{"abstract":"Content coding decode order reverses application order.","category":"Content negotiation","checks":4,"contract":"Bounded offline decision model: content coding decode order reverses application order. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-content-coding-decode-order-reverses-application-order","failed_approach":"The attempted repair uses `sorted(codings)` and still violates a separate fixture.","family":"xh-content-coding-decode-order-reverses-application-order","id":"FA-6946","implementations":{"attempt":{"sha256":"a94166d0b4c2ee5b43c41be7361c12be1ff3a9163787ebfb7f005a900e48c342","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(codings):\n    return sorted(codings)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(['gzip', 'br']), ['br', 'gzip'])\", \"check('fixture 2', solve(['br', 'gzip']), ['gzip', 'br'])\", \"check('fixture 3', solve([]), [])\", \"check('fixture 4', solve(['gzip']), ['gzip'])\"]\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":"8036d4fafbcbaa049e34ea64ce00ba0578ef98ca0a712006b44357be35cf1b62","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(codings):\n    return codings\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(['gzip', 'br']), ['br', 'gzip'])\", \"check('fixture 2', solve(['br', 'gzip']), ['gzip', 'br'])\", \"check('fixture 3', solve([]), [])\", \"check('fixture 4', solve(['gzip']), ['gzip'])\"]\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":"84fb706bb36ed6073ccaddf32ce4f255ca9fd56eed54470c38c2ddcffa96af5d","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(codings):\n    return list(reversed(codings))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(['gzip', 'br']), ['br', 'gzip'])\", \"check('fixture 2', solve(['br', 'gzip']), ['gzip', 'br'])\", \"check('fixture 3', solve([]), [])\", \"check('fixture 4', solve(['gzip']), ['gzip'])\"]\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-content-coding-decode-order-reverses-application-order","generated_at":"2026-09-29T14:38:06.905527+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic content negotiation model isolates the content-coding-decode-order-reverses-application-order policy at a network component boundary.","repair":"Apply the explicit content-coding-decode-order-reverses-application-order contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `codings` for the content-coding-decode-order-reverses-application-order decision.","sha256":"1628b24cee544c03c64fd4302fd145f6dbf4c811a7d8995c5de6607627d14579","title":"Content coding decode order reverses application order · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":37.971,"exit_code":1,"observations":[{"actual":["br","gzip"],"check":"fixture 2","expected":["gzip","br"],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":["gzip"],"check":"fixture 4","expected":["gzip"],"passed":true},{"actual":["br","gzip"],"check":"fixture 1","expected":["br","gzip"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"br\", \"gzip\"], \"expected\": [\"gzip\", \"br\"], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"gzip\"], \"expected\": [\"gzip\"], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"br\", \"gzip\"], \"expected\": [\"br\", \"gzip\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":35.39,"exit_code":1,"observations":[{"actual":["br","gzip"],"check":"fixture 2","expected":["gzip","br"],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":["gzip"],"check":"fixture 4","expected":["gzip"],"passed":true},{"actual":["gzip","br"],"check":"fixture 1","expected":["br","gzip"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"br\", \"gzip\"], \"expected\": [\"gzip\", \"br\"], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"gzip\"], \"expected\": [\"gzip\"], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"gzip\", \"br\"], \"expected\": [\"br\", \"gzip\"], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":33.426,"exit_code":0,"observations":[{"actual":["gzip","br"],"check":"fixture 2","expected":["gzip","br"],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":["gzip"],"check":"fixture 4","expected":["gzip"],"passed":true},{"actual":["br","gzip"],"check":"fixture 1","expected":["br","gzip"],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"gzip\", \"br\"], \"expected\": [\"gzip\", \"br\"], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"gzip\"], \"expected\": [\"gzip\"], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"br\", \"gzip\"], \"expected\": [\"br\", \"gzip\"], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}