{"abstract":"Each received part needs its own explicit range metadata.","category":"HTTP ranges","checks":6,"contract":"parts are [content-range-or-null,body]. Return bodies only when every part has range metadata; never inherit a preceding range.","contract_signature":"parts","evaluation_group":"s3-http_ranges-multipart-client","failed_approach":"The partial repair uses return [b for r,b in parts] if not parts or parts[0][0] is not None else None, which still violates the stated contract.","family":"s3-http_ranges-multipart-client-missing-range","id":"FA-26816","implementations":{"attempt":{"sha256":"15ae60e81408b9623e34a031b9f43722ce703f2e028899385717cfb3c681c0d5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts):\n    return [b for r,b in parts] if not parts or parts[0][0] is not None else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-client-missing-range fixture 0', solve([[\"r\",\"a\"*N],[None,\"b\"]]), None)\ncheck('multipart-client-missing-range fixture 1', solve([[None,\"a\"]]), None)\ncheck('multipart-client-missing-range fixture 2', solve([[\"r\",\"a\"*N]]), [\"a\"*N])\ncheck('multipart-client-missing-range fixture 3', solve([]), [])\ncheck('multipart-client-missing-range fixture 4', solve([[\"r\",\"\"],[\"s\",\"b\"]]), [\"\",\"b\"])\ncheck('multipart-client-missing-range fixture 5', solve([[\"r\",\"a\"],[\"s\",\"b\"]]), [\"a\",\"b\"])\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":"4521e8f1e5db9b27f2cecf211d60bba28644abfdf1564ebefa1deeffe57a0fc8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts):\n    return [b for r,b in parts]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-client-missing-range fixture 0', solve([[\"r\",\"a\"*N],[None,\"b\"]]), None)\ncheck('multipart-client-missing-range fixture 1', solve([[None,\"a\"]]), None)\ncheck('multipart-client-missing-range fixture 2', solve([[\"r\",\"a\"*N]]), [\"a\"*N])\ncheck('multipart-client-missing-range fixture 3', solve([]), [])\ncheck('multipart-client-missing-range fixture 4', solve([[\"r\",\"\"],[\"s\",\"b\"]]), [\"\",\"b\"])\ncheck('multipart-client-missing-range fixture 5', solve([[\"r\",\"a\"],[\"s\",\"b\"]]), [\"a\",\"b\"])\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 simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. 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-http_ranges-multipart-client-missing-range","generated_at":"2026-09-29T14:41:19.383894+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Range responses combine representation identity, conditional requests, framing, and partial-object state.","root_cause":"The multipart-client-missing-range decision uses return [b for r,b in parts].","sha256":"b51405cb4f67f4499cbdd5448bd1c08be028d8e8342231b24484b1943ee42d83","title":"Each received part needs its own explicit range metadata · 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":39.831,"exit_code":1,"observations":[{"actual":["a","b"],"check":"multipart-client-missing-range fixture 0","expected":null,"passed":false},{"actual":null,"check":"multipart-client-missing-range fixture 1","expected":null,"passed":true},{"actual":["a"],"check":"multipart-client-missing-range fixture 2","expected":["a"],"passed":true},{"actual":[],"check":"multipart-client-missing-range fixture 3","expected":[],"passed":true},{"actual":["","b"],"check":"multipart-client-missing-range fixture 4","expected":["","b"],"passed":true},{"actual":["a","b"],"check":"multipart-client-missing-range fixture 5","expected":["a","b"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-client-missing-range fixture 0\", \"actual\": [\"a\", \"b\"], \"expected\": null, \"passed\": false}, {\"check\": \"multipart-client-missing-range fixture 1\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 2\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 4\", \"actual\": [\"\", \"b\"], \"expected\": [\"\", \"b\"], \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 5\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.21,"exit_code":1,"observations":[{"actual":["a","b"],"check":"multipart-client-missing-range fixture 0","expected":null,"passed":false},{"actual":["a"],"check":"multipart-client-missing-range fixture 1","expected":null,"passed":false},{"actual":["a"],"check":"multipart-client-missing-range fixture 2","expected":["a"],"passed":true},{"actual":[],"check":"multipart-client-missing-range fixture 3","expected":[],"passed":true},{"actual":["","b"],"check":"multipart-client-missing-range fixture 4","expected":["","b"],"passed":true},{"actual":["a","b"],"check":"multipart-client-missing-range fixture 5","expected":["a","b"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-client-missing-range fixture 0\", \"actual\": [\"a\", \"b\"], \"expected\": null, \"passed\": false}, {\"check\": \"multipart-client-missing-range fixture 1\", \"actual\": [\"a\"], \"expected\": null, \"passed\": false}, {\"check\": \"multipart-client-missing-range fixture 2\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 4\", \"actual\": [\"\", \"b\"], \"expected\": [\"\", \"b\"], \"passed\": true}, {\"check\": \"multipart-client-missing-range fixture 5\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\"], \"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."}}