{"abstract":"Datagram truncation is reported separately from copied length.","category":"Transport flow control","checks":4,"contract":"Bounded offline decision model: datagram truncation is reported separately from copied length. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"payload, capacity","evaluation_group":"xh-datagram-truncation-is-reported-separately-from-copied-length","failed_approach":"The attempted repair uses `(payload[:capacity],len(payload)>=capacity)` and still violates a separate fixture.","family":"xh-datagram-truncation-is-reported-separately-from-copied-length","id":"FA-7311","implementations":{"attempt":{"sha256":"994a64838edee833f4fc503c2653a4aa194b7a45139bb7ca132552bf1b2105ed","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(payload, capacity):\n    return (payload[:capacity],len(payload)>=capacity)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('abcdef', 3), ('abc', True))\", \"check('fixture 2', solve('abc', 3), ('abc', False))\", \"check('fixture 3', solve('', 0), ('', False))\", \"check('fixture 4', solve('a', 0), ('', True))\"]\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":"e720029fe4b8142760ed2707f3d39594fb7ef6bc81059b2d30dad71a8ad45bcd","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(payload, capacity):\n    return (payload[:capacity],False)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('abcdef', 3), ('abc', True))\", \"check('fixture 2', solve('abc', 3), ('abc', False))\", \"check('fixture 3', solve('', 0), ('', False))\", \"check('fixture 4', solve('a', 0), ('', True))\"]\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-datagram-truncation-is-reported-separately-from-copied-length","generated_at":"2026-09-29T14:38:10.594919+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic transport flow control model isolates the datagram-truncation-is-reported-separately-from-copied-length policy at a network component boundary.","root_cause":"The faulty implementation uses `(payload[:capacity],False)` for the datagram-truncation-is-reported-separately-from-copied-length decision.","sha256":"7f09f6ef70e5db34edfa35d87b446e2a816e2c35c804bd21dd80fc2a2cd0b599","title":"Datagram truncation is reported separately from copied length · 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":54.69,"exit_code":1,"observations":[{"actual":["abc",true],"check":"fixture 2","expected":["abc",false],"passed":false},{"actual":["",true],"check":"fixture 3","expected":["",false],"passed":false},{"actual":["",true],"check":"fixture 4","expected":["",true],"passed":true},{"actual":["abc",true],"check":"fixture 1","expected":["abc",true],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"abc\", true], \"expected\": [\"abc\", false], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [\"\", true], \"expected\": [\"\", false], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [\"\", true], \"expected\": [\"\", true], \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": [\"abc\", true], \"expected\": [\"abc\", true], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.981,"exit_code":1,"observations":[{"actual":["abc",false],"check":"fixture 2","expected":["abc",false],"passed":true},{"actual":["",false],"check":"fixture 3","expected":["",false],"passed":true},{"actual":["",false],"check":"fixture 4","expected":["",true],"passed":false},{"actual":["abc",false],"check":"fixture 1","expected":["abc",true],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": [\"abc\", false], \"expected\": [\"abc\", false], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"\", false], \"expected\": [\"\", false], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"\", false], \"expected\": [\"\", true], \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": [\"abc\", false], \"expected\": [\"abc\", true], \"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."}}