[arrow-rs] branch master updated: fix: new_null_array for structs (#736)

[alamb]

This is an automated email from the ASF dual-hosted git repository.

alamb pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/master by this push:
     new 5af340c  fix: new_null_array for structs (#736)
5af340c is described below

commit 5af340c556c0d765113b5b4683f369790e612ede
Author: Ben Chambers <35960+bjchamb...@users.noreply.github.com>
AuthorDate: Thu Sep 9 13:02:10 2021 -0700

    fix: new_null_array for structs (#736)
---
 arrow/src/array/array.rs | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/arrow/src/array/array.rs b/arrow/src/array/array.rs
index 8cbac31..be19fea 100644
--- a/arrow/src/array/array.rs
+++ b/arrow/src/array/array.rs
@@ -448,18 +448,15 @@ pub fn new_null_array(data_type: &DataType, length: 
usize) -> ArrayRef {
                     .clone(),
             ],
         )),
-        DataType::Struct(fields) => make_array(ArrayData::new(
-            data_type.clone(),
-            length,
-            Some(length),
-            Some(MutableBuffer::new_null(length).into()),
-            0,
-            vec![],
-            fields
+        DataType::Struct(fields) => {
+            let fields: Vec<_> = fields
                 .iter()
-                .map(|field| ArrayData::new_empty(field.data_type()))
-                .collect(),
-        )),
+                .map(|field| (field.clone(), new_null_array(field.data_type(), 
length)))
+                .collect();
+
+            let null_buffer = MutableBuffer::new_null(length);
+            Arc::new(StructArray::from((fields, null_buffer.into())))
+        }
         DataType::Map(field, _keys_sorted) => {
             new_null_list_array::<i32>(data_type, field.data_type(), length)
         }
@@ -645,6 +642,23 @@ mod tests {
     }
 
     #[test]
+    fn test_null_struct() {
+        let struct_type =
+            DataType::Struct(vec![Field::new("data", DataType::Int64, false)]);
+        let array = new_null_array(&struct_type, 9);
+
+        let a = array.as_any().downcast_ref::<StructArray>().unwrap();
+        assert_eq!(a.len(), 9);
+        assert_eq!(a.column(0).len(), 9);
+        for i in 0..9 {
+            assert!(a.is_null(i));
+        }
+
+        // Make sure we can slice the resulting array.
+        a.slice(0, 5);
+    }
+
+    #[test]
     fn test_null_variable_sized() {
         let array = new_null_array(&DataType::Utf8, 9);
         let a = array.as_any().downcast_ref::<StringArray>().unwrap();