{"abstract":"Range metadata uses the negotiated variant length.","category":"HTTP ranges","checks":6,"contract":"Return content-range metadata as [start,stop,selected-length] for already valid inclusive bounds; selected encoding is identity or encoded.","evaluation_group":"s3-http_ranges-representation","failed_approach":"The partial repair uses return [start,stop,max(len(plain),len(encoded))], which still violates the stated contract.","family":"s3-http_ranges-selected-length-metadata","id":"FA-26396","implementations":{"attempt":{"sha256":"ff23ddc66117e9176ccb6694ae5f6a534e88bfeb0f85761f6e78403bc02d9158","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(plain, encoded, coding, start, stop):\n    return [start,stop,max(len(plain),len(encoded))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('selected-length-metadata fixture 0', solve(\"abcdef\"*N,\"XYZ\"*N,\"encoded\",0,1), [0,1,3*N])\ncheck('selected-length-metadata fixture 1', solve(\"ab\",\"WXYZ\",\"identity\",0,1), [0,1,2])\ncheck('selected-length-metadata fixture 2', solve(\"abc\",\"X\",\"identity\",0,0), [0,0,3])\ncheck('selected-length-metadata fixture 3', solve(\"abc\",\"X\",\"encoded\",0,0), [0,0,1])\ncheck('selected-length-metadata fixture 4', solve(\"xy\",\"XY\",\"encoded\",0,1), [0,1,2])\ncheck('selected-length-metadata fixture 5', solve(\"abcd\",\"XX\",\"encoded\",1,1), [1,1,2])\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":"67048bea65843b6666327c93dfd2086a3ffcb4fcc5deb7d1acde11a0756c6807","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(plain, encoded, coding, start, stop):\n    return [start,stop,len(plain)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('selected-length-metadata fixture 0', solve(\"abcdef\"*N,\"XYZ\"*N,\"encoded\",0,1), [0,1,3*N])\ncheck('selected-length-metadata fixture 1', solve(\"ab\",\"WXYZ\",\"identity\",0,1), [0,1,2])\ncheck('selected-length-metadata fixture 2', solve(\"abc\",\"X\",\"identity\",0,0), [0,0,3])\ncheck('selected-length-metadata fixture 3', solve(\"abc\",\"X\",\"encoded\",0,0), [0,0,1])\ncheck('selected-length-metadata fixture 4', solve(\"xy\",\"XY\",\"encoded\",0,1), [0,1,2])\ncheck('selected-length-metadata fixture 5', solve(\"abcd\",\"XX\",\"encoded\",1,1), [1,1,2])\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":"f4da6d7695bd452657bad74a78a969ea234c83c6b376b2cc645f30bba66248ed","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(plain, encoded, coding, start, stop):\n    return [start,stop,len(encoded if coding==\"encoded\" else plain)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('selected-length-metadata fixture 0', solve(\"abcdef\"*N,\"XYZ\"*N,\"encoded\",0,1), [0,1,3*N])\ncheck('selected-length-metadata fixture 1', solve(\"ab\",\"WXYZ\",\"identity\",0,1), [0,1,2])\ncheck('selected-length-metadata fixture 2', solve(\"abc\",\"X\",\"identity\",0,0), [0,0,3])\ncheck('selected-length-metadata fixture 3', solve(\"abc\",\"X\",\"encoded\",0,0), [0,0,1])\ncheck('selected-length-metadata fixture 4', solve(\"xy\",\"XY\",\"encoded\",0,1), [0,1,2])\ncheck('selected-length-metadata fixture 5', solve(\"abcd\",\"XX\",\"encoded\",1,1), [1,1,2])\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-selected-length-metadata","generated_at":"2026-09-29T14:41:15.678733+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 [start,stop,len(encoded if coding==\"encoded\" else plain)]","root_cause":"The selected-length-metadata decision uses return [start,stop,len(plain)].","sha256":"982dc45f89da5a1ff4fa6b2cc67e046631e284c80d691a98d6258f9eed810696","title":"Range metadata uses the negotiated variant length · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.11,"exit_code":1,"observations":[{"actual":[0,1,6],"check":"selected-length-metadata fixture 0","expected":[0,1,3],"passed":false},{"actual":[0,1,4],"check":"selected-length-metadata fixture 