From 55bf1e3579550ca5cb8b4cd51cdc59f9bf5920f1 Mon Sep 17 00:00:00 2001
From: Ran Reichman <ran@flarion.io>
Date: Wed, 7 Oct 2026 15:23:34 -0400
Subject: [PATCH] Return NULL from Spark char for a NULL scalar input

---
 datafusion/spark/src/function/string/char.rs             | 3 +++
 datafusion/sqllogictest/test_files/spark/string/char.slt | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/datafusion/spark/src/function/string/char.rs b/datafusion/spark/src/function/string/char.rs
index 5d6de3ae368e3..6e8666f0b89f4 100644
--- a/datafusion/spark/src/function/string/char.rs
+++ b/datafusion/spark/src/function/string/char.rs
@@ -100,6 +100,9 @@ fn spark_chr(args: &[ColumnarValue]) -> Result<ColumnarValue> {
                 }
             }
         }
+        ColumnarValue::Scalar(ScalarValue::Int64(None)) => {
+            Ok(ColumnarValue::Scalar(ScalarValue::Utf8(None)))
+        }
         _ => exec_err!("The argument must be an Int64 array or scalar."),
     }
 }
diff --git a/datafusion/sqllogictest/test_files/spark/string/char.slt b/datafusion/sqllogictest/test_files/spark/string/char.slt
index 152ebfe8053e8..47aa1dc844e05 100644
--- a/datafusion/sqllogictest/test_files/spark/string/char.slt
+++ b/datafusion/sqllogictest/test_files/spark/string/char.slt
@@ -25,6 +25,11 @@ SELECT char(321::INT);
 ----
 A
 
+query T
+SELECT char(NULL::INT);
+----
+NULL
+
 query T
 SELECT char(a) FROM (VALUES (-1::INT), (0::INT), (65::INT), (321::INT)) AS t(a);
 ----