FAILURE MAP
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FA-23746 / Client state / Open access

Per-history-entry scroll restoration: Anchor precedes saved position · case 01

Anchor precedes saved position.

Verified by executionVariant 1 · 60 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The anchor-precedes-saved-position client decision evaluates `positions.get(entry,0)` instead of `anchor if anchor is not None else positions.get(entry,0)`.

THE FAILURE

The anchor-precedes-saved-position client decision evaluates `positions.get(entry,0)` instead of `anchor if anchor is not None else positions.get(entry,0)`.

Unsuccessful approach: The partial repair `anchor or positions.get(entry,0)` still violates the explicit fixture contract.

Case contract

Scroll state belongs to a history entry, not its repeated URL. Pop restores after layout, pushes start at top, explicit anchors including the empty anchor take precedence, and positions clamp to the scrollable extent. Operation anchor-precedes-saved-position has the six explicit input/output oracles below.

Why this case matters

An offline client lifecycle model that isolates a state-management defect without DOM rendering or network services.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(operation, s):
    positions, entry, path, event, ready, anchor, height, viewport = s
    if operation == 'entry-key-lookup':
        return positions.get(entry,0)
    if operation == 'push-resets-position':
        return positions.get(entry,0) if event=='pop' else 0
    if operation == 'layout-ready-deferral':
        return positions.get(entry,0) if ready else None
    if operation == 'clamp-restored-position':
        return min(max(0,positions.get(entry,0)),max(0,height-viewport))
    if operation == 'anchor-precedes-saved-position':
        return positions.get(entry,0)
    if operation == 'missing-entry-detection':
        return entry not in positions
    if operation == 'restoration-mode':
        return 'manual' if event=='pop' else 'auto'
    if operation == 'saved-position-prune':
        return {k:v for k,v in positions.items() if k!=entry}
    if operation == 'anchor-layout-gate':
        return anchor if ready and anchor is not None else None
    if operation == 'restore-command':
        return 'wait' if not ready else ('anchor' if anchor is not None else ('saved' if event=='pop' else 'top'))
    raise ValueError('unknown modeled operation')
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('entry-key-lookup scenario 1', solve('entry-key-lookup', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('entry-key-lookup scenario 2', solve('entry-key-lookup', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('entry-key-lookup scenario 3', solve('entry-key-lookup', ({},'e2','/a','pop',True,None,10,20)), 0)
check('entry-key-lookup scenario 4', solve('entry-key-lookup', ({'e1':90},'e1','/a','pop',False,None,100,20)), 90)
check('entry-key-lookup scenario 5', solve('entry-key-lookup', ({'e1':-5},'e1','/b','replace',True,'',100,20)), -5)
check('entry-key-lookup scenario 6', solve('entry-key-lookup', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('push-resets-position scenario 1', solve('push-resets-position', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('push-resets-position scenario 2', solve('push-resets-position', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('push-resets-position scenario 3', solve('push-resets-position', ({},'e2','/a','pop',True,None,10,20)), 0)
check('push-resets-position scenario 4', solve('push-resets-position', ({'e1':90},'e1','/a','pop',False,None,100,20)), 90)
check('push-resets-position scenario 5', solve('push-resets-position', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 0)
check('push-resets-position scenario 6', solve('push-resets-position', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('layout-ready-deferral scenario 1', solve('layout-ready-deferral', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('layout-ready-deferral scenario 2', solve('layout-ready-deferral', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('layout-ready-deferral scenario 3', solve('layout-ready-deferral', ({},'e2','/a','pop',True,None,10,20)), 0)
