{"abstract":"Negotiated content type retains selected parameters.","category":"Content negotiation","checks":4,"contract":"Bounded offline decision model: negotiated content type retains selected parameters. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"type_, parameters","evaluation_group":"xh-negotiated-content-type-retains-selected-parameters","failed_approach":"The attempted repair uses `type_ + \"; \" + \"; \".join(k+\"=\"+v for k,v in parameters)` and still violates a separate fixture.","family":"xh-negotiated-content-type-retains-selected-parameters","id":"FA-6926","implementations":{"attempt":{"sha256":"b8797d468c1a96604bb33ba7bdca7ee9eb92945a8fafb62693e8528fdcbf2a13","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(type_, parameters):\n    return type_ + \"; \" + \"; \".join(k+\"=\"+v for k,v in parameters)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('text/plain', [('charset', 'utf-8')]), 'text/plain; charset=utf-8')\", \"check('fixture 2', solve('image/png', []), 'image/png')\", \"check('fixture 3', solve('text/html', [('level', '1'), ('charset', 'utf-8')]), 'text/html; level=1; charset=utf-8')\", \"check('fixture 4', solve('application/json', []), 'application/json')\"]\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":"6c2e2b05e9a863e0c5d0243a1bf515abe104f5a79439ccc158c79657130a3de4","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(type_, parameters):\n    return type_\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('text/plain', [('charset', 'utf-8')]), 'text/plain; charset=utf-8')\", \"check('fixture 2', solve('image/png', []), 'image/png')\", \"check('fixture 3', solve('text/html', [('level', '1'), ('charset', 'utf-8')]), 'text/html; level=1; charset=utf-8')\", \"check('fixture 4', solve('application/json', []), 'application/json')\"]\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-negotiated-content-type-retains-selected-parameters","generated_at":"2026-09-29T14:38:06.699375+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic content negotiation model isolates the negotiated-content-type-retains-selected-parameters policy at a network component boundary.","root_cause":"The faulty implementation uses `type_` for the negotiated-content-type-retains-selected-parameters decision.","sha256":"3d6be5f4b529d38b0240cb75b51c0766626f36a16f393e2f4f80b73e9fe2e17d","title":"Negotiated content type retains selected parameters · 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":37.364,"exit_code":1,"observations":[{"actual":"image/png; ","check":"fixture 2","expected":"image/png","passed":false},{"actual":"text/html; level=1; charset=utf-8","check":"fixture 3","expected":"text/html; level=1; charset=utf-8","passed":true},{"actual":"application/json; ","check":"fixture 4","expected":"application/json","passed":false},{"actual":"text/plain; charset=utf-8","check":"fixture 1","expected":"text/plain; charset=utf-8","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"image/png; \", \"expected\": \"image/png\", \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": \"text/html; level=1; charset=utf-8\", \"expected\": \"text/html; level=1; charset=utf-8\", \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": \"application/json; \", \"expected\": \"application/json\", \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": \"text/plain; charset=utf-8\", \"expected\": \"text/plain; charset=utf-8\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":36.576,"exit_code":1,"observations":[{"actual":"image/png","check":"fixture 2","expected":"image/png","passed":true},{"actual":"text/html","check":"fixture 3","expected":"text/html; level=1; charset=utf-8","passed":false},{"actual":"application/json","check":"fixture 4","expected":"application/json","passed":true},{"actual":"text/plain","check":"fixture 1","expected":"text/plain; charset=utf-8","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"image/png\", \"expected\": \"image/png\", \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": \"text/html\", \"expected\": \"text/html; level=1; charset=utf-8\", \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": \"application/json\", \"expected\": \"application/json\", \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": \"text/plain\", \"expected\": \"text/plain; charset=utf-8\", \"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."}}