From 7c2ebe064d224aa2e1923f905bed271373152bda Mon Sep 17 00:00:00 2001
From: Junming Chen <junming.chen.r@outlook.com>
Date: Sun, 15 Oct 2023 16:34:38 +0800
Subject: [PATCH] fix bug

---
 cpp/src/arrow/compute/kernels/aggregate_basic_internal.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpp/src/arrow/compute/kernels/aggregate_basic_internal.h b/cpp/src/arrow/compute/kernels/aggregate_basic_internal.h
index 6ccdac952298b..fddc142669bf9 100644
--- a/cpp/src/arrow/compute/kernels/aggregate_basic_internal.h
+++ b/cpp/src/arrow/compute/kernels/aggregate_basic_internal.h
@@ -939,7 +939,7 @@ struct DictionaryMinMaxImpl : public ScalarAggregator {
     if (dict->length() == 0) {
       return Status::OK();
     }
-    this->has_nulls = compacted_dict_arr.null_count() > 0;
+    this->has_nulls |= compacted_dict_arr.null_count() > 0;
     this->count += compacted_dict_arr.length() - compacted_dict_arr.null_count();
 
     Datum dict_values(dict);