FA-53471 / Accessibility interaction semantics / Open access

CRLF consumes two places in a protected value cap · case 01

CRLF consumes two places in a protected value cap.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The newline before cap decision in the protected value adapter violates its declared contract.

THE FAILURE

The newline before cap decision in the protected value adapter violates its declared contract.

Unsuccessful approach: The local repair substitutes value = raw.replace('\r','') if cap is None else raw but still mishandles the regression fixtures.

Case contract

Input [raw,protected,reveal,permission,readonly,multiline,max_length,placeholder]. Raw is a string; max_length is None or nonnegative. Normalize CRLF before applying codepoint cap. In single line replace LF with space. Protected text reveals only when reveal and permission; otherwise one bullet per capped codepoint excluding LF, which is retained. Empty values retain empty text and expose placeholder separately. Return {text,placeholder,length,editable,protected}; length is the length after cap, editable is not readonly, protected reports input flag even when revealed.

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):
    raw,protected,reveal,permission,readonly,multiline,cap,placeholder = data
    value = raw
    if not multiline: value = value.replace('\n',' ')
    if cap is not None: value = value[:cap]
    length = len(value)
    if protected and not (reveal and permission):
        value = ''.join('\n' if c == '\n' else '•' for c in value)
    return {'text':value,'placeholder':placeholder if length == 0 else '', 'length':length,'editable':not readonly,'protected':protected}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('redacted multiline', solve(['A'*N+'\r\nB',True,False,True,False,True,None,'hint'],), {'text':'•'*N+'\n•','placeholder':'','length':N+2,'editable':True,'protected':True})
check('reveal lacks permission', solve(['A'*N,True,True,False,False,False,None,'hint'],), {'text':'•'*N,'placeholder':'','length':N,'editable':True,'protected':True})
check('permission lacks reveal', solve(['A'*N,True,False,True,False,False,None,'hint'],), {'text':'•'*N,'placeholder':'','length':N,'editable':True,'protected':True})
check('authorized reveal readonly', solve(['secret',True,True,True,True,False,None,'hint'],), {'text':'secret','placeholder':'','length':6,'editable':False,'protected':True})
check('single line cap', solve(['A\r\nBC',False,False,False,False,False,3,'hint'],), {'text':'A B','placeholder':'','length':3,'editable':True,'protected':False})
check('zero cap placeholder', solve(['secret',True,False,False,False,False,0,'hint'],), {'text':'','placeholder':'hint','length':0,'editable':True,'protected':True})
check('empty value', solve(['',False,False,False,True,False,None,'hint'],), {'text':'','placeholder':'hint','length':0,'editable':False,'protected':False})
check('unicode codepoints', solve(['😀é',True,False,False,False,True,None,''],), {'text':'••','placeholder':'','length':2,'editable':True,'protected':True})
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
redacted multiline	`{'editable': True, 'length': 4, 'placeholder': '', 'protected': True, 'text': '••\n•'}`	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': True, 'text': '•\n•'}`	Failed
reveal lacks permission	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	Passed
permission lacks reveal	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	Passed
authorized reveal readonly	`{'editable': False, 'length': 6, 'placeholder': '', 'protected': True, 'text': 'secret'}`	`{'editable': False, 'length': 6, 'placeholder': '', 'protected': True, 'text': 'secret'}`	Passed
single line cap	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': False, 'text': 'A\r '}`	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': False, 'text': 'A B'}`	Failed
zero cap placeholder	`{'editable': True, 'length': 0, 'placeholder': 'hint', 'protected': True, 'text': ''}`	`{'editable': True, 'length': 0, 'placeholder': 'hint', 'protected': True, 'text': ''}`	Passed
empty value	`{'editable': False, 'length': 0, 'placeholder': 'hint', 'protected': False, 'text': ''}`	`{'editable': False, 'length': 0, 'placeholder': 'hint', 'protected': False, 'text': ''}`	Passed
unicode codepoints	`{'editable': True, 'length': 2, 'placeholder': '', 'protected': True, 'text': '••'}`	`{'editable': True, 'length': 2, 'placeholder': '', 'protected': True, 'text': '••'}`	Passed

