{"abstract":"Dns referral needs authority ns records without terminal answer.","category":"DNS resolution","checks":4,"contract":"Bounded offline decision model: dns referral needs authority ns records without terminal answer. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-dns-referral-needs-authority-ns-records-without-terminal-answer","failed_approach":"The attempted repair uses `not answer and bool(ns)` and still violates a separate fixture.","family":"xh-dns-referral-needs-authority-ns-records-without-terminal-answer","id":"FA-7401","implementations":{"attempt":{"sha256":"6c9d3a7b197b309d96e854bae2e06c95e50c470c7b921469bb7ad094f7f1036f","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(answer, ns, authoritative):\n    return not answer and bool(ns)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve([], ['ns'], False), True)\", \"check('fixture 2', solve(['a'], ['ns'], False), False)\", \"check('fixture 3', solve([], ['ns'], True), False)\", \"check('fixture 4', solve([], [], 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":"39b53a9904012ff2266214e55d4dcad3810370a332bdf444188b297f69a95541","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(answer, ns, authoritative):\n    return bool(ns)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve([], ['ns'], False), True)\", \"check('fixture 2', solve(['a'], ['ns'], False), False)\", \"check('fixture 3', solve([], ['ns'], True), False)\", \"check('fixture 4', solve([], [], 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":"a5d010c11791fe889baa71a4e3af63c97a5b3446351c1700c21e6fce91616909","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(answer, ns, authoritative):\n    return not answer and bool(ns) and not authoritative\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve([], ['ns'], False), True)\", \"check('fixture 2', solve(['a'], ['ns'], False), False)\", \"check('fixture 3', solve([], ['ns'], True), False)\", \"check('fixture 4', solve([], [], 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-referral-needs-authority-ns-records-without-terminal-answer","generated_at":"2026-09-29T14:38:11.504173+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic dns resolution model isolates the dns-referral-needs-authority-ns-records-without-terminal-answer policy at a network component boundary.","repair":"Apply the explicit dns-referral-needs-authority-ns-records-without-terminal-answer contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `bool(ns)` for the dns-referral-needs-authority-ns-records-without-terminal-answer decision.","sha256":"6bcc631f92d2db12a817c37cb36a9402980a4eb52a9e98db896a3deab80066a5","title":"Dns referral needs authority ns records without terminal answer · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":49.002,"exit_code":1,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":true,"check":"fixture 3","expected":false,"passed":false},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"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\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":52.854,"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":true,"check":"fixture 1","expected":true,"passed":true}],"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\": true, \"expected\": true, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":44.633,"exit_code":0,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":false,"check":"fixture 3","expected":false,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":true,"check":"fixture 1","expected":true,"passed":true}],"passed":true,"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\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}