From 92f24b915785495a079cd249439962976665b51d Mon Sep 17 00:00:00 2001
From: Minh Vu <vuhoangminh97@gmail.com>
Date: Sun, 21 Jun 2026 20:44:46 +0200
Subject: [PATCH] fix: return error for nullable PyArrow structs

---
 arrow-pyarrow-testing/tests/pyarrow.rs | 33 ++++++++++++++++++++++++--
 arrow-pyarrow/src/lib.rs               | 10 ++++----
 2 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/arrow-pyarrow-testing/tests/pyarrow.rs b/arrow-pyarrow-testing/tests/pyarrow.rs
index 6f3606478c72..42324aefcf5a 100644
--- a/arrow-pyarrow-testing/tests/pyarrow.rs
+++ b/arrow-pyarrow-testing/tests/pyarrow.rs
@@ -42,9 +42,9 @@ use arrow_array::{
     Array, ArrayRef, BinaryViewArray, Int32Array, RecordBatch, StringArray, StringViewArray,
 };
 use arrow_pyarrow::{FromPyArrow, ToPyArrow};
-use pyo3::exceptions::PyTypeError;
-use pyo3::types::{PyAnyMethods, PyModule};
 use pyo3::Python;
+use pyo3::exceptions::{PyTypeError, PyValueError};
+use pyo3::types::{PyAnyMethods, PyModule};
 use std::ffi::CString;
 use std::sync::Arc;
 
@@ -125,6 +125,35 @@ value = NotATuple()
     });
 }
 
+#[test]
+fn test_from_pyarrow_nullable_struct_array() {
+    Python::initialize();
+
+    Python::attach(|py| {
+        let code = CString::new(
+            r#"
+import pyarrow as pa
+
+value = pa.array(
+    [{"a": 1}, None],
+    type=pa.struct([pa.field("a", pa.int32())]),
+)
+"#,
+        )
+        .unwrap();
+
+        let module = PyModule::from_code(py, code.as_c_str(), c"test.py", c"test_module").unwrap();
+        let value = module.getattr("value").unwrap();
+
+        let err = RecordBatch::from_pyarrow_bound(&value).unwrap_err();
+        assert!(err.is_instance_of::<PyValueError>(py));
+        assert_eq!(
+            err.to_string(),
+            "ValueError: Cannot convert nullable StructArray to RecordBatch, see StructArray documentation"
+        );
+    });
+}
+
 fn binary_view_column(num_variadic_buffers: usize) -> BinaryViewArray {
     let long_scalar = b"but soft what light through yonder window breaks".as_slice();
     let mut builder = BinaryViewBuilder::new().with_fixed_block_size(long_scalar.len() as u32);
diff --git a/arrow-pyarrow/src/lib.rs b/arrow-pyarrow/src/lib.rs
index c0d91d081113..c6038bc49866 100644
--- a/arrow-pyarrow/src/lib.rs
+++ b/arrow-pyarrow/src/lib.rs
@@ -369,11 +369,11 @@ impl FromPyArrow for RecordBatch {
             let schema =
                 unsafe { Arc::new(Schema::try_from(schema_ptr.as_ref()).map_err(to_py_err)?) };
             let (_fields, columns, nulls) = array.into_parts();
-            assert_eq!(
-                nulls.map(|n| n.null_count()).unwrap_or_default(),
-                0,
-                "Cannot convert nullable StructArray to RecordBatch, see StructArray documentation"
-            );
+            if nulls.map(|n| n.null_count()).unwrap_or_default() != 0 {
+                return Err(PyValueError::new_err(
+                    "Cannot convert nullable StructArray to RecordBatch, see StructArray documentation",
+                ));
+            }
             return RecordBatch::try_new_with_options(schema, columns, &options).map_err(to_py_err);
         }