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
before contract	`['a', 1, 'b']`	`['a', 1, 'b']`	Passed
fallback-slot contract	`0`	`5`	Failed
anchor-owner contract	`['p1', 'tools']`	`['p1', 'tools']`	Passed
before-precedence contract	`1`	`1`	Passed
batch-order contract	`['a', 1, 2, 'b']`	`['a', 1, 2, 'b']`	Passed
self-anchor contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed

SHA-256 / 7595d1c080c31273ac87d4b97675f3d4d766e75aa69a6dee11229bee1eebc8b6

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 == 'before':
        return p['rows'][:p['rows'].index(p['anchor'])]+[p['id']]+p['rows'][p['rows'].index(p['anchor']):]
    if action == 'fallback-slot':
        return p['slots'].get(p['requested'],len(p['slots']))
    if action == 'anchor-owner':
        return (p['provider'],p['local'])
    if action == 'before-precedence':
        return p['before'] if p['before'] is not None else p['after']
    if action == 'batch-order':
        return p['rows'][:p['at']]+p['batch']+p['rows'][p['at']:]
    if action == 'self-anchor':
        return p['id']!=p['anchor']
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('before contract', solve('before', {'rows':['a','b'],'anchor':'b','id':N}), ['a',N,'b'])
check('fallback-slot contract', solve('fallback-slot', {'requested':'missing','slots':{'default':N+4,'start':0}}), N+4)
check('anchor-owner contract', solve('anchor-owner', {'provider':'p'+str(N),'local':'tools'}), ('p'+str(N),'tools'))
check('before-precedence contract', solve('before-precedence', {'before':N,'after':N+1}), N)
check('batch-order contract', solve('batch-order', {'rows':['a','b'],'at':1,'batch':[N,N+1]}), ['a',N,N+1,'b'])
check('self-anchor contract', solve('self-anchor', {'id':N,'anchor':N,'registered':[N]}), False)
check('unknown operation', solve('unknown', {}), {'error': 'unsupported menu operation'})
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
before contract	`['a', 1, 'b']`	`['a', 1, 'b']`	Passed
fallback-slot contract	`2`	`5`	Failed
anchor-owner contract	`['p1', 'tools']`	`['p1', 'tools']`	Passed
before-precedence contract	`1`	`1`	Passed
batch-order contract	`['a', 1, 2, 'b']`	`['a', 1, 2, 'b']`	Passed
self-anchor contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed

SHA-256 / 8fc44ef3f922230d1c12b92f2ed2ea9c0c9f15c68c451020b00850dd5671f4f9

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 == 'before':
        return p['rows'][:p['rows'].index(p['anchor'])]+[p['id']]+p['rows'][p['rows'].index(p['anchor']):]
    if action == 'fallback-slot':
        return p['slots'].get(p['requested'],p['slots']['default'])
    if action == 'anchor-owner':
        return (p['provider'],p['local'])
    if action == 'before-precedence':
        return p['before'] if p['before'] is not None else p['after']
    if action == 'batch-order':
        return p['rows'][:p['at']]+p['batch']+p['rows'][p['at']:]
    if action == 'self-anchor':
        return p['id']!=p['anchor']
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('before contract', solve('before', {'rows':['a','b'],'anchor':'b','id':N}), ['a',N,'b'])
check('fallback-slot contract', solve('fallback-slot', {'requested':'missing','slots':{'default':N+4,'start':0}}), N+4)
check('anchor-owner contract', solve('anchor-owner', {'provider':'p'+str(N),'local':'tools'}), ('p'+str(N),'tools'))
check('before-precedence contract', solve('before-precedence', {'before':N,'after':N+1}), N)
check('batch-order contract', solve('batch-order', {'rows':['a','b'],'at':1,'batch':[N,N+1]}), ['a',N,N+1,'b'])
check('self-anchor contract', solve('self-anchor', {'id':N,'anchor':N,'registered':[N]}), False)
check('unknown operation', solve('unknown', {}), {'error': 'unsupported menu operation'})
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
before contract	`['a', 1, 'b']`	`['a', 1, 'b']`	Passed
fallback-slot contract	`5`	`5`	Passed
anchor-owner contract	`['p1', 'tools']`	`['p1', 'tools']`	Passed
before-precedence contract	`1`	`1`	Passed
batch-order contract	`['a', 1, 2, 'b']`	`['a', 1, 2, 'b']`	Passed
self-anchor contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed

SHA-256 / 0614ffda1ef68fe8a39545107f5555f7a85446f2168eab25c02a22e423d50f89

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 2026-09-29T14:42:22.255164+00:00.

Case digest / 89bb0c77936f07ec29f6d0cc4223bc5ffb2a9b18dce16b76a1ed7618279c6fca