{"abstract":"End-of-stream without a closing delimiter leaves the response incomplete.","category":"HTTP ranges","checks":6,"contract":"Return [complete,parts] only after closing delimiter; EOF without close is [truncated,empty], otherwise [waiting,parts].","contract_signature":"parts, close_seen, eof","evaluation_group":"s3-http_ranges-multipart-client","failed_approach":"The partial repair uses return [\"complete\",parts] if close_seen else [\"waiting\",parts], which still violates the stated contract.","family":"s3-http_ranges-multipart-client-close-required","id":"FA-26821","implementations":{"attempt":{"sha256":"f37961dfe6787702e82a177e71436ab13366086b374d2d873584fc5b43381952","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts, close_seen, eof):\n    return [\"complete\",parts] if close_seen else [\"waiting\",parts]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-client-close-required fixture 0', solve( [\"p\"*N],False,True), [\"truncated\",[]])\ncheck('multipart-client-close-required fixture 1', solve([\"p\"],True,False), [\"complete\",[\"p\"]])\ncheck('multipart-client-close-required fixture 2', solve([\"p\"],False,False), [\"waiting\",[\"p\"]])\ncheck('multipart-client-close-required fixture 3', solve([],True,True), [\"complete\",[]])\ncheck('multipart-client-close-required fixture 4', solve([],False,True), [\"truncated\",[]])\ncheck('multipart-client-close-required fixture 5', solve([\"a\",\"b\"],True,True), [\"complete\",[\"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":"57250bc745e9276fffadef8ce8a7f589b507ac53d26b3f90817169592a5be2c1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(parts, close_seen, eof):\n    return [\"complete\",parts] if eof else [\"waiting\",parts]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('multipart-client-close-required fixture 0', solve( [\"p\"*N],False,True), [\"truncated\",[]])\ncheck('multipart-client-close-required fixture 1', solve([\"p\"],True,False), [\"complete\",[\"p\"]])\ncheck('multipart-client-close-required fixture 2', solve([\"p\"],False,False), [\"waiting\",[\"p\"]])\ncheck('multipart-client-close-required fixture 3', solve([],True,True), [\"complete\",[]])\ncheck('multipart-client-close-required fixture 4', solve([],False,True), [\"truncated\",[]])\ncheck('multipart-client-close-required fixture 5', solve([\"a\",\"b\"],True,True), [\"complete\",[\"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-close-required","generated_at":"2026-09-29T14:41:19.405841+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-close-required decision uses return [\"complete\",parts] if eof else [\"waiting\",parts].","sha256":"9de83f7b335ee642f9b52d48db28da5c302d0615dd86b5ad3b2359e72189dc07","title":"End-of-stream without a closing delimiter leaves the response incomplete · 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":40.407,"exit_code":1,"observations":[{"actual":["waiting",["p"]],"check":"multipart-client-close-required fixture 0","expected":["truncated",[]],"passed":false},{"actual":["complete",["p"]],"check":"multipart-client-close-required fixture 1","expected":["complete",["p"]],"passed":true},{"actual":["waiting",["p"]],"check":"multipart-client-close-required fixture 2","expected":["waiting",["p"]],"passed":true},{"actual":["complete",[]],"check":"multipart-client-close-required fixture 3","expected":["complete",[]],"passed":true},{"actual":["waiting",[]],"check":"multipart-client-close-required fixture 4","expected":["truncated",[]],"passed":false},{"actual":["complete",["a","b"]],"check":"multipart-client-close-required fixture 5","expected":["complete",["a","b"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-client-close-required fixture 0\", \"actual\": [\"waiting\", [\"p\"]], \"expected\": [\"truncated\", []], \"passed\": false}, {\"check\": \"multipart-client-close-required fixture 1\", \"actual\": [\"complete\", [\"p\"]], \"expected\": [\"complete\", [\"p\"]], \"passed\": true}, {\"check\": \"multipart-client-close-required fixture 2\", \"actual\": [\"waiting\", [\"p\"]], \"expected\": [\"waiting\", [\"p\"]], \"passed\": true}, {\"check\": \"multipart-client-close-required fixture 3\", \"actual\": [\"complete\", []], \"expected\": [\"complete\", []], \"passed\": true}, {\"check\": \"multipart-client-close-required fixture 4\", \"actual\": [\"waiting\", []], \"expected\": [\"truncated\", []], \"passed\": false}, {\"check\": \"multipart-client-close-required fixture 5\", \"actual\": [\"complete\", [\"a\", \"b\"]], \"expected\": [\"complete\", [\"a\", \"b\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.204,"exit_code":1,"observations":[{"actual":["complete",["p"]],"check":"multipart-client-close-required fixture 0","expected":["truncated",[]],"passed":false},{"actual":["waiting",["p"]],"check":"multipart-client-close-required fixture 1","expected":["complete",["p"]],"passed":false},{"actual":["waiting",["p"]],"check":"multipart-client-close-required fixture 2","expected":["waiting",["p"]],"passed":true},{"actual":["complete",[]],"check":"multipart-client-close-required fixture 3","expected":["complete",[]],"passed":true},{"actual":["complete",[]],"check":"multipart-client-close-required fixture 4","expected":["truncated",[]],"passed":false},{"actual":["complete",["a","b"]],"check":"multipart-client-close-required fixture 5","expected":["complete",["a","b"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"multipart-client-close-required fixture 0\", \"actual\": [\"complete\", [\"p\"]], \"expected\": [\"truncated\", []], \"passed\": false}, {\"check\": \"multipart-client-close-required fixture 1\", \"actual\": [\"waiting\", [\"p\"]], \"expected\": [\"complete\", [\"p\"]], \"passed\": false}, {\"check\": \"multipart-client-close-required fixture 2\", \"actual\": [\"waiting\", [\"p\"]], \"expected\": [\"waiting\", [\"p\"]], \"passed\": true}, {\"check\": \"multipart-client-close-required fixture 3\", \"actual\": [\"complete\", []], \"expected\": [\"complete\", []], \"passed\": true}, {\"check\": \"multipart-client-close-required fixture 4\", \"actual\": [\"complete\", []], \"expected\": [\"truncated\", []], \"passed\": false}, {\"check\": \"multipart-client-close-required fixture 5\", \"actual\": [\"complete\", [\"a\", \"b\"]], \"expected\": [\"complete\", [\"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."}}