FA-54211 / Accessibility interaction semantics / Open access
Protected content tokens leak through the braille bridge · case 01
Protected content tokens leak through the braille bridge.
ROOT CAUSE
The protected cells decision in the braille routing adapter violates its declared contract.
VERIFIED REPAIR
Apply the exact contract at the protected cells decision: '•' if c == 'SECRET' else (c if c else ' ')
Unsuccessful approach: The local repair substitutes '*' if c == 'SECRET' else (c if c else ' ') but still mishandles the regression fixtures.
Case contract
Input [cells,offset,width,route] where cells [source_start,source_end,content,editable]. Clip display window by nonnegative offset and width. Each cell has one display position regardless of content length. Routing uses a zero-based position inside displayed cells; return None if outside window or cell not editable, otherwise [source_start,source_end]. Display contents replace empty cell content with a space; protected content (exact token SECRET) displays a bullet. Return [display,source_ranges,route_result,has_previous,has_next]. Source ranges preserve zero-width insertion cells.
Why this case matters
Offline accessibility bridge model with explicit policy; useful for testing semantic API adapters independently of browser implementations.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(data):
cells,offset,width,route = data
offset,width = max(0,offset),max(0,width)
window = cells[offset:offset+width]
contents = [(c if c else ' ') for s,e,c,editable in window]
ranges = [[s,e] for s,e,c,editable in window]
routed = None
if 0 <= route < len(window):
s,e,c,editable = window[route]
if editable: routed = [s,e]
return [contents,ranges,routed,offset>0,offset+len(window)<len(cells)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([[[0,N,'ab',True],[N,N+2,'SECRET',False],[N+2,N+2,'',True]],1,2,1],), [['•',' '],[[N,N+2],[N+2,N+2]],[N+2,N+2],True,False])
check('contract fixture 2', solve([[[0,2,'ab',True],[2,3,'c',True],[3,4,'d',True]],0,2,0],), [['ab','c'],[[0,2],[2,3]],[0,2],False,True])
check('contract fixture 3', solve([[[0,1,'x',False]],0,1,0],), [['x'],[[0,1]],None,False,False])
check('contract fixture 4', solve([[[0,1,'x',True]],0,1,-1],), [['x'],[[0,1]],None,False,False])
check('contract fixture 5', solve([[[0,1,'x',True]],0,1,1],), [['x'],[[0,1]],None,False,False])
check('contract fixture 6', solve([[[0,1,'x',True]],-2,0,0],), [[],[],None,False,True])
check('contract fixture 7', solve([[[0,1,'a',True],[1,2,'b',True]],-1,1,0],), [['a'],[[0,1]],[0,1],False,True])
check('contract fixture 8', solve([[],0,4,0],), [[],[],None,False,False])
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 |
|---|---|---|---|
| contract fixture 1 | [['SECRET', ' '], [[1, 3], [3, 3]], [3, 3], True, False] | [['•', ' '], [[1, 3], [3, 3]], [3, 3], True, False] | Failed |
| contract fixture 2 | [['ab', 'c'], [[0, 2], [2, 3]], [0, 2], False, True] | [['ab', 'c'], [[0, 2], [2, 3]], [0, 2], False, True] | Passed |
| contract fixture 3 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 4 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 5 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 6 | [[], [], None, False, True] | [[], [], None, False, True] | Passed |
| contract fixture 7 | [['a'], [[0, 1]], [0, 1], False, True] | [['a'], [[0, 1]], [0, 1], False, True] | Passed |
| contract fixture 8 | [[], [], None, False, False] | [[], [], None, False, False] | Passed |
SHA-256 / 17e3a8cb76d3da4b0ef6e8537187bc9a1541888093e5cb760c07e6de754b6d00
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(data):
cells,offset,width,route = data
offset,width = max(0,offset),max(0,width)
window = cells[offset:offset+width]
contents = [('*' if c == 'SECRET' else (c if c else ' ')) for s,e,c,editable in window]
ranges = [[s,e] for s,e,c,editable in window]
routed = None
if 0 <= route < len(window):
s,e,c,editable = window[route]
if editable: routed = [s,e]
return [contents,ranges,routed,offset>0,offset+len(window)<len(cells)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([[[0,N,'ab',True],[N,N+2,'SECRET',False],[N+2,N+2,'',True]],1,2,1],), [['•',' '],[[N,N+2],[N+2,N+2]],[N+2,N+2],True,False])
