{"abstract":"Dns response qr bit must mark response.","category":"DNS resolution","checks":4,"contract":"Bounded offline decision model: dns response qr bit must mark response. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-dns-response-qr-bit-must-mark-response","failed_approach":"The attempted repair uses `qr` and still violates a separate fixture.","family":"xh-dns-response-qr-bit-must-mark-response","id":"FA-7436","implementations":{"attempt":{"sha256":"d9383facce397fc5146e9089a6874457d470d9f579ac865f4124a6c9d18e9c1c","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(qr, identifier_ok):\n    return qr\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(False, True), False)\", \"check('fixture 2', solve(True, False), False)\", \"check('fixture 3', solve(True, True), True)\", \"check('fixture 4', solve(False, False), 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":"5f2a0deb153c2d1c136b4a04ce488a45680e8a6b2278c016eca004ca235c71e8","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(qr, identifier_ok):\n    return identifier_ok\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(False, True), False)\", \"check('fixture 2', solve(True, False), False)\", \"check('fixture 3', solve(True, True), True)\", \"check('fixture 4', solve(False, False), 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"},"fixed":{"sha256":"22c4e4438a709413db058145978735f9827f0a289ada6d89d4861e777d640624","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(qr, identifier_ok):\n    return qr and identifier_ok\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(False, True), False)\", \"check('fixture 2', solve(True, False), False)\", \"check('fixture 3', solve(True, True), True)\", \"check('fixture 4', solve(False, False), 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-dns-response-qr-bit-must-mark-response","generated_at":"2026-09-29T14:38:12.033050+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic dns resolution model isolates the dns-response-qr-bit-must-mark-response policy at a network component boundary.","repair":"Apply the explicit dns-response-qr-bit-must-mark-response contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `identifier_ok` for the dns-response-qr-bit-must-mark-response decision.","sha256":"a213351a47a81e8a8c04fc876d29b0022c8725bda54a2cc03602da1a4bb362be","title":"Dns response qr bit must mark response · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":54.449,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":false,"passed":false},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":false,"check":"fixture 1","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":49.113,"exit_code":1,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":true,"check":"fixture 1","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": false, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":51.706,"exit_code":0,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":false,"check":"fixture 1","expected":false,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}