{"abstract":"Response boundary for fixed length body detects short eof.","category":"Connection lifecycle","checks":4,"contract":"Bounded offline decision model: response boundary for fixed length body detects short eof. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-response-boundary-for-fixed-length-body-detects-short-eof","failed_approach":"The attempted repair uses `'complete' if received >= expected else 'wait'` and still violates a separate fixture.","family":"xh-response-boundary-for-fixed-length-body-detects-short-eof","id":"FA-7806","implementations":{"attempt":{"sha256":"e981b10323d22143fa84ad7d487118a9d783f0ebdc1e31c74d4345bdc148134a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(expected, received, eof):\n    return 'complete' if received >= expected else 'wait'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(10, 5, True), 'truncated')\", \"check('fixture 2', solve(10, 10, False), 'complete')\", \"check('fixture 3', solve(10, 5, False), 'wait')\", \"check('fixture 4', solve(0, 0, True), 'complete')\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"6bca84df4493710f5c98de2df2707291af128ff4622567dc2136b3fd05d0e5ec","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(expected, received, eof):\n    return 'complete' if eof or received >= expected else 'wait'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(10, 5, True), 'truncated')\", \"check('fixture 2', solve(10, 10, False), 'complete')\", \"check('fixture 3', solve(10, 5, False), 'wait')\", \"check('fixture 4', solve(0, 0, True), 'complete')\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"e76df776f9008229f7c1f1cfbd30f61688026735f6641ed48d99835ace3970b9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(expected, received, eof):\n    return 'truncated' if eof and received < expected else ('complete' if received >= expected else 'wait')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(10, 5, True), 'truncated')\", \"check('fixture 2', solve(10, 10, False), 'complete')\", \"check('fixture 3', solve(10, 5, False), 'wait')\", \"check('fixture 4', solve(0, 0, True), 'complete')\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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":"xh-response-boundary-for-fixed-length-body-detects-short-eof","generated_at":"2026-09-29T14:38:15.487319+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic connection lifecycle model isolates the response-boundary-for-fixed-length-body-detects-short-eof policy at a network component boundary.","repair":"Apply the explicit response-boundary-for-fixed-length-body-detects-short-eof contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `'complete' if eof or received >= expected else 'wait'` for the response-boundary-for-fixed-length-body-detects-short-eof decision.","sha256":"c0a139bb2c5bff38900e93372ecfcd736d6c9bbb6da00a62b717378e55494b43","title":"Response boundary for fixed length body detects short eof · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.177,"exit_code":1,"observations":[{"actual":"complete","check":"fixture 2","expected":"complete","passed":true},{"actual":"wait","check":"fixture 3","expected":"wait","passed":true},{"actual":"complete","check":"fixture 4","expected":"complete","passed":true},{"actual":"wait","check":"fixture 1","expected":"truncated","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"complete\", \"expected\": \"complete\", \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": \"wait\", \"expected\": \"wait\", \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": \"complete\", \"expected\": \"complete\", \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": \"wait\", \"expected\": \"truncated\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.858,"exit_code":1,"observations":[{"actual":"complete","check":"fixture 2","expected":"complete","passed":true},{"actual":"wait","check":"fixture 3","expected":"wait","passed":true},{"actual":"complete","check":"fixture 4","expected":"complete","passed":true},{"actual":"complete","check":"fixture 1","expected":"truncated","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"complete\", \"expected\": \"complete\", \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": \"wait\", \"expected\": \"wait\", \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": \"complete\", \"expected\": \"complete\", \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": \"complete\", \"expected\": \"truncated\", \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":42.364,"exit_code":0,"observations":[{"actual":"complete","check":"fixture 2","expected":"complete","passed":true},{"actual":"wait","check":"fixture 3","expected":"wait","passed":true},{"actual":"complete","check":"fixture 4","expected":"complete","passed":true},{"actual":"truncated","check":"fixture 1","expected":"truncated","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"complete\", \"expected\": \"complete\", \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": \"wait\", \"expected\": \"wait\", \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": \"complete\", \"expected\": \"complete\", \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": \"truncated\", \"expected\": \"truncated\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}