test: regression test for LadybugDB/ladybug#1067 ORDER BY STRING then numeric

Merging sorted key blocks ignored trailing keys once all STRING keys
tied, misordering the second key (deterministic with multiple key
blocks, e.g. 20k rows).

Author: adsharma

test/test_issue.py

@@ -214,3 +214,27 @@ def test_issue_866_repeated_parameterized_write_then_vector_read(
 #     assert result.get_next() == [2]
 #     assert not result.has_next()
 #     result.close()
+
+
+def test_issue_1067_order_by_string_then_numeric(conn_db_readwrite: ConnDB) -> None:
+    # https://github.com/LadybugDB/ladybug/issues/1067
+    # KeyBlockMerger::compareTuplePtrWithStringCol ignored trailing keys once all
+    # STRING keys tied, misordering e.g. ORDER BY <STRING>, <numeric> when merging
+    # sorted key blocks (deterministic once the sort spills to multiple key blocks).
+    conn, _ = conn_db_readwrite
+    conn.execute(
+        "CREATE NODE TABLE Obs(id INT64, name STRING, value DOUBLE, PRIMARY KEY(id))"
+    )
+    conn.execute(
+        "COPY Obs FROM (UNWIND range(0, 19999) AS o RETURN o, "
+        "'item' + CAST(o % 3 AS STRING), CAST((o * 7919) % 100003 AS DOUBLE))"
+    )
+    result = conn.execute(
+        "MATCH (o:Obs) RETURN o.name, o.value ORDER BY o.name, o.value"
+    )
+    rows = result.get_all()
+    result.close()
+    # Fail loudly if ingestion ever changes: the bug only reproduces once the
+    # sort spills to multiple key blocks.
+    assert len(rows) == 20000
+    assert rows == sorted(rows)