check('layout-ready-deferral scenario 4', solve('layout-ready-deferral', ({'e1':90},'e1','/a','pop',False,None,100,20)), None)
check('layout-ready-deferral scenario 5', solve('layout-ready-deferral', ({'e1':-5},'e1','/b','replace',True,'',100,20)), -5)
check('layout-ready-deferral scenario 6', solve('layout-ready-deferral', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('clamp-restored-position scenario 1', solve('clamp-restored-position', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('clamp-restored-position scenario 2', solve('clamp-restored-position', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('clamp-restored-position scenario 3', solve('clamp-restored-position', ({},'e2','/a','pop',True,None,10,20)), 0)
check('clamp-restored-position scenario 4', solve('clamp-restored-position', ({'e1':90},'e1','/a','pop',False,None,100,20)), 80)
check('clamp-restored-position scenario 5', solve('clamp-restored-position', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 0)
check('clamp-restored-position scenario 6', solve('clamp-restored-position', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('anchor-precedes-saved-position scenario 1', solve('anchor-precedes-saved-position', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('anchor-precedes-saved-position scenario 2', solve('anchor-precedes-saved-position', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'section')
check('anchor-precedes-saved-position scenario 3', solve('anchor-precedes-saved-position', ({},'e2','/a','pop',True,None,10,20)), 0)
check('anchor-precedes-saved-position scenario 4', solve('anchor-precedes-saved-position', ({'e1':90},'e1','/a','pop',False,None,100,20)), 90)
check('anchor-precedes-saved-position scenario 5', solve('anchor-precedes-saved-position', ({'e1':-5},'e1','/b','replace',True,'',100,20)), '')
check('anchor-precedes-saved-position scenario 6', solve('anchor-precedes-saved-position', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'section')
check('missing-entry-detection scenario 1', solve('missing-entry-detection', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), False)
check('missing-entry-detection scenario 2', solve('missing-entry-detection', ({'e1':0},'e1','/a','push',True,'section',100,20)), False)
check('missing-entry-detection scenario 3', solve('missing-entry-detection', ({},'e2','/a','pop',True,None,10,20)), True)
check('missing-entry-detection scenario 4', solve('missing-entry-detection', ({'e1':90},'e1','/a','pop',False,None,100,20)), False)
check('missing-entry-detection scenario 5', solve('missing-entry-detection', ({'e1':-5},'e1','/b','replace',True,'',100,20)), False)
check('missing-entry-detection scenario 6', solve('missing-entry-detection', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), False)
check('restoration-mode scenario 1', solve('restoration-mode', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), 'manual')
check('restoration-mode scenario 2', solve('restoration-mode', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'auto')
check('restoration-mode scenario 3', solve('restoration-mode', ({},'e2','/a','pop',True,None,10,20)), 'manual')
check('restoration-mode scenario 4', solve('restoration-mode', ({'e1':90},'e1','/a','pop',False,None,100,20)), 'manual')
check('restoration-mode scenario 5', solve('restoration-mode', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 'auto')
check('restoration-mode scenario 6', solve('restoration-mode', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'manual')
check('saved-position-prune scenario 1', solve('saved-position-prune', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), {'e2':50})
check('saved-position-prune scenario 2', solve('saved-position-prune', ({'e1':0},'e1','/a','push',True,'section',100,20)), {})
check('saved-position-prune scenario 3', solve('saved-position-prune', ({},'e2','/a','pop',True,None,10,20)), {})
check('saved-position-prune scenario 4', solve('saved-position-prune', ({'e1':90},'e1','/a','pop',False,None,100,20)), {})
check('saved-position-prune scenario 5', solve('saved-position-prune', ({'e1':-5},'e1','/b','replace',True,'',100,20)), {})
check('saved-position-prune scenario 6', solve('saved-position-prune', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), {'/a':70})
