From b503bad51d4f1068b17be967c4e5f9b6393d490e Mon Sep 17 00:00:00 2001
From: flynn <fenglv15@mails.ucas.ac.cn>
Date: Sun, 28 Jul 2024 14:42:14 +0000
Subject: [PATCH] Fix crash of uniq and uniqTheta with empty tuple argument

---
 src/AggregateFunctions/UniqVariadicHash.h                 | 3 +++
 tests/queries/0_stateless/03208_uniq_with_empty_tuple.sql | 3 +++
 2 files changed, 6 insertions(+)
 create mode 100644 tests/queries/0_stateless/03208_uniq_with_empty_tuple.sql

diff --git a/src/AggregateFunctions/UniqVariadicHash.h b/src/AggregateFunctions/UniqVariadicHash.h
index 5bb245397d4..279feed8bc6 100644
--- a/src/AggregateFunctions/UniqVariadicHash.h
+++ b/src/AggregateFunctions/UniqVariadicHash.h
@@ -67,6 +67,9 @@ struct UniqVariadicHash<false, true>
 {
     static UInt64 apply(size_t num_args, const IColumn ** columns, size_t row_num)
     {
+        if (!num_args)
+            return 0;
+
         UInt64 hash;
 
         const auto & tuple_columns = assert_cast<const ColumnTuple *>(columns[0])->getColumns();
diff --git a/tests/queries/0_stateless/03208_uniq_with_empty_tuple.sql b/tests/queries/0_stateless/03208_uniq_with_empty_tuple.sql
new file mode 100644
index 00000000000..4c5705261f0
--- /dev/null
+++ b/tests/queries/0_stateless/03208_uniq_with_empty_tuple.sql
@@ -0,0 +1,3 @@
+-- https://github.com/ClickHouse/ClickHouse/issues/67303
+SELECT uniqTheta(tuple());
+SELECT uniq(tuple());