{"abstract":"Websocket mask index continues across buffer chunks.","category":"WebSocket and browser transport policies","checks":4,"contract":"Bounded offline decision model: websocket mask index continues across buffer chunks. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"offset, mask_length","evaluation_group":"xh-websocket-mask-index-continues-across-buffer-chunks","failed_approach":"The attempted repair uses `offset // mask_length` and still violates a separate fixture.","family":"xh-websocket-mask-index-continues-across-buffer-chunks","id":"FA-7611","implementations":{"attempt":{"sha256":"06e8a0a2c8e6e0bf83e7cd2bb3e23f6670c4127b0ba6348764f95a013c9f9365","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(offset, mask_length):\n    return offset // mask_length\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(5, 4), 1)\", \"check('fixture 2', solve(7, 4), 3)\", \"check('fixture 3', solve(0, 4), 0)\", \"check('fixture 4', solve(4, 4), 0)\"]\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":"efd73de7c104bc49a51cae0380ba16582bbcd9b431aa5371e541841bd6b9226e","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(offset, mask_length):\n    return 0\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(5, 4), 1)\", \"check('fixture 2', solve(7, 4), 3)\", \"check('fixture 3', solve(0, 4), 0)\", \"check('fixture 4', solve(4, 4), 0)\"]\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-websocket-mask-index-continues-across-buffer-chunks","generated_at":"2026-09-29T14:38:13.604467+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic websocket and browser transport policies model isolates the websocket-mask-index-continues-across-buffer-chunks policy at a network component boundary.","root_cause":"The faulty implementation uses `0` for the websocket-mask-index-continues-across-buffer-chunks decision.","sha256":"22c9c73f6f7ca6c6484ae171982247c663846fa6de5ccbd59d9f2ebb7527b655","title":"Websocket mask index continues across buffer chunks · 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":41.141,"exit_code":1,"observations":[{"actual":1,"check":"fixture 2","expected":3,"passed":false},{"actual":0,"check":"fixture 3","expected":0,"passed":true},{"actual":1,"check":"fixture 4","expected":0,"passed":false},{"actual":1,"check":"fixture 1","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 1, \"expected\": 3, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.655,"exit_code":1,"observations":[{"actual":0,"check":"fixture 2","expected":3,"passed":false},{"actual":0,"check":"fixture 3","expected":0,"passed":true},{"actual":0,"check":"fixture 4","expected":0,"passed":true},{"actual":0,"check":"fixture 1","expected":1,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 0, \"expected\": 3, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 0, \"expected\": 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."}}