{"abstract":"Top-level range metadata is absent for multipart bodies.","category":"HTTP ranges","checks":6,"contract":"Return [top-content-range,part-ranges]. A singleton uses its individual range at top and no per-part list; multiple parts have null top and all per-part ranges.","evaluation_group":"s3-http_ranges-multipart","failed_approach":"The partial repair uses return [None,individual], which still violates the stated contract.","family":"s3-http_ranges-multipart-no-top-content-range","id":"FA-26471","implementations":{"attempt":{"sha256":"7d698ad113d80922fd00c4844595e3a0cb1318990aa29dc45b8baea14158493f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts, individual):\n    return [None,individual]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-no-top-content-range fixture 0', solve(2,[\"a\"+str(N),\"b\"]), [None,[\"a\"+str(N),\"b\"]])\ncheck('multipart-no-top-content-range fixture 1', solve(1,[\"a\"+str(N)]), [\"a\"+str(N),[]])\ncheck('multipart-no-top-content-range fixture 2', solve(0,[]), [None,[]])\ncheck('multipart-no-top-content-range fixture 3', solve(3,[\"a\",\"b\",\"c\"]), [None,[\"a\",\"b\",\"c\"]])\ncheck('multipart-no-top-content-range fixture 4', solve(1,[\"\"]), [\"\",[]])\ncheck('multipart-no-top-content-range fixture 5', solve(2,[\"a\",\"a\"]), [None,[\"a\",\"a\"]])\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":"e2065db715a75b947f0a9233222592e0db2a168dccf38fee7a35fc0466e9bc9c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts, individual):\n    return [individual[0] if individual else None,individual]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-no-top-content-range fixture 0', solve(2,[\"a\"+str(N),\"b\"]), [None,[\"a\"+str(N),\"b\"]])\ncheck('multipart-no-top-content-range fixture 1', solve(1,[\"a\"+str(N)]), [\"a\"+str(N),[]])\ncheck('multipart-no-top-content-range fixture 2', solve(0,[]), [None,[]])\ncheck('multipart-no-top-content-range fixture 3', solve(3,[\"a\",\"b\",\"c\"]), [None,[\"a\",\"b\",\"c\"]])\ncheck('multipart-no-top-content-range fixture 4', solve(1,[\"\"]), [\"\",[]])\ncheck('multipart-no-top-content-range fixture 5', solve(2,[\"a\",\"a\"]), [None,[\"a\",\"a\"]])\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":"6aff7e851d5fec2567f02a212e09c060959f59740678b0fe717f5238792fce65","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts, individual):\n    return [individual[0],[]] if parts==1 else [None,individual]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-no-top-content-range fixture 0', solve(2,[\"a\"+str(N),\"b\"]), [None,[\"a\"+str(N),\"b\"]])\ncheck('multipart-no-top-content-range fixture 1', solve(1,[\"a\"+str(N)]), [\"a\"+str(N),[]])\ncheck('multipart-no-top-content-range fixture 2', solve(0,[]), [None,[]])\ncheck('multipart-no-top-content-range fixture 3', solve(3,[\"a\",\"b\",\"c\"]), [None,[\"a\",\"b\",\"c\"]])\ncheck('multipart-no-top-content-range fixture 4', solve(1,[\"\"]), [\"\",[]])\ncheck('multipart-no-top-content-range fixture 5', solve(2,[\"a\",\"a\"]), [None,[\"a\",\"a\"]])\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-no-top-content-range","generated_at":"2026-09-29T14:41:16.292990+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.","repair":"Apply the bounded decision exactly: return [individual[0],[]] if parts==1 else [None,individual]","root_cause":"The multipart-no-top-content-range decision uses return [individual[0] if individual else None,individual].","sha256":"a0ab7147c0923e4655e786ba26b7f495c1791043ceafe0e25e6895e2766d38d4","title":"Top-level range metadata is absent for multipart bodies · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.115,"exit_code":1,"observations":[{"actual":[null,["a1","b"]],"check":"multipart-no-top-content-range fixture 0","expected":[null,["a1","b"]],"passed":true},{"actual":[null,["a1"]],"check":"multipart-no-top-content-range fixture 1","expected":["a1",[]],"passed":false},{"actual":[null,[]],"check":"multipart-no-top-content-range fixture 2","expected":[null,[]],"passed":true},{"actual":[null,["a","b","c"]],"check":"multipart-no-top-content-range fixture 3","expected":[null,["a","b","c"]],"passed":true},{"actual":[null,[""]],"check":"multipart-no-top-content-range