FA-33016 / Menu interactions / Open access

Exactly fitting menu group is unnecessarily moved to overflow · case 01

Exactly fitting menu group is unnecessarily moved to overflow.

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

ROOT CAUSE

The overflow-menu model applies `p['groups']` at its group-atomic operation instead of the stipulated transformation.

THE FAILURE

The overflow-menu model applies `p['groups']` at its group-atomic operation instead of the stipulated transformation.

Unsuccessful approach: The attempted repair `[g for g in p['groups'] if g['width']<p['remaining']]` still violates the group-atomic oracle.

Case contract

A menu overflow container reserves its own trigger, preserves complete groups, and restores source order when room returns.

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 == 'reserve-trigger':
        return p['capacity']-p['trigger']
    if action == 'prefix-fit':
        return next((i for i in range(len(p['widths'])+1) if sum(p['widths'][:i+1])>p['capacity']),len(p['widths']))
    if action == 'suffix':
        return p['items'][p['fit']:]
    if action == 'group-atomic':
        return p['groups']
    if action == 'restore':
        return sorted(p,key=lambda x:x['source'])
    if action == 'trigger-visible':
        return bool(p['overflow'])
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('reserve-trigger contract', solve('reserve-trigger', {'capacity':N+10,'trigger':3}), N+7)
check('prefix-fit contract', solve('prefix-fit', {'widths':[N+1,N+1,N+1],'capacity':2*(N+1)}), 2)
check('suffix contract', solve('suffix', {'items':list(range(N+4)),'fit':2}), list(range(2,N+4)))
check('group-atomic contract', solve('group-atomic', {'groups':[{'width':N+2,'id':'a'},{'width':N+3,'id':'b'}],'remaining':N+2}), [{'width':N+2,'id':'a'}])
check('restore contract', solve('restore', [{'source':2,'label':'a'},{'source':N-N,'label':'z'}]), [{'source':0,'label':'z'},{'source':2,'label':'a'}])
check('trigger-visible contract', solve('trigger-visible', {'overflow':[],'capacity':N,'main':list(range(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
reserve-trigger contract	`8`	`8`	Passed
prefix-fit contract	`2`	`2`	Passed
suffix contract	`[2, 3, 4]`	`[2, 3, 4]`	Passed
group-atomic contract	`[{'id': 'a', 'width': 3}, {'id': 'b', 'width': 4}]`	`[{'id': 'a', 'width': 3}]`	Failed
restore contract	`[{'label': 'z', 'source': 0}, {'label': 'a', 'source': 2}]`	`[{'label': 'z', 'source': 0}, {'label': 'a', 'source': 2}]`	Passed
trigger-visible contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed

SHA-256 / a14c4d1bb24f825f0c06c787a8302c104c58b0be217e2a12aed3652580d8f2fb

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 == 'reserve-trigger':
        return p['capacity']-p['trigger']
    if action == 'prefix-fit':
        return next((i for i in range(len(p['widths'])+1) if sum(p['widths'][:i+1])>p['capacity']),len(p['widths']))
    if action == 'suffix':
        return p['items'][p['fit']:]
    if action == 'group-atomic':
        return [g for g in p['groups'] if g['width']<p['remaining']]
    if action == 'restore':
        return sorted(p,key=lambda x:x['source'])
    if action == 'trigger-visible':
        return bool(p['overflow'])
    return {'error': 'unsupported menu operation'}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('reserve-trigger contract', solve('reserve-trigger', {'capacity':N+10,'trigger':3}), N+7)
check('prefix-fit contract', solve('prefix-fit', {'widths':[N+1,N+1,N+1],'capacity':2*(N+1)}), 2)
check('suffix contract', solve('suffix', {'items':list(range(N+4)),'fit':2}), list(range(2,N+4)))
check('group-atomic contract', solve('group-atomic', {'groups':[{'width':N+2,'id':'a'},{'width':N+3,'id':'b'}],'remaining':N+2}), [{'width':N+2,'id':'a'}])
check('restore contract', solve('restore', [{'source':2,'label':'a'},{'source':N-N,'label':'z'}]), [{'source':0,'label':'z'},{'source':2,'label':'a'}])
check('trigger-visible contract', solve('trigger-visible', {'overflow':[],'capacity':N,'main':list(range(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
reserve-trigger contract	`8`	`8`	Passed
prefix-fit contract	`2`	`2`	Passed
suffix contract	`[2, 3, 4]`	`[2, 3, 4]`	Passed
group-atomic contract	`[]`	`[{'id': 'a', 'width': 3}]`	Failed
restore contract	`[{'label': 'z', 'source': 0}, {'label': 'a', 'source': 2}]`	`[{'label': 'z', 'source': 0}, {'label': 'a', 'source': 2}]`	Passed
trigger-visible contract	`False`	`False`	Passed
unknown operation	`{'error': 'unsupported menu operation'}`	`{'error': 'unsupported menu operation'}`	Passed

SHA-256 / 48797cb646caf73c17d8d162d6836dcf31cb26d1434b89b54d70b4fb76145cfb

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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 2026-09-29T14:42:18.187961+00:00.

Case digest / eb2131d38f362ef588aefc45db07527c9e8bac9bf9fe647027619fedbae4cab0