{"abstract":"Http2 settings ack must have empty payload.","category":"Multiplexed protocols","checks":4,"contract":"Bounded offline decision model: http2 settings ack must have empty payload. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"ack, payload_size","evaluation_group":"xh-http2-settings-ack-must-have-empty-payload","failed_approach":"The attempted repair uses `not ack or payload_size % 6 == 0` and still violates a separate fixture.","family":"xh-http2-settings-ack-must-have-empty-payload","id":"FA-7496","implementations":{"attempt":{"sha256":"cd5fdf9e591b4a016b428313ffe986a98f0725f24b1600a8f4a6d8ca681b0875","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(ack, payload_size):\n    return not ack or payload_size % 6 == 0\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(True, 6), False)\", \"check('fixture 2', solve(False, 6), True)\", \"check('fixture 3', solve(True, 0), True)\", \"check('fixture 4', solve(False, 0), True)\"]\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":"4a1ae3c79108979e6d4318efcc662457116c5f5364872628988f8946fdc01c5a","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(ack, payload_size):\n    return payload_size == 0\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(True, 6), False)\", \"check('fixture 2', solve(False, 6), True)\", \"check('fixture 3', solve(True, 0), True)\", \"check('fixture 4', solve(False, 0), True)\"]\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-http2-settings-ack-must-have-empty-payload","generated_at":"2026-09-29T14:38:12.636343+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic multiplexed protocols model isolates the http2-settings-ack-must-have-empty-payload policy at a network component boundary.","root_cause":"The faulty implementation uses `payload_size == 0` for the http2-settings-ack-must-have-empty-payload decision.","sha256":"bffd1e4c47ffd65053c3d306e9634402c183df7687c57e63319f113900c12626","title":"Http2 settings ack must have empty payload · 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":42.489,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":true,"passed":true},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":true,"check":"fixture 4","expected":true,"passed":true},{"actual":true,"check":"fixture 1","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": false, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.574,"exit_code":1,"observations":[{"actual":false,"check":"fixture 2","expected":true,"passed":false},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":true,"check":"fixture 4","expected":true,"passed":true},{"actual":false,"check":"fixture 1","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": true, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": false, \"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."}}