fixture 4","expected":["",[]],"passed":false},{"actual":[null,["a","a"]],"check":"multipart-no-top-content-range fixture 5","expected":[null,["a","a"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-no-top-content-range fixture 0\", \"actual\": [null, [\"a1\", \"b\"]], \"expected\": [null, [\"a1\", \"b\"]], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 1\", \"actual\": [null, [\"a1\"]], \"expected\": [\"a1\", []], \"passed\": false}, {\"check\": \"multipart-no-top-content-range fixture 2\", \"actual\": [null, []], \"expected\": [null, []], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 3\", \"actual\": [null, [\"a\", \"b\", \"c\"]], \"expected\": [null, [\"a\", \"b\", \"c\"]], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 4\", \"actual\": [null, [\"\"]], \"expected\": [\"\", []], \"passed\": false}, {\"check\": \"multipart-no-top-content-range fixture 5\", \"actual\": [null, [\"a\", \"a\"]], \"expected\": [null, [\"a\", \"a\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.584,"exit_code":1,"observations":[{"actual":["a1",["a1","b"]],"check":"multipart-no-top-content-range fixture 0","expected":[null,["a1","b"]],"passed":false},{"actual":["a1",["a1"]],"check":"multipart-no-top-content-range fixture 1","expected":["a1",[]],"passed":false},{"actual":[null,[]],"check":"multipart-no-top-content-range fixture 2","expected":[null,[]],"passed":true},{"actual":["a",["a","b","c"]],"check":"multipart-no-top-content-range fixture 3","expected":[null,["a","b","c"]],"passed":false},{"actual":["",[""]],"check":"multipart-no-top-content-range fixture 4","expected":["",[]],"passed":false},{"actual":["a",["a","a"]],"check":"multipart-no-top-content-range fixture 5","expected":[null,["a","a"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-no-top-content-range fixture 0\", \"actual\": [\"a1\", [\"a1\", \"b\"]], \"expected\": [null, [\"a1\", \"b\"]], \"passed\": false}, {\"check\": \"multipart-no-top-content-range fixture 1\", \"actual\": [\"a1\", [\"a1\"]], \"expected\": [\"a1\", []], \"passed\": false}, {\"check\": \"multipart-no-top-content-range fixture 2\", \"actual\": [null, []], \"expected\": [null, []], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 3\", \"actual\": [\"a\", [\"a\", \"b\", \"c\"]], \"expected\": [null, [\"a\", \"b\", \"c\"]], \"passed\": false}, {\"check\": \"multipart-no-top-content-range fixture 4\", \"actual\": [\"\", [\"\"]], \"expected\": [\"\", []], \"passed\": false}, {\"check\": \"multipart-no-top-content-range fixture 5\", \"actual\": [\"a\", [\"a\", \"a\"]], \"expected\": [null, [\"a\", \"a\"]], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.378,"exit_code":0,"observations":[{"actual":[null,["a1","b"]],"check":"multipart-no-top-content-range fixture 0","expected":[null,["a1","b"]],"passed":true},{"actual":["a1",[]],"check":"multipart-no-top-content-range fixture 1","expected":["a1",[]],"passed":true},{"actual":[null,[]],"check":"multipart-no-top-content-range fixture 2","expected":[null,[]],"passed":true},{"actual":[null,["a","b","c"]],"check":"multipart-no-top-content-range fixture 3","expected":[null,["a","b","c"]],"passed":true},{"actual":["",[]],"check":"multipart-no-top-content-range fixture 4","expected":["",[]],"passed":true},{"actual":[null,["a","a"]],"check":"multipart-no-top-content-range fixture 5","expected":[null,["a","a"]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-no-top-content-range fixture 0\", \"actual\": [null, [\"a1\", \"b\"]], \"expected\": [null, [\"a1\", \"b\"]], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 1\", \"actual\": [\"a1\", []], \"expected\": [\"a1\", []], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 2\", \"actual\": [null, []], \"expected\": [null, []], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 3\", \"actual\": [null, [\"a\", \"b\", \"c\"]], \"expected\": [null, [\"a\", \"b\", \"c\"]], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 4\", \"actual\": [\"\", []], \"expected\": [\"\", []], \"passed\": true}, {\"check\": \"multipart-no-top-content-range fixture 5\", \"actual\": [null, [\"a\", \"a\"]], \"expected\": [null, [\"a\", \"a\"]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}