From 024d898b0e2596736def31d22598f49c60ce4e64 Mon Sep 17 00:00:00 2001
From: robot-clickhouse <robot-clickhouse@users.noreply.github.com>
Date: Sat, 5 Oct 2024 09:09:14 +0000
Subject: [PATCH] Backport #69787 to 24.8: Fix 'Bad get' in maxMap state
 serialization

---
 src/AggregateFunctions/AggregateFunctionSumMap.cpp           | 5 +++--
 .../03237_max_map_state_decimal_serialization.reference      | 1 +
 .../03237_max_map_state_decimal_serialization.sql            | 1 +
 3 files changed, 5 insertions(+), 2 deletions(-)
 create mode 100644 tests/queries/0_stateless/03237_max_map_state_decimal_serialization.reference
 create mode 100644 tests/queries/0_stateless/03237_max_map_state_decimal_serialization.sql

diff --git a/src/AggregateFunctions/AggregateFunctionSumMap.cpp b/src/AggregateFunctions/AggregateFunctionSumMap.cpp
index 9a94c3dfe1a..099f110b775 100644
--- a/src/AggregateFunctions/AggregateFunctionSumMap.cpp
+++ b/src/AggregateFunctions/AggregateFunctionSumMap.cpp
@@ -298,12 +298,13 @@ public:
                     Field value = values[col_idx];
 
                     /// Compatibility with previous versions.
-                    if (value.getType() == Field::Types::Decimal32)
+                    WhichDataType value_type(values_types[col_idx]);
+                    if (value_type.isDecimal32())
                     {
                         auto source = value.safeGet<DecimalField<Decimal32>>();
                         value = DecimalField<Decimal128>(source.getValue(), source.getScale());
                     }
-                    else if (value.getType() == Field::Types::Decimal64)
+                    else if (value_type.isDecimal64())
                     {
                         auto source = value.safeGet<DecimalField<Decimal64>>();
                         value = DecimalField<Decimal128>(source.getValue(), source.getScale());
diff --git a/tests/queries/0_stateless/03237_max_map_state_decimal_serialization.reference b/tests/queries/0_stateless/03237_max_map_state_decimal_serialization.reference
new file mode 100644
index 00000000000..31b1da2af43
--- /dev/null
+++ b/tests/queries/0_stateless/03237_max_map_state_decimal_serialization.reference
@@ -0,0 +1 @@
+{"x":"\u0001\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000"}
diff --git a/tests/queries/0_stateless/03237_max_map_state_decimal_serialization.sql b/tests/queries/0_stateless/03237_max_map_state_decimal_serialization.sql
new file mode 100644
index 00000000000..8742f470cf0
--- /dev/null
+++ b/tests/queries/0_stateless/03237_max_map_state_decimal_serialization.sql
@@ -0,0 +1 @@
+select maxMapState([0], [toDateTime64(0, 0)]) as x format JSONEachRow;