{"abstract":"Udp zero length datagram is data not stream eof.","category":"Transport flow control","checks":4,"contract":"Bounded offline decision model: udp zero length datagram is data not stream eof. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"length, datagram","evaluation_group":"xh-udp-zero-length-datagram-is-data-not-stream-eof","failed_approach":"The attempted repair uses `'data'` and still violates a separate fixture.","family":"xh-udp-zero-length-datagram-is-data-not-stream-eof","id":"FA-7306","implementations":{"attempt":{"sha256":"6981154bc4d9defd6ce51bd5a063e5e3150a14a6779f4d32583b808d9f4afaf0","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(length, datagram):\n    return 'data'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(0, True), 'data')\", \"check('fixture 2', solve(0, False), 'eof')\", \"check('fixture 3', solve(3, True), 'data')\", \"check('fixture 4', solve(3, False), 'data')\"]\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":"87bab9d3a84bce6fe75305c2c684ace0fd3e93cbb9e2dd67edb1fc75f658c9d4","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(length, datagram):\n    return 'data' if length else 'eof'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(0, True), 'data')\", \"check('fixture 2', solve(0, False), 'eof')\", \"check('fixture 3', solve(3, True), 'data')\", \"check('fixture 4', solve(3, False), 'data')\"]\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-udp-zero-length-datagram-is-data-not-stream-eof","generated_at":"2026-09-29T14:38:10.581395+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic transport flow control model isolates the udp-zero-length-datagram-is-data-not-stream-eof policy at a network component boundary.","root_cause":"The faulty implementation uses `'data' if length else 'eof'` for the udp-zero-length-datagram-is-data-not-stream-eof decision.","sha256":"d09d8c24a82af40238b13a3845186283e817fe22d99b7043259cda71f7799eab","title":"Udp zero length datagram is data not stream eof · 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":54.135,"exit_code":1,"observations":[{"actual":"data","check":"fixture 2","expected":"eof","passed":false},{"actual":"data","check":"fixture 3","expected":"data","passed":true},{"actual":"data","check":"fixture 4","expected":"data","passed":true},{"actual":"data","check":"fixture 1","expected":"data","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"data\", \"expected\": \"eof\", \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": \"data\", \"expected\": \"data\", \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": \"data\", \"expected\": \"data\", \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": \"data\", \"expected\": \"data\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":43.828,"exit_code":1,"observations":[{"actual":"eof","check":"fixture 2","expected":"eof","passed":true},{"actual":"data","check":"fixture 3","expected":"data","passed":true},{"actual":"data","check":"fixture 4","expected":"data","passed":true},{"actual":"eof","check":"fixture 1","expected":"data","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": \"eof\", \"expected\": \"eof\", \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": \"data\", \"expected\": \"data\", \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": \"data\", \"expected\": \"data\", \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": \"eof\", \"expected\": \"data\", \"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."}}