check('anchor-layout-gate scenario 1', solve('anchor-layout-gate', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), None)
check('anchor-layout-gate scenario 2', solve('anchor-layout-gate', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'section')
check('anchor-layout-gate scenario 3', solve('anchor-layout-gate', ({},'e2','/a','pop',True,None,10,20)), None)
check('anchor-layout-gate scenario 4', solve('anchor-layout-gate', ({'e1':90},'e1','/a','pop',False,None,100,20)), None)
check('anchor-layout-gate scenario 5', solve('anchor-layout-gate', ({'e1':-5},'e1','/b','replace',True,'',100,20)), '')
check('anchor-layout-gate scenario 6', solve('anchor-layout-gate', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'section')
check('restore-command scenario 1', solve('restore-command', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), 'saved')
check('restore-command scenario 2', solve('restore-command', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'anchor')
check('restore-command scenario 3', solve('restore-command', ({},'e2','/a','pop',True,None,10,20)), 'saved')
check('restore-command scenario 4', solve('restore-command', ({'e1':90},'e1','/a','pop',False,None,100,20)), 'wait')
check('restore-command scenario 5', solve('restore-command', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 'anchor')
check('restore-command scenario 6', solve('restore-command', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'anchor')
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 fixtureActualExpectedOutcome
entry-key-lookup scenario 11010Passed
entry-key-lookup scenario 200Passed
entry-key-lookup scenario 300Passed
entry-key-lookup scenario 49090Passed
entry-key-lookup scenario 5-5-5Passed
entry-key-lookup scenario 61515Passed
push-resets-position scenario 11010Passed
push-resets-position scenario 200Passed
push-resets-position scenario 300Passed
push-resets-position scenario 49090Passed
push-resets-position scenario 500Passed
push-resets-position scenario 61515Passed
layout-ready-deferral scenario 11010Passed
layout-ready-deferral scenario 200Passed
layout-ready-deferral scenario 300Passed
layout-ready-deferral scenario 4NoneNonePassed
layout-ready-deferral scenario 5-5-5Passed
layout-ready-deferral scenario 61515Passed
clamp-restored-position scenario 11010Passed
clamp-restored-position scenario 200Passed
clamp-restored-position scenario 300Passed
clamp-restored-position scenario 48080Passed
clamp-restored-position scenario 500Passed
clamp-restored-position scenario 61515Passed
anchor-precedes-saved-position scenario 11010Passed
anchor-precedes-saved-position scenario 20sectionFailed
anchor-precedes-saved-position scenario 300Passed
anchor-precedes-saved-position scenario 49090Passed
anchor-precedes-saved-position scenario 5-5Failed
anchor-precedes-saved-position scenario 615sectionFailed
missing-entry-detection scenario 1FalseFalsePassed
missing-entry-detection scenario 2FalseFalsePassed
missing-entry-detection scenario 3TrueTruePassed
missing-entry-detection scenario 4FalseFalsePassed
missing-entry-detection scenario 5FalseFalsePassed
missing-entry-detection scenario 6FalseFalsePassed
restoration-mode scenario 1manualmanualPassed
restoration-mode scenario 2autoautoPassed
restoration-mode scenario 3manualmanualPassed
restoration-mode scenario 4manualmanualPassed
restoration-mode scenario 5autoautoPassed
restoration-mode scenario 6manualmanualPassed
saved-position-prune scenario 1{'e2': 50}{'e2': 50}Passed
saved-position-prune scenario 2{}{}Passed
saved-position-prune scenario 3{}{}Passed
saved-position-prune scenario 4{}{}Passed
saved-position-prune scenario 5{}{}Passed
saved-position-prune scenario 6{'/a': 70}{'/a': 70}Passed
anchor-layout-gate scenario 1NoneNonePassed
anchor-layout-gate scenario 2sectionsectionPassed
anchor-layout-gate scenario 3NoneNonePassed
anchor-layout-gate scenario 4NoneNonePassed
anchor-layout-gate scenario 5Passed
anchor-layout-gate scenario 6sectionsectionPassed
restore-command scenario 1savedsavedPassed
restore-command scenario 2anchoranchorPassed
restore-command scenario 3savedsavedPassed
restore-command scenario 4waitwaitPassed
restore-command scenario 5anchoranchorPassed
restore-command scenario 6anchoranchorPassed