check('contract fixture 2', solve([[[0,2,'ab',True],[2,3,'c',True],[3,4,'d',True]],0,2,0],), [['ab','c'],[[0,2],[2,3]],[0,2],False,True])
check('contract fixture 3', solve([[[0,1,'x',False]],0,1,0],), [['x'],[[0,1]],None,False,False])
check('contract fixture 4', solve([[[0,1,'x',True]],0,1,-1],), [['x'],[[0,1]],None,False,False])
check('contract fixture 5', solve([[[0,1,'x',True]],0,1,1],), [['x'],[[0,1]],None,False,False])
check('contract fixture 6', solve([[[0,1,'x',True]],-2,0,0],), [[],[],None,False,True])
check('contract fixture 7', solve([[[0,1,'a',True],[1,2,'b',True]],-1,1,0],), [['a'],[[0,1]],[0,1],False,True])
check('contract fixture 8', solve([[],0,4,0],), [[],[],None,False,False])
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 |
|---|---|---|---|
| contract fixture 1 | [['*', ' '], [[1, 3], [3, 3]], [3, 3], True, False] | [['•', ' '], [[1, 3], [3, 3]], [3, 3], True, False] | Failed |
| contract fixture 2 | [['ab', 'c'], [[0, 2], [2, 3]], [0, 2], False, True] | [['ab', 'c'], [[0, 2], [2, 3]], [0, 2], False, True] | Passed |
| contract fixture 3 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 4 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 5 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 6 | [[], [], None, False, True] | [[], [], None, False, True] | Passed |
| contract fixture 7 | [['a'], [[0, 1]], [0, 1], False, True] | [['a'], [[0, 1]], [0, 1], False, True] | Passed |
| contract fixture 8 | [[], [], None, False, False] | [[], [], None, False, False] | Passed |
SHA-256 / 57548f7e319eb3a47f499920c4b5337c4a7da35b8e0db343ecefce29143c1eaa
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(data):
cells,offset,width,route = data
offset,width = max(0,offset),max(0,width)
window = cells[offset:offset+width]
contents = [('•' if c == 'SECRET' else (c if c else ' ')) for s,e,c,editable in window]
ranges = [[s,e] for s,e,c,editable in window]
routed = None
if 0 <= route < len(window):
s,e,c,editable = window[route]
if editable: routed = [s,e]
return [contents,ranges,routed,offset>0,offset+len(window)<len(cells)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([[[0,N,'ab',True],[N,N+2,'SECRET',False],[N+2,N+2,'',True]],1,2,1],), [['•',' '],[[N,N+2],[N+2,N+2]],[N+2,N+2],True,False])
check('contract fixture 2', solve([[[0,2,'ab',True],[2,3,'c',True],[3,4,'d',True]],0,2,0],), [['ab','c'],[[0,2],[2,3]],[0,2],False,True])
check('contract fixture 3', solve([[[0,1,'x',False]],0,1,0],), [['x'],[[0,1]],None,False,False])
check('contract fixture 4', solve([[[0,1,'x',True]],0,1,-1],), [['x'],[[0,1]],None,False,False])
check('contract fixture 5', solve([[[0,1,'x',True]],0,1,1],), [['x'],[[0,1]],None,False,False])
check('contract fixture 6', solve([[[0,1,'x',True]],-2,0,0],), [[],[],None,False,True])
check('contract fixture 7', solve([[[0,1,'a',True],[1,2,'b',True]],-1,1,0],), [['a'],[[0,1]],[0,1],False,True])
check('contract fixture 8', solve([[],0,4,0],), [[],[],None,False,False])
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 |
|---|---|---|---|
| contract fixture 1 | [['•', ' '], [[1, 3], [3, 3]], [3, 3], True, False] | [['•', ' '], [[1, 3], [3, 3]], [3, 3], True, False] | Passed |
| contract fixture 2 | [['ab', 'c'], [[0, 2], [2, 3]], [0, 2], False, True] | [['ab', 'c'], [[0, 2], [2, 3]], [0, 2], False, True] | Passed |
| contract fixture 3 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 4 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 5 | [['x'], [[0, 1]], None, False, False] | [['x'], [[0, 1]], None, False, False] | Passed |
| contract fixture 6 | [[], [], None, False, True] | [[], [], None, False, True] | Passed |
| contract fixture 7 | [['a'], [[0, 1]], [0, 1], False, True] | [['a'], [[0, 1]], [0, 1], False, True] | Passed |
| contract fixture 8 | [[], [], None, False, False] | [[], [], None, False, False] | Passed |
SHA-256 / 9366225523c4f8d0d94e6737016ceee05746c3c7b4829d345dbeaa6ea661fe4d
Verification & scope
Stipulated finite adapter contract, not a claim of platform accessibility or ARIA 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 2026-09-29T14:45:46.283140+00:00.
Case digest / 3be72b76a6a469fc61ade7d732046ceb70c1fe1b2ea0bd3688cef7ca2d9cd110