add test for arrow conversion

py-polars/tests/unit/interop/test_interop.py

@@ -766,3 +766,11 @@ def test_df_pycapsule_interface() -> None:
     df2 = pl.from_arrow(out)
     assert isinstance(df2, pl.DataFrame)
     assert df.equals(df2)
+
+
+def test_misaligned_nested_arrow_19097() -> None:
+    a = pl.Series("a", [1, 2, 3])
+    a = a.slice(1, 2)  # by slicing we offset=1 the values
+    a = a.replace(2, None)  # then we add a validity mask with offset=0
+    a = a.reshape((2, 1))  # then we make it nested
+    assert_series_equal(pl.Series(a.to_arrow()), a)