SHA-256 / 73c0b05d83deaaf4ce9f4207472d881bbe652adff4c99559dc03ee126f7bef78

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(operation, s):
    positions, entry, path, event, ready, anchor, height, viewport = s
    if operation == 'entry-key-lookup':
        return positions.get(entry,0)
    if operation == 'push-resets-position':
        return positions.get(entry,0) if event=='pop' else 0
    if operation == 'layout-ready-deferral':
        return positions.get(entry,0) if ready else None
    if operation == 'clamp-restored-position':
        return min(max(0,positions.get(entry,0)),max(0,height-viewport))
    if operation == 'anchor-precedes-saved-position':
        return anchor or positions.get(entry,0)
    if operation == 'missing-entry-detection':
        return entry not in positions
    if operation == 'restoration-mode':
        return 'manual' if event=='pop' else 'auto'
    if operation == 'saved-position-prune':
        return {k:v for k,v in positions.items() if k!=entry}
    if operation == 'anchor-layout-gate':
        return anchor if ready and anchor is not None else None
    if operation == 'restore-command':
        return 'wait' if not ready else ('anchor' if anchor is not None else ('saved' if event=='pop' else 'top'))
    raise ValueError('unknown modeled operation')
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('entry-key-lookup scenario 1', solve('entry-key-lookup', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('entry-key-lookup scenario 2', solve('entry-key-lookup', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('entry-key-lookup scenario 3', solve('entry-key-lookup', ({},'e2','/a','pop',True,None,10,20)), 0)
check('entry-key-lookup scenario 4', solve('entry-key-lookup', ({'e1':90},'e1','/a','pop',False,None,100,20)), 90)
check('entry-key-lookup scenario 5', solve('entry-key-lookup', ({'e1':-5},'e1','/b','replace',True,'',100,20)), -5)
check('entry-key-lookup scenario 6', solve('entry-key-lookup', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('push-resets-position scenario 1', solve('push-resets-position', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('push-resets-position scenario 2', solve('push-resets-position', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('push-resets-position scenario 3', solve('push-resets-position', ({},'e2','/a','pop',True,None,10,20)), 0)
check('push-resets-position scenario 4', solve('push-resets-position', ({'e1':90},'e1','/a','pop',False,None,100,20)), 90)
check('push-resets-position scenario 5', solve('push-resets-position', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 0)
check('push-resets-position scenario 6', solve('push-resets-position', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('layout-ready-deferral scenario 1', solve('layout-ready-deferral', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('layout-ready-deferral scenario 2', solve('layout-ready-deferral', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('layout-ready-deferral scenario 3', solve('layout-ready-deferral', ({},'e2','/a','pop',True,None,10,20)), 0)
check('layout-ready-deferral scenario 4', solve('layout-ready-deferral', ({'e1':90},'e1','/a','pop',False,None,100,20)), None)
check('layout-ready-deferral scenario 5', solve('layout-ready-deferral', ({'e1':-5},'e1','/b','replace',True,'',100,20)), -5)
check('layout-ready-deferral scenario 6', solve('layout-ready-deferral', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('clamp-restored-position scenario 1', solve('clamp-restored-position', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('clamp-restored-position scenario 2', solve('clamp-restored-position', ({'e1':0},'e1','/a','push',True,'section',100,20)), 0)
check('clamp-restored-position scenario 3', solve('clamp-restored-position', ({},'e2','/a','pop',True,None,10,20)), 0)
check('clamp-restored-position scenario 4', solve('clamp-restored-position', ({'e1':90},'e1','/a','pop',False,None,100,20)), 80)
check('clamp-restored-position scenario 5', solve('clamp-restored-position', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 0)
