fix: return correct length array for scalar null input to calculate_binary_math

datafusion/functions/src/utils.rs

@@ -147,7 +147,7 @@ where
             if scalar.is_null() {
                 // Null scalar is castable to any numeric, creating a non-null expression.
                 // Provide null array explicitly to make result null
-                PrimitiveArray::<O>::new_null(1)
+                PrimitiveArray::<O>::new_null(left.len())
             } else {
                 let right = R::Native::try_from(scalar.clone()).map_err(|_| {
                     DataFusionError::NotImplemented(format!(
@@ -363,12 +363,30 @@ pub mod test {
         };
     }
 
-    use arrow::datatypes::DataType;
+    use arrow::{
+        array::Int32Array,
+        datatypes::{DataType, Int32Type},
+    };
     use itertools::Either;
     pub(crate) use test_function;
 
     use super::*;
 
+    #[test]
+    fn test_calculate_binary_math_scalar_null() {
+        let left = Int32Array::from(vec![1, 2]);
+        let right = ColumnarValue::Scalar(ScalarValue::Int32(None));
+        let result = calculate_binary_math::<Int32Type, Int32Type, Int32Type, _>(
+            &left,
+            &right,
+            |x, y| Ok(x + y),
+        )
+        .unwrap();
+
+        assert_eq!(result.len(), 2);
+        assert_eq!(result.null_count(), 2);
+    }
+
     #[test]
     fn string_to_int_type() {
         let v = utf8_to_int_type(&DataType::Utf8, "test").unwrap();