{"abstract":"Run-length decoding treats zero count as one.","category":"Binary formats","checks":4,"contract":"Decode count/value pairs, allow zero counts, and reject an odd-length stream.","contract_signature":"x","evaluation_group":"model-14cf329a37d393e5","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-binary-rle-zero-run","id":"FA-3706","implementations":{"attempt":{"sha256":"de98a15facb497128bd350f1c63c4585e91eeef5ed97f4e5ecb8135ec0a2f173","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 n,v in zip(x[::2],x[1::2]) for _ in range(n)]\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([0, 65]), [])\ncheck('boundary 2', solve([2, 65, 1]), None)\ncheck('boundary 3', solve([2, 65, 1, 66]), [65, 65, 66])\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":"04f1d88fdad87e0e2d53e0fa79d4284008045f2c2c7b928912bc8f5c1e98b09f","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 n,v in zip(x[::2],x[1::2]) for _ in range(max(n,1))]\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([0, 65]), [])\ncheck('boundary 2', solve([2, 65, 1]), None)\ncheck('boundary 3', solve([2, 65, 1, 66]), [65, 65, 66])\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-rle-zero-run","generated_at":"2026-09-29T14:37:29.723128+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 count/value pairs, allow zero counts, and reject an odd-length stream.","sha256":"a585034ddf9305dd4aaa4020ffbbb3e805d851248c98d21769fa29b512fb2d21","title":"Run-length decoding treats zero count as one · 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":53.421,"exit_code":1,"observations":[{"actual":[],"check":"boundary 1","expected":[],"passed":true},{"actual":[65,65],"check":"boundary 2","expected":null,"passed":false},{"actual":[65,65,66],"check":"boundary 3","expected":[65,65,66],"passed":true},{"actual":[],"check":"boundary 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [65, 65], \"expected\": null, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [65, 65, 66], \"expected\": [65, 65, 66], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":56.305,"exit_code":1,"observations":[{"actual":[65],"check":"boundary 1","expected":[],"passed":false},{"actual":[65,65],"check":"boundary 2","expected":null,"passed":false},{"actual":[65,65,66],"check":"boundary 3","expected":[65,65,66],"passed":true},{"actual":[],"check":"boundary 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [65], \"expected\": [], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [65, 65], \"expected\": null, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [65, 65, 66], \"expected\": [65, 65, 66], \"passed\": true}, {\"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."}}