{"abstract":"A full fallback response replaces an existing download prefix.","category":"HTTP ranges","checks":6,"contract":"For status200 replace prefix with full body; for206 append already validated continuation body. Other statuses preserve prefix.","contract_signature":"status, prefix, body","evaluation_group":"s3-http_ranges-resume-client","failed_approach":"The partial repair uses return body if status==200 else prefix+body, which still violates the stated contract.","family":"s3-http_ranges-resume-full-response-truncate","id":"FA-26741","implementations":{"attempt":{"sha256":"98932674584cedfa65991c63a9bf32307cb7636fd91c37fb3b717612f0ab39e7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(status, prefix, body):\n    return body if status==200 else prefix+body\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-full-response-truncate fixture 0', solve(200,\"old\"*N,\"new\"*N), \"new\"*N)\ncheck('resume-full-response-truncate fixture 1', solve(416,\"old\",\"error\"), \"old\")\ncheck('resume-full-response-truncate fixture 2', solve(206,\"a\"*N,\"b\"*N), \"a\"*N+\"b\"*N)\ncheck('resume-full-response-truncate fixture 3', solve(200,\"old\",\"\"), \"\")\ncheck('resume-full-response-truncate fixture 4', solve(500,\"old\",\"error\"), \"old\")\ncheck('resume-full-response-truncate fixture 5', solve(206,\"\",\"x\"), \"x\")\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":"4bca5d2eff927ecd6d23aad2c8c2f3c4095c97d7e0cb2cf75fe622b5203be646","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(status, prefix, body):\n    return prefix+body\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-full-response-truncate fixture 0', solve(200,\"old\"*N,\"new\"*N), \"new\"*N)\ncheck('resume-full-response-truncate fixture 1', solve(416,\"old\",\"error\"), \"old\")\ncheck('resume-full-response-truncate fixture 2', solve(206,\"a\"*N,\"b\"*N), \"a\"*N+\"b\"*N)\ncheck('resume-full-response-truncate fixture 3', solve(200,\"old\",\"\"), \"\")\ncheck('resume-full-response-truncate fixture 4', solve(500,\"old\",\"error\"), \"old\")\ncheck('resume-full-response-truncate fixture 5', solve(206,\"\",\"x\"), \"x\")\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-full-response-truncate","generated_at":"2026-09-29T14:41:18.750918+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-full-response-truncate decision uses return prefix+body.","sha256":"d21e5e731995344a760aa5a9b1e17beef1fd3ba72202de40cace9b2deca7a59a","title":"A full fallback response replaces an existing download prefix · 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":40.394,"exit_code":1,"observations":[{"actual":"new","check":"resume-full-response-truncate fixture 0","expected":"new","passed":true},{"actual":"olderror","check":"resume-full-response-truncate fixture 1","expected":"old","passed":false},{"actual":"ab","check":"resume-full-response-truncate fixture 2","expected":"ab","passed":true},{"actual":"","check":"resume-full-response-truncate fixture 3","expected":"","passed":true},{"actual":"olderror","check":"resume-full-response-truncate fixture 4","expected":"old","passed":false},{"actual":"x","check":"resume-full-response-truncate fixture 5","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-full-response-truncate fixture 0\", \"actual\": \"new\", \"expected\": \"new\", \"passed\": true}, {\"check\": \"resume-full-response-truncate fixture 1\", \"actual\": \"olderror\", \"expected\": \"old\", \"passed\": false}, {\"check\": \"resume-full-response-truncate fixture 2\", \"actual\": \"ab\", \"expected\": \"ab\", \"passed\": true}, {\"check\": \"resume-full-response-truncate fixture 3\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"resume-full-response-truncate fixture 4\", \"actual\": \"olderror\", \"expected\": \"old\", \"passed\": false}, {\"check\": \"resume-full-response-truncate fixture 5\", \"actual\": \"x\", \"expected\": \"x\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.754,"exit_code":1,"observations":[{"actual":"oldnew","check":"resume-full-response-truncate fixture 0","expected":"new","passed":false},{"actual":"olderror","check":"resume-full-response-truncate fixture 1","expected":"old","passed":false},{"actual":"ab","check":"resume-full-response-truncate fixture 2","expected":"ab","passed":true},{"actual":"old","check":"resume-full-response-truncate fixture 3","expected":"","passed":false},{"actual":"olderror","check":"resume-full-response-truncate fixture 4","expected":"old","passed":false},{"actual":"x","check":"resume-full-response-truncate fixture 5","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-full-response-truncate fixture 0\", \"actual\": \"oldnew\", \"expected\": \"new\", \"passed\": false}, {\"check\": \"resume-full-response-truncate fixture 1\", \"actual\": \"olderror\", \"expected\": \"old\", \"passed\": false}, {\"check\": \"resume-full-response-truncate fixture 2\", \"actual\": \"ab\", \"expected\": \"ab\", \"passed\": true}, {\"check\": \"resume-full-response-truncate fixture 3\", \"actual\": \"old\", \"expected\": \"\", \"passed\": false}, {\"check\": \"resume-full-response-truncate fixture 4\", \"actual\": \"olderror\", \"expected\": \"old\", \"passed\": false}, {\"check\": \"resume-full-response-truncate fixture 5\", \"actual\": \"x\", \"expected\": \"x\", \"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."}}