check('clamp-restored-position scenario 6', solve('clamp-restored-position', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 15)
check('anchor-precedes-saved-position scenario 1', solve('anchor-precedes-saved-position', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), N*10)
check('anchor-precedes-saved-position scenario 2', solve('anchor-precedes-saved-position', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'section')
check('anchor-precedes-saved-position scenario 3', solve('anchor-precedes-saved-position', ({},'e2','/a','pop',True,None,10,20)), 0)
check('anchor-precedes-saved-position scenario 4', solve('anchor-precedes-saved-position', ({'e1':90},'e1','/a','pop',False,None,100,20)), 90)
check('anchor-precedes-saved-position scenario 5', solve('anchor-precedes-saved-position', ({'e1':-5},'e1','/b','replace',True,'',100,20)), '')
check('anchor-precedes-saved-position scenario 6', solve('anchor-precedes-saved-position', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'section')
check('missing-entry-detection scenario 1', solve('missing-entry-detection', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), False)
check('missing-entry-detection scenario 2', solve('missing-entry-detection', ({'e1':0},'e1','/a','push',True,'section',100,20)), False)
check('missing-entry-detection scenario 3', solve('missing-entry-detection', ({},'e2','/a','pop',True,None,10,20)), True)
check('missing-entry-detection scenario 4', solve('missing-entry-detection', ({'e1':90},'e1','/a','pop',False,None,100,20)), False)
check('missing-entry-detection scenario 5', solve('missing-entry-detection', ({'e1':-5},'e1','/b','replace',True,'',100,20)), False)
check('missing-entry-detection scenario 6', solve('missing-entry-detection', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), False)
check('restoration-mode scenario 1', solve('restoration-mode', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), 'manual')
check('restoration-mode scenario 2', solve('restoration-mode', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'auto')
check('restoration-mode scenario 3', solve('restoration-mode', ({},'e2','/a','pop',True,None,10,20)), 'manual')
check('restoration-mode scenario 4', solve('restoration-mode', ({'e1':90},'e1','/a','pop',False,None,100,20)), 'manual')
check('restoration-mode scenario 5', solve('restoration-mode', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 'auto')
check('restoration-mode scenario 6', solve('restoration-mode', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'manual')
check('saved-position-prune scenario 1', solve('saved-position-prune', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), {'e2':50})
check('saved-position-prune scenario 2', solve('saved-position-prune', ({'e1':0},'e1','/a','push',True,'section',100,20)), {})
check('saved-position-prune scenario 3', solve('saved-position-prune', ({},'e2','/a','pop',True,None,10,20)), {})
check('saved-position-prune scenario 4', solve('saved-position-prune', ({'e1':90},'e1','/a','pop',False,None,100,20)), {})
check('saved-position-prune scenario 5', solve('saved-position-prune', ({'e1':-5},'e1','/b','replace',True,'',100,20)), {})
check('saved-position-prune scenario 6', solve('saved-position-prune', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), {'/a':70})
check('anchor-layout-gate scenario 1', solve('anchor-layout-gate', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), None)
check('anchor-layout-gate scenario 2', solve('anchor-layout-gate', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'section')
check('anchor-layout-gate scenario 3', solve('anchor-layout-gate', ({},'e2','/a','pop',True,None,10,20)), None)
check('anchor-layout-gate scenario 4', solve('anchor-layout-gate', ({'e1':90},'e1','/a','pop',False,None,100,20)), None)
check('anchor-layout-gate scenario 5', solve('anchor-layout-gate', ({'e1':-5},'e1','/b','replace',True,'',100,20)), '')
check('anchor-layout-gate scenario 6', solve('anchor-layout-gate', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'section')
