{"abstract":"Out-of-order downloaded ranges write at their absolute positions.","category":"HTTP ranges","checks":6,"contract":"ASCII base is a preallocated buffer; offset and part fit within it. Replace that exact span without inserting or appending.","contract_signature":"base, offset, part","evaluation_group":"s3-http_ranges-resume-client","failed_approach":"The partial repair uses return base[:offset]+part+base[offset:], which still violates the stated contract.","family":"s3-http_ranges-resume-file-offset-write","id":"FA-26761","implementations":{"attempt":{"sha256":"495561ffb801590397b7ca33a8c7548fdcbeadfd430dac846820711061ed4c32","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(base, offset, part):\n    return base[:offset]+part+base[offset:]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-file-offset-write fixture 0', solve(\".\"*(N+3),N,\"AB\"), \".\"*N+\"AB.\")\ncheck('resume-file-offset-write fixture 1', solve(\"....\",0,\"AB\"), \"AB..\")\ncheck('resume-file-offset-write fixture 2', solve(\"....\",2,\"AB\"), \"..AB\")\ncheck('resume-file-offset-write fixture 3', solve(\"abc\",1,\"\"), \"abc\")\ncheck('resume-file-offset-write fixture 4', solve(\"abc\",0,\"XYZ\"), \"XYZ\")\ncheck('resume-file-offset-write fixture 5', solve(\"abc\",1,\"Z\"), \"aZc\")\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":"e9bf2e59d4601f530369cb86f70d8e63fd49defa5017ed1c305f35f865edae9e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(base, offset, part):\n    return base+part\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-file-offset-write fixture 0', solve(\".\"*(N+3),N,\"AB\"), \".\"*N+\"AB.\")\ncheck('resume-file-offset-write fixture 1', solve(\"....\",0,\"AB\"), \"AB..\")\ncheck('resume-file-offset-write fixture 2', solve(\"....\",2,\"AB\"), \"..AB\")\ncheck('resume-file-offset-write fixture 3', solve(\"abc\",1,\"\"), \"abc\")\ncheck('resume-file-offset-write fixture 4', solve(\"abc\",0,\"XYZ\"), \"XYZ\")\ncheck('resume-file-offset-write fixture 5', solve(\"abc\",1,\"Z\"), \"aZc\")\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-resume-file-offset-write","generated_at":"2026-09-29T14:41:18.809875+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 resume-file-offset-write decision uses return base+part.","sha256":"11d2bda24ed638910267a63c23e65c136e2aa8778b03c2b4c368c89c188c5f33","title":"Out-of-order downloaded ranges write at their absolute positions · 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":39.229,"exit_code":1,"observations":[{"actual":".AB...","check":"resume-file-offset-write fixture 0","expected":".AB.","passed":false},{"actual":"AB....","check":"resume-file-offset-write fixture 1","expected":"AB..","passed":false},{"actual":"..AB..","check":"resume-file-offset-write fixture 2","expected":"..AB","passed":false},{"actual":"abc","check":"resume-file-offset-write fixture 3","expected":"abc","passed":true},{"actual":"XYZabc","check":"resume-file-offset-write fixture 4","expected":"XYZ","passed":false},{"actual":"aZbc","check":"resume-file-offset-write fixture 5","expected":"aZc","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-file-offset-write fixture 0\", \"actual\": \".AB...\", \"expected\": \".AB.\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 1\", \"actual\": \"AB....\", \"expected\": \"AB..\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 2\", \"actual\": \"..AB..\", \"expected\": \"..AB\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 3\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"resume-file-offset-write fixture 4\", \"actual\": \"XYZabc\", \"expected\": \"XYZ\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 5\", \"actual\": \"aZbc\", \"expected\": \"aZc\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.995,"exit_code":1,"observations":[{"actual":"....AB","check":"resume-file-offset-write fixture 0","expected":".AB.","passed":false},{"actual":"....AB","check":"resume-file-offset-write fixture 1","expected":"AB..","passed":false},{"actual":"....AB","check":"resume-file-offset-write fixture 2","expected":"..AB","passed":false},{"actual":"abc","check":"resume-file-offset-write fixture 3","expected":"abc","passed":true},{"actual":"abcXYZ","check":"resume-file-offset-write fixture 4","expected":"XYZ","passed":false},{"actual":"abcZ","check":"resume-file-offset-write fixture 5","expected":"aZc","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-file-offset-write fixture 0\", \"actual\": \"....AB\", \"expected\": \".AB.\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 1\", \"actual\": \"....AB\", \"expected\": \"AB..\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 2\", \"actual\": \"....AB\", \"expected\": \"..AB\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 3\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"resume-file-offset-write fixture 4\", \"actual\": \"abcXYZ\", \"expected\": \"XYZ\", \"passed\": false}, {\"check\": \"resume-file-offset-write fixture 5\", \"actual\": \"abcZ\", \"expected\": \"aZc\", \"passed\": false}], \"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."}}