{"abstract":"Continue is emitted only before an expected request body.","category":"HTTP semantics","checks":4,"contract":"Continue is emitted only before an expected request body: return the result specified by the explicit input/output boundary fixtures.","contract_signature":"version, expect, remaining","evaluation_group":"xh-expect-continue","failed_approach":"The attempted repair uses `version == '1.1' and remaining > 0` and still violates a separate fixture.","family":"xh-expect-continue","id":"FA-6616","implementations":{"attempt":{"sha256":"204a2bc8b3ce8da607995ba6191d911036ce8d6e6550d2dea81aeabe4f7800e2","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(version, expect, remaining):\n    return version == '1.1' and remaining > 0\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('1.1', '100-Continue', 2), True)\", \"check('fixture 2', solve('1.1', '100-continue', 0), False)\", \"check('fixture 3', solve('1.0', '100-continue', 2), False)\", \"check('fixture 4', solve('1.1', '', 2), False)\"]\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":"b972c41d16e3c64a673fa3ea6c0117f27dddd69d254a5c0abff99a39fef7a0f3","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(version, expect, remaining):\n    return expect == '100-continue'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('1.1', '100-Continue', 2), True)\", \"check('fixture 2', solve('1.1', '100-continue', 0), False)\", \"check('fixture 3', solve('1.0', '100-continue', 2), False)\", \"check('fixture 4', solve('1.1', '', 2), False)\"]\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-expect-continue","generated_at":"2026-09-29T14:38:03.749972+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic http semantics model isolates the expect-continue policy at a network component boundary.","root_cause":"The faulty implementation uses `expect == '100-continue'` for the expect-continue decision.","sha256":"87681ba01b18b9829a9468a9b82db46650d6f428ffac9d7f0837d7e8e2be7903","title":"Continue is emitted only before an expected request body · 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":37.105,"exit_code":1,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":false,"check":"fixture 3","expected":false,"passed":true},{"actual":true,"check":"fixture 4","expected":false,"passed":false},{"actual":true,"check":"fixture 1","expected":true,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":34.946,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":false,"passed":false},{"actual":true,"check":"fixture 3","expected":false,"passed":false},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":false,"check":"fixture 1","expected":true,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": true, \"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."}}