From 03e36056eba1cbcccc87b28e28b91792dae5a417 Mon Sep 17 00:00:00 2001
From: Mingyu Chen <morningman.cmy@gmail.com>
Date: Tue, 5 Jan 2021 09:48:38 +0800
Subject: [PATCH] [Bug] Fix bug that the min/max function has an error in
 handling string null values. (#5189)

null should be ignored in min/max function.
And if there is no data, null should be return.

Co-authored-by: morningman <chenmingyu@baidu.com>
---
 be/src/olap/aggregate_func.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/be/src/olap/aggregate_func.h b/be/src/olap/aggregate_func.h
index 1c902af0a0..c3ddf3ade2 100644
--- a/be/src/olap/aggregate_func.h
+++ b/be/src/olap/aggregate_func.h
@@ -300,6 +300,7 @@ struct AggregateFuncTraits<OLAP_FIELD_AGGREGATION_MAX, OLAP_FIELD_TYPE_VARCHAR>
                 memory_copy(dst_slice->data, src_slice->data, src_slice->size);
                 dst_slice->size = src_slice->size;
             }
+            dst->set_is_null(false);
         }
     }
 };