1","expected":[0,1,2],"passed":false},{"actual":[0,0,3],"check":"selected-length-metadata fixture 2","expected":[0,0,3],"passed":true},{"actual":[0,0,3],"check":"selected-length-metadata fixture 3","expected":[0,0,1],"passed":false},{"actual":[0,1,2],"check":"selected-length-metadata fixture 4","expected":[0,1,2],"passed":true},{"actual":[1,1,4],"check":"selected-length-metadata fixture 5","expected":[1,1,2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"selected-length-metadata fixture 0\", \"actual\": [0, 1, 6], \"expected\": [0, 1, 3], \"passed\": false}, {\"check\": \"selected-length-metadata fixture 1\", \"actual\": [0, 1, 4], \"expected\": [0, 1, 2], \"passed\": false}, {\"check\": \"selected-length-metadata fixture 2\", \"actual\": [0, 0, 3], \"expected\": [0, 0, 3], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 3\", \"actual\": [0, 0, 3], \"expected\": [0, 0, 1], \"passed\": false}, {\"check\": \"selected-length-metadata fixture 4\", \"actual\": [0, 1, 2], \"expected\": [0, 1, 2], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 5\", \"actual\": [1, 1, 4], \"expected\": [1, 1, 2], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.37,"exit_code":1,"observations":[{"actual":[0,1,6],"check":"selected-length-metadata fixture 0","expected":[0,1,3],"passed":false},{"actual":[0,1,2],"check":"selected-length-metadata fixture 1","expected":[0,1,2],"passed":true},{"actual":[0,0,3],"check":"selected-length-metadata fixture 2","expected":[0,0,3],"passed":true},{"actual":[0,0,3],"check":"selected-length-metadata fixture 3","expected":[0,0,1],"passed":false},{"actual":[0,1,2],"check":"selected-length-metadata fixture 4","expected":[0,1,2],"passed":true},{"actual":[1,1,4],"check":"selected-length-metadata fixture 5","expected":[1,1,2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"selected-length-metadata fixture 0\", \"actual\": [0, 1, 6], \"expected\": [0, 1, 3], \"passed\": false}, {\"check\": \"selected-length-metadata fixture 1\", \"actual\": [0, 1, 2], \"expected\": [0, 1, 2], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 2\", \"actual\": [0, 0, 3], \"expected\": [0, 0, 3], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 3\", \"actual\": [0, 0, 3], \"expected\": [0, 0, 1], \"passed\": false}, {\"check\": \"selected-length-metadata fixture 4\", \"actual\": [0, 1, 2], \"expected\": [0, 1, 2], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 5\", \"actual\": [1, 1, 4], \"expected\": [1, 1, 2], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.775,"exit_code":0,"observations":[{"actual":[0,1,3],"check":"selected-length-metadata fixture 0","expected":[0,1,3],"passed":true},{"actual":[0,1,2],"check":"selected-length-metadata fixture 1","expected":[0,1,2],"passed":true},{"actual":[0,0,3],"check":"selected-length-metadata fixture 2","expected":[0,0,3],"passed":true},{"actual":[0,0,1],"check":"selected-length-metadata fixture 3","expected":[0,0,1],"passed":true},{"actual":[0,1,2],"check":"selected-length-metadata fixture 4","expected":[0,1,2],"passed":true},{"actual":[1,1,2],"check":"selected-length-metadata fixture 5","expected":[1,1,2],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"selected-length-metadata fixture 0\", \"actual\": [0, 1, 3], \"expected\": [0, 1, 3], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 1\", \"actual\": [0, 1, 2], \"expected\": [0, 1, 2], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 2\", \"actual\": [0, 0, 3], \"expected\": [0, 0, 3], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 3\", \"actual\": [0, 0, 1], \"expected\": [0, 0, 1], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 4\", \"actual\": [0, 1, 2], \"expected\": [0, 1, 2], \"passed\": true}, {\"check\": \"selected-length-metadata fixture 5\", \"actual\": [1, 1, 2], \"expected\": [1, 1, 2], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}