{"abstract":"A terminated field consumes padding after the first zero.","category":"Binary formats","checks":4,"contract":"Return bytes before the first zero; reject input without a zero.","evaluation_group":"model-5e18314a161339bc","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-binary-null-terminated","id":"FA-3666","implementations":{"attempt":{"sha256":"d58902202a8e3d9292d76e028a206b4c032d928b40c792b235ff592cefb75b47","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]\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([65, 0, 66]), [65])\ncheck('boundary 2', solve([0, 65]), [])\ncheck('boundary 3', solve([65]), None)\ncheck('boundary 4', solve([65, 66, 0]), [65, 66])\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":"63f1210c7a66e3141d1dfd72e3dc7e0809562a73c8c2b0ccb680256b62927cdc","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\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([65, 0, 66]), [65])\ncheck('boundary 2', solve([0, 65]), [])\ncheck('boundary 3', solve([65]), None)\ncheck('boundary 4', solve([65, 66, 0]), [65, 66])\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"},"fixed":{"sha256":"0741b3ca3bcdccc15baccfbe110d98594ab1fc9fc91561f8c777f83241e0a897","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[:x.index(0)] if 0 in x else None\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([65, 0, 66]), [65])\ncheck('boundary 2', solve([0, 65]), [])\ncheck('boundary 3', solve([65]), None)\ncheck('boundary 4', solve([65, 66, 0]), [65, 66])\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-null-terminated","generated_at":"2026-09-29T14:37:29.173934+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.","repair":"Implement the complete stated contract, including the boundary fixtures: Return bytes before the first zero; reject input without a zero.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Return bytes before the first zero; reject input without a zero.","sha256":"044fa9e8333dc8da126b8a81d74db072e126dfd59c8122ccc9ed3781ac10cadb","title":"A terminated field consumes padding after the first zero · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":53.213,"exit_code":1,"observations":[{"actual":[65,66],"check":"boundary 1","expected":[65],"passed":false},{"actual":[65],"check":"boundary 2","expected":[],"passed":false},{"actual":[65],"check":"boundary 3","expected":null,"passed":false},{"actual":[65,66],"check":"boundary 4","expected":[65,66],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [65, 66], \"expected\": [65], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [65], \"expected\": [], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [65], \"expected\": null, \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": [65, 66], \"expected\": [65, 66], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":49.913,"exit_code":1,"observations":[{"actual":[65,0,66],"check":"boundary 1","expected":[65],"passed":false},{"actual":[0,65],"check":"boundary 2","expected":[],"passed":false},{"actual":[65],"check":"boundary 3","expected":null,"passed":false},{"actual":[65,66,0],"check":"boundary 4","expected":[65,66],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [65, 0, 66], \"expected\": [65], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [0, 65], \"expected\": [], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [65], \"expected\": null, \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": [65, 66, 0], \"expected\": [65, 66], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":52.449,"exit_code":0,"observations":[{"actual":[65],"check":"boundary 1","expected":[65],"passed":true},{"actual":[],"check":"boundary 2","expected":[],"passed":true},{"actual":null,"check":"boundary 3","expected":null,"passed":true},{"actual":[65,66],"check":"boundary 4","expected":[65,66],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [65], \"expected\": [65], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [65, 66], \"expected\": [65, 66], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}