check('restore-command scenario 1', solve('restore-command', ({'e1':N*10,'e2':50},'e1','/a','pop',True,None,100,20)), 'saved')
check('restore-command scenario 2', solve('restore-command', ({'e1':0},'e1','/a','push',True,'section',100,20)), 'anchor')
check('restore-command scenario 3', solve('restore-command', ({},'e2','/a','pop',True,None,10,20)), 'saved')
check('restore-command scenario 4', solve('restore-command', ({'e1':90},'e1','/a','pop',False,None,100,20)), 'wait')
check('restore-command scenario 5', solve('restore-command', ({'e1':-5},'e1','/b','replace',True,'',100,20)), 'anchor')
check('restore-command scenario 6', solve('restore-command', ({'/a':70,'e1':15},'e1','/a','pop',True,'section',40,20)), 'anchor')
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 fixtureActualExpectedOutcome
entry-key-lookup scenario 11010Passed
entry-key-lookup scenario 200Passed
entry-key-lookup scenario 300Passed
entry-key-lookup scenario 49090Passed
entry-key-lookup scenario 5-5-5Passed
entry-key-lookup scenario 61515Passed
push-resets-position scenario 11010Passed
push-resets-position scenario 200Passed
push-resets-position scenario 300Passed
push-resets-position scenario 49090Passed
push-resets-position scenario 500Passed
push-resets-position scenario 61515Passed
layout-ready-deferral scenario 11010Passed
layout-ready-deferral scenario 200Passed
layout-ready-deferral scenario 300Passed
layout-ready-deferral scenario 4NoneNonePassed
layout-ready-deferral scenario 5-5-5Passed
layout-ready-deferral scenario 61515Passed
clamp-restored-position scenario 11010Passed
clamp-restored-position scenario 200Passed
clamp-restored-position scenario 300Passed
clamp-restored-position scenario 48080Passed
clamp-restored-position scenario 500Passed
clamp-restored-position scenario 61515Passed
anchor-precedes-saved-position scenario 11010Passed
anchor-precedes-saved-position scenario 2sectionsectionPassed
anchor-precedes-saved-position scenario 300Passed
anchor-precedes-saved-position scenario 49090Passed
anchor-precedes-saved-position scenario 5-5Failed
anchor-precedes-saved-position scenario 6sectionsectionPassed
missing-entry-detection scenario 1FalseFalsePassed
missing-entry-detection scenario 2FalseFalsePassed
missing-entry-detection scenario 3TrueTruePassed
missing-entry-detection scenario 4FalseFalsePassed
missing-entry-detection scenario 5FalseFalsePassed
missing-entry-detection scenario 6FalseFalsePassed
restoration-mode scenario 1manualmanualPassed
restoration-mode scenario 2autoautoPassed
restoration-mode scenario 3manualmanualPassed
restoration-mode scenario 4manualmanualPassed
restoration-mode scenario 5autoautoPassed
restoration-mode scenario 6manualmanualPassed
saved-position-prune scenario 1{'e2': 50}{'e2': 50}Passed
saved-position-prune scenario 2{}{}Passed
saved-position-prune scenario 3{}{}Passed
saved-position-prune scenario 4{}{}Passed
saved-position-prune scenario 5{}{}Passed
saved-position-prune scenario 6{'/a': 70}{'/a': 70}Passed
anchor-layout-gate scenario 1NoneNonePassed
anchor-layout-gate scenario 2sectionsectionPassed
anchor-layout-gate scenario 3NoneNonePassed
anchor-layout-gate scenario 4NoneNonePassed
anchor-layout-gate scenario 5Passed
anchor-layout-gate scenario 6sectionsectionPassed
restore-command scenario 1savedsavedPassed
restore-command scenario 2anchoranchorPassed
restore-command scenario 3savedsavedPassed
restore-command scenario 4waitwaitPassed
restore-command scenario 5anchoranchorPassed
restore-command scenario 6anchoranchorPassed

SHA-256 / adae6bcf375d5e9e45e5e89d2d7345e5ee9770b35f82b49366023bd0ef0f5cf4

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 60 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.

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Verification & scope

Only the explicitly specified operations and finite deterministic records are modeled; no browser or framework conformance is claimed. 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 2026-09-29T14:40:50.921407+00:00.

Case digest / fec20ec5a9721040d8fc74dc43658cc6e9aa5cc6a1ec1496332bc80b0298cdb7