{"abstract":"Escaped frame markers are decoded as delimiters.","category":"Binary formats","checks":4,"contract":"Decode 0x7D escapes by XOR 0x20; other bytes are literal, dangling escape rejects.","contract_signature":"x","evaluation_group":"model-3cc60af8c840e9be","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-binary-byte-stuffing","id":"FA-3716","implementations":{"attempt":{"sha256":"963c67c6aff7b75a4fbcbd62e4c15f20032de39c7415d19df6eb1564e80cd193","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return [x[i+1]^32 if v==125 and i+1<len(x) else v for i,v in enumerate(x) if i==0 or x[i-1]!=125]\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve([125, 125, 65]), [93, 65])\ncheck('boundary 2', solve([125]), None)\ncheck('boundary 3', solve([125, 94]), [126])\ncheck('boundary 4', solve([]), [])\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":"c4b893bbb2ee4758da6b69df9aa8708cc769515f1e8e6a5ad8e4ec1662be39df","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return [v for v in x if v!=125]\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve([125, 125, 65]), [93, 65])\ncheck('boundary 2', solve([125]), None)\ncheck('boundary 3', solve([125, 94]), [126])\ncheck('boundary 4', solve([]), [])\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":" 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":"xp-binary-byte-stuffing","generated_at":"2026-09-29T14:37:30.007487+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Decode 0x7D escapes by XOR 0x20; other bytes are literal, dangling escape rejects.","sha256":"53d7c01be887c78ffbae0ea5481e439aed85b7a1b098840fce6417a947c9d8a3","title":"Escaped frame markers are decoded as delimiters · 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":53.479,"exit_code":1,"observations":[{"actual":[93],"check":"boundary 1","expected":[93,65],"passed":false},{"actual":[125],"check":"boundary 2","expected":null,"passed":false},{"actual":[126],"check":"boundary 3","expected":[126],"passed":true},{"actual":[],"check":"boundary 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [93], \"expected\": [93, 65], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [125], \"expected\": null, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [126], \"expected\": [126], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":54.379,"exit_code":1,"observations":[{"actual":[65],"check":"boundary 1","expected":[93,65],"passed":false},{"actual":[],"check":"boundary 2","expected":null,"passed":false},{"actual":[94],"check":"boundary 3","expected":[126],"passed":false},{"actual":[],"check":"boundary 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [65], \"expected\": [93, 65], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [], \"expected\": null, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [94], \"expected\": [126], \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"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."}}