{"abstract":"Dns additional records do not override authoritative answers.","category":"DNS resolution","checks":4,"contract":"Given answers, additional, allowed, dns additional records do not override authoritative answers. Return the protocol decision or transformed value; fields are validated and fixtures state boundary outcomes.","contract_signature":"answers, additional, allowed","evaluation_group":"xh-dns-additional-records-do-not-override-authoritative-answers","failed_approach":"The attempted repair uses `dict({k:v for k,v in answers.items() if k in allowed},**additional)` and still violates a separate fixture.","family":"xh-dns-additional-records-do-not-override-authoritative-answers","id":"FA-7396","implementations":{"attempt":{"sha256":"0c0681eceb0724e5ea5316b3a99b82ffd2ae01d36d3d09c1e3b0a22577553481","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(answers, additional, allowed):\n    return dict({k:v for k,v in answers.items() if k in allowed},**additional)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve({'a': 1}, {'a': 2, 'evil': 3}, ['a']), {'a': 1})\", \"check('fixture 2', solve({}, {'a': 2, 'evil': 3}, ['a']), {'a': 2})\", \"check('fixture 3', solve({'a': 1}, {}, []), {'a': 1})\", \"check('fixture 4', solve({}, {}, []), {})\"]\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":"0e18a464290ab4be03196f2742872454b1a8c18ee5008efbfea1a6d1ea1700d7","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(answers, additional, allowed):\n    return dict(answers,**additional)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve({'a': 1}, {'a': 2, 'evil': 3}, ['a']), {'a': 1})\", \"check('fixture 2', solve({}, {'a': 2, 'evil': 3}, ['a']), {'a': 2})\", \"check('fixture 3', solve({'a': 1}, {}, []), {'a': 1})\", \"check('fixture 4', solve({}, {}, []), {})\"]\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-additional-records-do-not-override-authoritative-answers","generated_at":"2026-09-29T14:38:11.506573+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic dns resolution model isolates the dns-additional-records-do-not-override-authoritative-answers policy at a network component boundary.","root_cause":"The faulty implementation uses `dict(answers,**additional)` for the dns-additional-records-do-not-override-authoritative-answers decision.","sha256":"57949fa9f79357444704711ff8204a1ee5f9e625932a55bd6423254477005d71","title":"Dns additional records do not override authoritative answers · 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":52.257,"exit_code":1,"observations":[{"actual":{"a":2,"evil":3},"check":"fixture 2","expected":{"a":2},"passed":false},{"actual":{},"check":"fixture 3","expected":{"a":1},"passed":false},{"actual":{},"check":"fixture 4","expected":{},"passed":true},{"actual":{"a":2,"evil":3},"check":"fixture 1","expected":{"a":1},"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": {\"a\": 2, \"evil\": 3}, \"expected\": {\"a\": 2}, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": {}, \"expected\": {\"a\": 1}, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": {\"a\": 2, \"evil\": 3}, \"expected\": {\"a\": 1}, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":56.096,"exit_code":1,"observations":[{"actual":{"a":2,"evil":3},"check":"fixture 2","expected":{"a":2},"passed":false},{"actual":{"a":1},"check":"fixture 3","expected":{"a":1},"passed":true},{"actual":{},"check":"fixture 4","expected":{},"passed":true},{"actual":{"a":2,"evil":3},"check":"fixture 1","expected":{"a":1},"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": {\"a\": 2, \"evil\": 3}, \"expected\": {\"a\": 2}, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": {\"a\": 1}, \"expected\": {\"a\": 1}, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": {\"a\": 2, \"evil\": 3}, \"expected\": {\"a\": 1}, \"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."}}