{"abstract":"Multiple set cookie fields are not comma coalesced.","category":"Proxy forwarding","checks":4,"contract":"Bounded offline decision model: multiple set cookie fields are not comma coalesced. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-multiple-set-cookie-fields-are-not-comma-coalesced","failed_approach":"The attempted repair uses `list(dict.fromkeys(fields))` and still violates a separate fixture.","family":"xh-multiple-set-cookie-fields-are-not-comma-coalesced","id":"FA-7006","implementations":{"attempt":{"sha256":"402532726870dc15fa8c71448b91ac856a18d86dd1862754d979d5a78409a68a","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(fields):\n    return list(dict.fromkeys(fields))\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', 'b=2']), ['a=1', 'b=2'])\", \"check('fixture 2', solve(['a=1', 'a=1']), ['a=1', 'a=1'])\", \"check('fixture 3', solve([]), [])\", \"check('fixture 4', solve(['a=1']), ['a=1'])\"]\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":"ac9be494a5453f816ddcab0eb4c9b2c39a2d617bc34ffbafa5307adb00d9cf30","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(fields):\n    return [\", \".join(fields)] if fields else []\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', 'b=2']), ['a=1', 'b=2'])\", \"check('fixture 2', solve(['a=1', 'a=1']), ['a=1', 'a=1'])\", \"check('fixture 3', solve([]), [])\", \"check('fixture 4', solve(['a=1']), ['a=1'])\"]\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":"3dafcd92289588491cbcd274c68d5f7693e0ea52cb748f53357f685a3b414685","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(fields):\n    return list(fields)\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', 'b=2']), ['a=1', 'b=2'])\", \"check('fixture 2', solve(['a=1', 'a=1']), ['a=1', 'a=1'])\", \"check('fixture 3', solve([]), [])\", \"check('fixture 4', solve(['a=1']), ['a=1'])\"]\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-multiple-set-cookie-fields-are-not-comma-coalesced","generated_at":"2026-09-29T14:38:07.423182+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic proxy forwarding model isolates the multiple-set-cookie-fields-are-not-comma-coalesced policy at a network component boundary.","repair":"Apply the explicit multiple-set-cookie-fields-are-not-comma-coalesced contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `[\", \".join(fields)] if fields else []` for the multiple-set-cookie-fields-are-not-comma-coalesced decision.","sha256":"44eb19479cbc5eba6376b27591b591a1e5039cd760cac9b53b2eee0e6e35468b","title":"Multiple set cookie fields are not comma coalesced · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.216,"exit_code":1,"observations":[{"actual":["a=1"],"check":"fixture 2","expected":["a=1","a=1"],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":["a=1"],"check":"fixture 4","expected":["a=1"],"passed":true},{"actual":["a=1","b=2"],"check":"fixture 1","expected":["a=1","b=2"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"a=1\"], \"expected\": [\"a=1\", \"a=1\"], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a=1\"], \"expected\": [\"a=1\"], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"a=1\", \"b=2\"], \"expected\": [\"a=1\", \"b=2\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":35.047,"exit_code":1,"observations":[{"actual":["a=1, a=1"],"check":"fixture 2","expected":["a=1","a=1"],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":["a=1"],"check":"fixture 4","expected":["a=1"],"passed":true},{"actual":["a=1, b=2"],"check":"fixture 1","expected":["a=1","b=2"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"a=1, a=1\"], \"expected\": [\"a=1\", \"a=1\"], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a=1\"], \"expected\": [\"a=1\"], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"a=1, b=2\"], \"expected\": [\"a=1\", \"b=2\"], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":34.769,"exit_code":0,"observations":[{"actual":["a=1","a=1"],"check":"fixture 2","expected":["a=1","a=1"],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":["a=1"],"check":"fixture 4","expected":["a=1"],"passed":true},{"actual":["a=1","b=2"],"check":"fixture 1","expected":["a=1","b=2"],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"a=1\", \"a=1\"], \"expected\": [\"a=1\", \"a=1\"], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a=1\"], \"expected\": [\"a=1\"], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"a=1\", \"b=2\"], \"expected\": [\"a=1\", \"b=2\"], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}