{"abstract":"A structured table violates the declared record or column contract.","category":"Delimited text","checks":8,"contract":"Decode TSV fields with exactly four escapes: backslash-t, backslash-n, backslash-r, backslash-backslash. Raw tabs split fields, raw newlines are forbidden; unknown and dangling escapes reject the row. Empty input is one empty field.","contract_signature":"data","evaluation_group":"s3-delimited-text-escaped-tsv-reader","failed_approach":"Keeping a suffix still leaks the preceding cell into an empty successor.","family":"s3-delimited-text-escaped-tsv-reader-flush-reset","id":"FA-47401","implementations":{"attempt":{"sha256":"f21ac50e0e3a08e2a5dd7ddf2b0c65fdf032c01c7e041de5083b2a86fdb40346","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    out, field, escaped = [], [], False\n    for ch in data:\n        if escaped:\n            if ch not in 'tnr\\\\': return None\n            field.append({'t':'\\t','n':'\\n','r':'\\r','\\\\':'\\\\'}[ch])\n            escaped = False\n        elif ch == '\\\\': escaped = True\n        elif ch == '\\t':\n            out.append(''.join(field))\n            field = field[-1:]\n        elif ch in '\\r\\n': return None\n        else: field.append(ch)\n    if escaped: return None\n    out.append(''.join(field))\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('mapped escapes', solve(_vary('@\\\\tA\\\\nB\\\\rC\\\\\\\\D')), _vary(['@\\tA\\nB\\rC\\\\D']))\ncheck('separators', solve(_vary('@\\t\\tZ')), _vary(['@', '', 'Z']))\ncheck('escaped backslash then t', solve(_vary('\\\\\\\\t')), _vary(['\\\\t']))\ncheck('unknown', solve(_vary('\\\\q')), _vary(None))\ncheck('dangling', solve(_vary('@\\\\')), _vary(None))\ncheck('raw newline', solve(_vary('@\\nZ')), _vary(None))\ncheck('empty', solve(_vary('')), _vary(['']))\ncheck('leading trailing', solve(_vary('\\t@\\t')), _vary(['', '@', '']))\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"3d1213dd0385df16a36eb2b0ed7c6bd842c1c6cf3b188afb1f32f3197e6b90e6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    out, field, escaped = [], [], False\n    for ch in data:\n        if escaped:\n            if ch not in 'tnr\\\\': return None\n            field.append({'t':'\\t','n':'\\n','r':'\\r','\\\\':'\\\\'}[ch])\n            escaped = False\n        elif ch == '\\\\': escaped = True\n        elif ch == '\\t':\n            out.append(''.join(field))\n            field = field\n        elif ch in '\\r\\n': return None\n        else: field.append(ch)\n    if escaped: return None\n    out.append(''.join(field))\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('mapped escapes', solve(_vary('@\\\\tA\\\\nB\\\\rC\\\\\\\\D')), _vary(['@\\tA\\nB\\rC\\\\D']))\ncheck('separators', solve(_vary('@\\t\\tZ')), _vary(['@', '', 'Z']))\ncheck('escaped backslash then t', solve(_vary('\\\\\\\\t')), _vary(['\\\\t']))\ncheck('unknown', solve(_vary('\\\\q')), _vary(None))\ncheck('dangling', solve(_vary('@\\\\')), _vary(None))\ncheck('raw newline', solve(_vary('@\\nZ')), _vary(None))\ncheck('empty', solve(_vary('')), _vary(['']))\ncheck('leading trailing', solve(_vary('\\t@\\t')), _vary(['', '@', '']))\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Deterministic bounded in-memory model. No claim of complete CSV or external format 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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"s3-delimited-text-escaped-tsv-reader-flush-reset","generated_at":"2026-09-29T14:44:41.176248+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Delimited interchange needs explicit framing, schema and field semantics at ingestion and emission boundaries.","root_cause":"Field emission does not clear the buffer before the next column.","sha256":"63f606f06c170d78189ed5ec6883911ddae2805aa53383b04d1dce1c0a21eb40","title":"TSV fields retain the previous column buffer · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":47.09,"exit_code":1,"observations":[{"actual":["cell\tA\nB\rC\\D"],"check":"mapped escapes","expected":["cell\tA\nB\rC\\D"],"passed":true},{"actual":["cell","l","lZ"],"check":"separators","expected":["cell","","Z"],"passed":false},{"actual":["\\t"],"check":"escaped backslash then t","expected":["\\t"],"passed":true},{"actual":null,"check":"unknown","expected":null,"passed":true},{"actual":null,"check":"dangling","expected":null,"passed":true},{"actual":null,"check":"raw newline","expected":null,"passed":true},{"actual":[""],"check":"empty","expected":[""],"passed":true},{"actual":["","cell","l"],"check":"leading trailing","expected":["","cell",""],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"mapped escapes\", \"actual\": [\"cell\\tA\\nB\\rC\\\\D\"], \"expected\": [\"cell\\tA\\nB\\rC\\\\D\"], \"passed\": true}, {\"check\": \"separators\", \"actual\": [\"cell\", \"l\", \"lZ\"], \"expected\": [\"cell\", \"\", \"Z\"], \"passed\": false}, {\"check\": \"escaped backslash then t\", \"actual\": [\"\\\\t\"], \"expected\": [\"\\\\t\"], \"passed\": true}, {\"check\": \"unknown\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"dangling\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"raw newline\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}, {\"check\": \"leading trailing\", \"actual\": [\"\", \"cell\", \"l\"], \"expected\": [\"\", \"cell\", \"\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.968,"exit_code":1,"observations":[{"actual":["cell\tA\nB\rC\\D"],"check":"mapped escapes","expected":["cell\tA\nB\rC\\D"],"passed":true},{"actual":["cell","cell","cellZ"],"check":"separators","expected":["cell","","Z"],"passed":false},{"actual":["\\t"],"check":"escaped backslash then t","expected":["\\t"],"passed":true},{"actual":null,"check":"unknown","expected":null,"passed":true},{"actual":null,"check":"dangling","expected":null,"passed":true},{"actual":null,"check":"raw newline","expected":null,"passed":true},{"actual":[""],"check":"empty","expected":[""],"passed":true},{"actual":["","cell","cell"],"check":"leading trailing","expected":["","cell",""],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"mapped escapes\", \"actual\": [\"cell\\tA\\nB\\rC\\\\D\"], \"expected\": [\"cell\\tA\\nB\\rC\\\\D\"], \"passed\": true}, {\"check\": \"separators\", \"actual\": [\"cell\", \"cell\", \"cellZ\"], \"expected\": [\"cell\", \"\", \"Z\"], \"passed\": false}, {\"check\": \"escaped backslash then t\", \"actual\": [\"\\\\t\"], \"expected\": [\"\\\\t\"], \"passed\": true}, {\"check\": \"unknown\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"dangling\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"raw newline\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}, {\"check\": \"leading trailing\", \"actual\": [\"\", \"cell\", \"cell\"], \"expected\": [\"\", \"cell\", \"\"], \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}