From e84f3436c079a8264bf3052f64db31ba6fbddbff Mon Sep 17 00:00:00 2001
From: HuSen <husen.xjtu@gmail.com>
Date: Sat, 17 Aug 2024 18:48:55 +0800
Subject: [PATCH] Fix: handle NULL input for regex match operations (#12028)

---
 .../physical-expr/src/expressions/binary.rs   | 12 +++--
 datafusion/sqllogictest/test_files/regexp.slt | 45 +++++++++++++++++++
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/datafusion/physical-expr/src/expressions/binary.rs b/datafusion/physical-expr/src/expressions/binary.rs
index 06f54481a6fa..26885ae1350c 100644
--- a/datafusion/physical-expr/src/expressions/binary.rs
+++ b/datafusion/physical-expr/src/expressions/binary.rs
@@ -318,10 +318,14 @@ impl PhysicalExpr for BinaryExpr {
         // Attempt to use special kernels if one input is scalar and the other is an array
         let scalar_result = match (&lhs, &rhs) {
             (ColumnarValue::Array(array), ColumnarValue::Scalar(scalar)) => {
-                // if left is array and right is literal - use scalar operations
-                self.evaluate_array_scalar(array, scalar.clone())?.map(|r| {
-                    r.and_then(|a| to_result_type_array(&self.op, a, &result_type))
-                })
+                // if left is array and right is literal(not NULL) - use scalar operations
+                if scalar.is_null() {
+                    None
+                } else {
+                    self.evaluate_array_scalar(array, scalar.clone())?.map(|r| {
+                        r.and_then(|a| to_result_type_array(&self.op, a, &result_type))
+                    })
+                }
             }
             (_, _) => None, // default to array implementation
         };
diff --git a/datafusion/sqllogictest/test_files/regexp.slt b/datafusion/sqllogictest/test_files/regexp.slt
index c04021651a50..1685ed51afef 100644
--- a/datafusion/sqllogictest/test_files/regexp.slt
+++ b/datafusion/sqllogictest/test_files/regexp.slt
@@ -48,6 +48,51 @@ true
 true
 true
 
+query B
+SELECT str ~ NULL FROM t;
+----
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+
+query B
+select str ~ right('foo', NULL) FROM t;
+----
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+
+query B
+select right('foo', NULL) !~ str FROM t;
+----
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+
 query B
 SELECT regexp_like('foobarbequebaz', '');
 ----