FA-39071 / Tree accessibility / Open access

Hierarchical clipboard root normalization: Old cut generation remains move-capable · case 01

Old cut generation remains move-capable produces the wrong hierarchical widget state in a regression fixture.

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

ROOT CAUSE

The subtree-clipboard contract is violated at `d['clipboard_generation']==d['generation']` by replacing it with `True`.

THE FAILURE

The subtree-clipboard contract is violated at `d['clipboard_generation']==d['generation']` by replacing it with `True`.

Unsuccessful approach: The partial repair `False` still violates a boundary or preservation case.

Case contract

Copy or cut operates on selected topmost roots only, excluding descendants of a selected root. Roots follow tree order. Cut excludes read-only roots, retains protected selection, and advertises a move only within the same tree generation. Clipboard payload carries selected root paths and descendants once.

Why this case matters

Offline executable model of a hierarchical accessibility interaction; inputs are bounded and valid as stipulated. No browser, assistive technology, or normative ARIA conformance is claimed.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(d):
    selected=set(d['selected'])&set(d['rows'])
    roots=[x for x in d['rows'] if x in selected and not any(a in selected for a in d['ancestors'].get(x,[]))]
    allowed=[x for x in roots if d['mode']=='copy' or x not in d['readonly']]
    closure=[x for x in d['rows'] if x in allowed or any(a in allowed for a in d['ancestors'].get(x,[]))]
    paths={x:d['ancestors'].get(x,[])+[x] for x in allowed}
    cut=allowed if d['mode']=='cut' else []
    valid=True
    effect='move' if cut and valid and d['same_tree'] else ('copy' if allowed else 'none')
    remaining=[x for x in d['selected'] if x not in closure] if effect=='move' else d['selected']
    focus=allowed[0] if allowed else d['focus']
    return [allowed,closure,paths,cut,effect,remaining,focus]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 0, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 2: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 3: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 4: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 5: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])]}
for label, data, expected in cases[N]:
    check(label, solve(data), expected)
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
cut normalized	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']`	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']`	Passed
copy protected	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']`	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']`	Passed
several roots	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']`	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']`	Passed
stale cut	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']`	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	Failed
cross tree	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	Passed
no selection	`[[], [], {}, [], 'none', [], 'c']`	`[[], [], {}, [], 'none', [], 'c']`	Passed
descendant alone	`[['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b']`	`[['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b']`	Passed

SHA-256 / a2c953afb4276e24199eaa4d100fb5dc7b9cd798df54470df585626234125351

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(d):
    selected=set(d['selected'])&set(d['rows'])
    roots=[x for x in d['rows'] if x in selected and not any(a in selected for a in d['ancestors'].get(x,[]))]
    allowed=[x for x in roots if d['mode']=='copy' or x not in d['readonly']]
    closure=[x for x in d['rows'] if x in allowed or any(a in allowed for a in d['ancestors'].get(x,[]))]
    paths={x:d['ancestors'].get(x,[])+[x] for x in allowed}
    cut=allowed if d['mode']=='cut' else []
    valid=False
    effect='move' if cut and valid and d['same_tree'] else ('copy' if allowed else 'none')
    remaining=[x for x in d['selected'] if x not in closure] if effect=='move' else d['selected']
    focus=allowed[0] if allowed else d['focus']
    return [allowed,closure,paths,cut,effect,remaining,focus]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 0, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 1, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 2: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 1, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 2, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 3: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 2, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 3, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 4: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 3, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 4, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])], 5: [('cut normalized', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']), ('copy protected', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'copy', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']), ('several roots', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': [], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']), ('stale cut', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 4, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('cross tree', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['a', 'b', 'q'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': False, 'focus': 'c'}, [['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']), ('no selection', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': [], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [[], [], {}, [], 'none', [], 'c']), ('descendant alone', {'rows': ['z', 'a', 'b', 'c', 'q', 'v0', 'v1', 'v2', 'v3', 'v4'], 'selected': ['b'], 'ancestors': {'a': ['z'], 'b': ['z', 'a'], 'c': ['z', 'a', 'b']}, 'mode': 'cut', 'readonly': ['q'], 'clipboard_generation': 5, 'generation': 5, 'same_tree': True, 'focus': 'c'}, [['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b'])]}
for label, data, expected in cases[N]:
    check(label, solve(data), expected)
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
cut normalized	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'move', ['q'], 'a']`	Failed
copy protected	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']`	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, [], 'copy', ['a', 'b', 'q'], 'a']`	Passed
several roots	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'copy', ['a', 'b', 'q'], 'a']`	`[['a', 'q'], ['a', 'b', 'c', 'q'], {'a': ['z', 'a'], 'q': ['q']}, ['a', 'q'], 'move', [], 'a']`	Failed
stale cut	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	Passed
cross tree	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	`[['a'], ['a', 'b', 'c'], {'a': ['z', 'a']}, ['a'], 'copy', ['a', 'b', 'q'], 'a']`	Passed
no selection	`[[], [], {}, [], 'none', [], 'c']`	`[[], [], {}, [], 'none', [], 'c']`	Passed
descendant alone	`[['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'copy', ['b'], 'b']`	`[['b'], ['b', 'c'], {'b': ['z', 'a', 'b']}, ['b'], 'move', [], 'b']`	Failed

SHA-256 / 5826d71a7f39203ed4ddaf0704a083df022a081efae7476ce9de3f5fc360ef2d

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

Synthetic deterministic hierarchical-widget data contract; not an implementation of a browser accessibility tree. 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 2026-09-29T14:43:17.745586+00:00.

Case digest / a9f8569b3d5450b678d6c1fb74e4bbe0ca560985978e086d9f2b6e12069d0c87