SHA-256 / b496d903f4ae873f8433779fd3280abe5400d6a103ee99f869164fbfb12ca65c

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(data):
    raw,protected,reveal,permission,readonly,multiline,cap,placeholder = data
    value = raw.replace('\r','') if cap is None else raw
    if not multiline: value = value.replace('\n',' ')
    if cap is not None: value = value[:cap]
    length = len(value)
    if protected and not (reveal and permission):
        value = ''.join('\n' if c == '\n' else '•' for c in value)
    return {'text':value,'placeholder':placeholder if length == 0 else '', 'length':length,'editable':not readonly,'protected':protected}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('redacted multiline', solve(['A'*N+'\r\nB',True,False,True,False,True,None,'hint'],), {'text':'•'*N+'\n•','placeholder':'','length':N+2,'editable':True,'protected':True})
check('reveal lacks permission', solve(['A'*N,True,True,False,False,False,None,'hint'],), {'text':'•'*N,'placeholder':'','length':N,'editable':True,'protected':True})
check('permission lacks reveal', solve(['A'*N,True,False,True,False,False,None,'hint'],), {'text':'•'*N,'placeholder':'','length':N,'editable':True,'protected':True})
check('authorized reveal readonly', solve(['secret',True,True,True,True,False,None,'hint'],), {'text':'secret','placeholder':'','length':6,'editable':False,'protected':True})
check('single line cap', solve(['A\r\nBC',False,False,False,False,False,3,'hint'],), {'text':'A B','placeholder':'','length':3,'editable':True,'protected':False})
check('zero cap placeholder', solve(['secret',True,False,False,False,False,0,'hint'],), {'text':'','placeholder':'hint','length':0,'editable':True,'protected':True})
check('empty value', solve(['',False,False,False,True,False,None,'hint'],), {'text':'','placeholder':'hint','length':0,'editable':False,'protected':False})
check('unicode codepoints', solve(['😀é',True,False,False,False,True,None,''],), {'text':'••','placeholder':'','length':2,'editable':True,'protected':True})
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
redacted multiline	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': True, 'text': '•\n•'}`	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': True, 'text': '•\n•'}`	Passed
reveal lacks permission	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	Passed
permission lacks reveal	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	`{'editable': True, 'length': 1, 'placeholder': '', 'protected': True, 'text': '•'}`	Passed
authorized reveal readonly	`{'editable': False, 'length': 6, 'placeholder': '', 'protected': True, 'text': 'secret'}`	`{'editable': False, 'length': 6, 'placeholder': '', 'protected': True, 'text': 'secret'}`	Passed
single line cap	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': False, 'text': 'A\r '}`	`{'editable': True, 'length': 3, 'placeholder': '', 'protected': False, 'text': 'A B'}`	Failed
zero cap placeholder	`{'editable': True, 'length': 0, 'placeholder': 'hint', 'protected': True, 'text': ''}`	`{'editable': True, 'length': 0, 'placeholder': 'hint', 'protected': True, 'text': ''}`	Passed
empty value	`{'editable': False, 'length': 0, 'placeholder': 'hint', 'protected': False, 'text': ''}`	`{'editable': False, 'length': 0, 'placeholder': 'hint', 'protected': False, 'text': ''}`	Passed
unicode codepoints	`{'editable': True, 'length': 2, 'placeholder': '', 'protected': True, 'text': '••'}`	`{'editable': True, 'length': 2, 'placeholder': '', 'protected': True, 'text': '••'}`	Passed

SHA-256 / 55ebec6e484a03116f6983a1c9560c267dac37d31af39691a55debf152409e27

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 8 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

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 2026-09-29T14:45:39.776231+00:00.

Case digest / 2ea576af07b5e9885df19b1f9f7843a3c78200b8bcfa8bffd1dd2505ce649617