{"abstract":"Partition injection reuses the first file fragment partition.","category":"Data systems","checks":7,"contract":"Read ordered file fragments [partition-values,physical-rows] under a projection of field names. Partition values override stale physical columns of the same name; unprojected fields disappear, missing fields become None, and physically empty fragments do not synthesize rows.","contract_signature":"d","evaluation_group":"s3-data-systems-partition-column-injection","failed_approach":"The final fragment partition also mislabels other fragments.","family":"s3-data-systems-partition-column-injection-fragment-binding","id":"FA-45246","implementations":{"attempt":{"sha256":"66ef830157714dadde5d2497086ff315a573a2c2c94fa11b4872eb19844bd575","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        fragments,projection=d\n        out=[]\n        for partition,rows in [(fragments[-1][0],r) for p,r in fragments]:\n            for row in rows:\n                merged=dict(row)\n                merged.update(partition)\n                out.append([merged.get(name) for name in projection])\n        return out\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 1}]]], ['v', 'p']]), [[1, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 1}]], [{'p': 'b'}, [{'v': 2}]]], ['p', 'v']]), [['a', 1], ['b', 2]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 1}]]], ['v', 'x']]), [[1, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 1}, {'v': 1}]]], ['v']]), [[1], [1]])\n    check('duplicate projection', solve([[[{}, [{'v': 1}]]], ['v', 'v']]), [[1, 1]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 2:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 2}]]], ['v', 'p']]), [[2, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 2}]], [{'p': 'b'}, [{'v': 3}]]], ['p', 'v']]), [['a', 2], ['b', 3]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 2}]]], ['v', 'x']]), [[2, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 2}, {'v': 2}]]], ['v']]), [[2], [2]])\n    check('duplicate projection', solve([[[{}, [{'v': 2}]]], ['v', 'v']]), [[2, 2]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 3:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 3}]]], ['v', 'p']]), [[3, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 3}]], [{'p': 'b'}, [{'v': 4}]]], ['p', 'v']]), [['a', 3], ['b', 4]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 3}]]], ['v', 'x']]), [[3, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 3}, {'v': 3}]]], ['v']]), [[3], [3]])\n    check('duplicate projection', solve([[[{}, [{'v': 3}]]], ['v', 'v']]), [[3, 3]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 4:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 4}]]], ['v', 'p']]), [[4, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 4}]], [{'p': 'b'}, [{'v': 5}]]], ['p', 'v']]), [['a', 4], ['b', 5]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 4}]]], ['v', 'x']]), [[4, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 4}, {'v': 4}]]], ['v']]), [[4], [4]])\n    check('duplicate projection', solve([[[{}, [{'v': 4}]]], ['v', 'v']]), [[4, 4]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 5:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 5}]]], ['v', 'p']]), [[5, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 5}]], [{'p': 'b'}, [{'v': 6}]]], ['p', 'v']]), [['a', 5], ['b', 6]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 5}]]], ['v', 'x']]), [[5, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 5}, {'v': 5}]]], ['v']]), [[5], [5]])\n    check('duplicate projection', solve([[[{}, [{'v': 5}]]], ['v', 'v']]), [[5, 5]])\n    check('no fragments', solve([[], ['v']]), [])\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":"9bb75292f1cd8b0647f3194179ec42103d17daee17b9b95b41a97bab2f03cfe0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        fragments,projection=d\n        out=[]\n        for partition,rows in [(fragments[0][0],r) for p,r in fragments]:\n            for row in rows:\n                merged=dict(row)\n                merged.update(partition)\n                out.append([merged.get(name) for name in projection])\n        return out\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 1}]]], ['v', 'p']]), [[1, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 1}]], [{'p': 'b'}, [{'v': 2}]]], ['p', 'v']]), [['a', 1], ['b', 2]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 1}]]], ['v', 'x']]), [[1, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 1}, {'v': 1}]]], ['v']]), [[1], [1]])\n    check('duplicate projection', solve([[[{}, [{'v': 1}]]], ['v', 'v']]), [[1, 1]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 2:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 2}]]], ['v', 'p']]), [[2, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 2}]], [{'p': 'b'}, [{'v': 3}]]], ['p', 'v']]), [['a', 2], ['b', 3]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 2}]]], ['v', 'x']]), [[2, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 2}, {'v': 2}]]], ['v']]), [[2], [2]])\n    check('duplicate projection', solve([[[{}, [{'v': 2}]]], ['v', 'v']]), [[2, 2]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 3:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 3}]]], ['v', 'p']]), [[3, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 3}]], [{'p': 'b'}, [{'v': 4}]]], ['p', 'v']]), [['a', 3], ['b', 4]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 3}]]], ['v', 'x']]), [[3, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 3}, {'v': 3}]]], ['v']]), [[3], [3]])\n    check('duplicate projection', solve([[[{}, [{'v': 3}]]], ['v', 'v']]), [[3, 3]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 4:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 4}]]], ['v', 'p']]), [[4, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 4}]], [{'p': 'b'}, [{'v': 5}]]], ['p', 'v']]), [['a', 4], ['b', 5]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 4}]]], ['v', 'x']]), [[4, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 4}, {'v': 4}]]], ['v']]), [[4], [4]])\n    check('duplicate projection', solve([[[{}, [{'v': 4}]]], ['v', 'v']]), [[4, 4]])\n    check('no fragments', solve([[], ['v']]), [])\nelif N == 5:\n    check('partition overrides', solve([[[{'p': 'new'}, [{'p': 'old', 'v': 5}]]], ['v', 'p']]), [[5, 'new']])\n    check('multiple fragments', solve([[[{'p': 'a'}, [{'v': 5}]], [{'p': 'b'}, [{'v': 6}]]], ['p', 'v']]), [['a', 5], ['b', 6]])\n    check('empty fragment', solve([[[{'p': 'a'}, []]], ['p']]), [])\n    check('missing projected', solve([[[{}, [{'v': 5}]]], ['v', 'x']]), [[5, None]])\n    check('duplicate rows', solve([[[{}, [{'v': 5}, {'v': 5}]]], ['v']]), [[5], [5]])\n    check('duplicate projection', solve([[[{}, [{'v': 5}]]], ['v', 'v']]), [[5, 5]])\n    check('no fragments', solve([[], ['v']]), [])\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":"Offline stipulated semantics over valid small inputs; no performance, concurrency, or production-engine conformance claim. 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":"s3-data-systems-partition-column-injection-fragment-binding","generated_at":"2026-09-29T14:44:20.455331+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded deterministic data engine model makes representation and changelog faults reproducible.","root_cause":"partition-column-injection: Partition injection reuses the first file fragment partition.","sha256":"2f578a180f330bacd9d5dc4f73daa210bd94410f639950b2efe6421adf911bef","title":"Partition injection reuses the first file fragment partition · 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":48.038,"exit_code":1,"observations":[{"actual":[[1,"new"]],"check":"partition overrides","expected":[[1,"new"]],"passed":true},{"actual":[["b",1],["b",2]],"check":"multiple fragments","expected":[["a",1],["b",2]],"passed":false},{"actual":[],"check":"empty fragment","expected":[],"passed":true},{"actual":[[1,null]],"check":"missing projected","expected":[[1,null]],"passed":true},{"actual":[[1],[1]],"check":"duplicate rows","expected":[[1],[1]],"passed":true},{"actual":[[1,1]],"check":"duplicate projection","expected":[[1,1]],"passed":true},{"actual":[],"check":"no fragments","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"partition overrides\", \"actual\": [[1, \"new\"]], \"expected\": [[1, \"new\"]], \"passed\": true}, {\"check\": \"multiple fragments\", \"actual\": [[\"b\", 1], [\"b\", 2]], \"expected\": [[\"a\", 1], [\"b\", 2]], \"passed\": false}, {\"check\": \"empty fragment\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"missing projected\", \"actual\": [[1, null]], \"expected\": [[1, null]], \"passed\": true}, {\"check\": \"duplicate rows\", \"actual\": [[1], [1]], \"expected\": [[1], [1]], \"passed\": true}, {\"check\": \"duplicate projection\", \"actual\": [[1, 1]], \"expected\": [[1, 1]], \"passed\": true}, {\"check\": \"no fragments\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.949,"exit_code":1,"observations":[{"actual":[[1,"new"]],"check":"partition overrides","expected":[[1,"new"]],"passed":true},{"actual":[["a",1],["a",2]],"check":"multiple fragments","expected":[["a",1],["b",2]],"passed":false},{"actual":[],"check":"empty fragment","expected":[],"passed":true},{"actual":[[1,null]],"check":"missing projected","expected":[[1,null]],"passed":true},{"actual":[[1],[1]],"check":"duplicate rows","expected":[[1],[1]],"passed":true},{"actual":[[1,1]],"check":"duplicate projection","expected":[[1,1]],"passed":true},{"actual":[],"check":"no fragments","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"partition overrides\", \"actual\": [[1, \"new\"]], \"expected\": [[1, \"new\"]], \"passed\": true}, {\"check\": \"multiple fragments\", \"actual\": [[\"a\", 1], [\"a\", 2]], \"expected\": [[\"a\", 1], [\"b\", 2]], \"passed\": false}, {\"check\": \"empty fragment\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"missing projected\", \"actual\": [[1, null]], \"expected\": [[1, null]], \"passed\": true}, {\"check\": \"duplicate rows\", \"actual\": [[1], [1]], \"expected\": [[1], [1]], \"passed\": true}, {\"check\": \"duplicate projection\", \"actual\": [[1, 1]], \"expected\": [[1, 1]], \"passed\": true}, {\"check\": \"no fragments\", \"actual\": [], \"expected\": [], \"passed\": true}], \"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."}}