{"abstract":"Delta decoding omits the first absolute sample.","category":"Binary formats","checks":4,"contract":"Decode first item as absolute and later items as signed deltas.","contract_signature":"x","evaluation_group":"model-79626f8dc3773a1b","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-binary-delta-baseline","id":"FA-3726","implementations":{"attempt":{"sha256":"6d25b1e2e22b699c10e2cf4f85afb4316c962125f8f6137747d87f99cecae378","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 [sum(x[1:i+1]) for i in range(len(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([10, 2, -3]), [10, 12, 9])\ncheck('boundary 2', solve([5]), [5])\ncheck('boundary 3', solve([]), [])\ncheck('boundary 4', solve([0, 0, 1]), [0, 0, 1])\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":"415f968e0e863f13e6dee77ae660a5e6c6a5b9f4b3a52363201d0b04ee5863f2","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([10, 2, -3]), [10, 12, 9])\ncheck('boundary 2', solve([5]), [5])\ncheck('boundary 3', solve([]), [])\ncheck('boundary 4', solve([0, 0, 1]), [0, 0, 1])\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-delta-baseline","generated_at":"2026-09-29T14:37:30.062804+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 first item as absolute and later items as signed deltas.","sha256":"02220ff0488bc2ee046899fe6bd9d662289ddc30a587152788d54e0c25d60987","title":"Delta decoding omits the first absolute sample · 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":56.836,"exit_code":1,"observations":[{"actual":[0,2,-1],"check":"boundary 1","expected":[10,12,9],"passed":false},{"actual":[0],"check":"boundary 2","expected":[5],"passed":false},{"actual":[],"check":"boundary 3","expected":[],"passed":true},{"actual":[0,0,1],"check":"boundary 4","expected":[0,0,1],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [0, 2, -1], \"expected\": [10, 12, 9], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [0], \"expected\": [5], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [0, 0, 1], \"expected\": [0, 0, 1], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":52.087,"exit_code":1,"observations":[{"actual":[10,2,-3],"check":"boundary 1","expected":[10,12,9],"passed":false},{"actual":[5],"check":"boundary 2","expected":[5],"passed":true},{"actual":[],"check":"boundary 3","expected":[],"passed":true},{"actual":[0,0,1],"check":"boundary 4","expected":[0,0,1],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [10, 2, -3], \"expected\": [10, 12, 9], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [5], \"expected\": [5], \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [0, 0, 1], \"expected\": [0, 0, 1], \"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."}}