[Bug](function) fix wrong result about array_agg_foreach

be/src/vec/aggregate_functions/aggregate_function_array_agg.h

@@ -128,15 +128,7 @@ struct AggregateFunctionArrayAggData {
     }
 
     void merge(const Self& rhs) {
-        const auto size = rhs.null_map->size();
-        null_map->resize(size);
-        nested_column->reserve(size);
-        for (size_t i = 0; i < size; i++) {
-            const auto null_value = rhs.null_map->data()[i];
-            const auto data_value = rhs.nested_column->get_data()[i];
-            null_map->data()[i] = null_value;
-            nested_column->get_data().push_back(data_value);
-        }
+        column_data->insert_range_from(*rhs.column_data, 0, rhs.column_data->size());
     }
 };
 
@@ -229,15 +221,7 @@ struct AggregateFunctionArrayAggData<T> {
     }
 
     void merge(const Self& rhs) {
-        const auto size = rhs.null_map->size();
-        null_map->resize(size);
-        nested_column->reserve(size);
-        for (size_t i = 0; i < size; i++) {
-            const auto null_value = rhs.null_map->data()[i];
-            auto s = rhs.nested_column->get_data_at(i);
-            null_map->data()[i] = null_value;
-            nested_column->insert_data(s.data, s.size);
-        }
+        column_data->insert_range_from(*rhs.column_data, 0, rhs.column_data->size());
     }
 };
 

be/src/vec/aggregate_functions/aggregate_function_foreachv2.cpp

@@ -85,7 +85,7 @@ void register_aggregate_function_combinator_foreachv2(AggregateFunctionSimpleFac
         for (const auto& t : types) {
             auto item_type =
                     assert_cast<const DataTypeArray*>(remove_nullable(t).get())->get_nested_type();
-            transform_arguments.push_back((item_type));
+            transform_arguments.push_back(item_type);
         }
         auto nested_function_name = name.substr(0, name.size() - suffix.size());
         auto nested_function = factory.get(nested_function_name, transform_arguments, true,

regression-test/data/function_p0/test_agg_foreach_multi_instance.out

@@ -0,0 +1,7 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !sql --
+[null, 1, 2, 2, 3, 20, 100]
+
+-- !sql --
+[null, "114514", "123", "ab", "c", "cd", "efg"]
+

regression-test/suites/function_p0/test_agg_foreach_multi_instance.groovy

@@ -0,0 +1,47 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("test_agg_foreach_multi_instance") {
+   sql """
+       drop table if exists foreach_table_m;
+   """
+
+	sql """
+       CREATE TABLE IF NOT EXISTS foreach_table_m (
+              `id` INT(11) null COMMENT "",
+              `a` array<INT> null  COMMENT "",
+              `b` array<array<INT>>  null COMMENT "",
+              `s` array<String>  null  COMMENT ""
+            ) ENGINE=OLAP
+            DUPLICATE KEY(`id`)
+            DISTRIBUTED BY HASH(`id`) BUCKETS 10
+            PROPERTIES (
+            "replication_allocation" = "tag.location.default: 1",
+            "storage_format" = "V2"
+    );
+    """
+    sql """
+    insert into foreach_table_m values
+    (1,[1,2,3],[[1],[1,2,3],[2]],["ab","123","114514"]),
+    (2,[20],[[2]],["cd"]),
+    (3,[100],[[1]],["efg"]) , 
+    (4,null,[null],null),
+    (5,[null,2],[[2],null],[null,'c']);
+   """
+    qt_sql """select array_sort(array_flatten(array_agg_foreach(a))) from foreach_table_m;"""
+   	qt_sql """select array_sort(array_flatten(array_agg_foreach(s))) from foreach_table_m;"""
+}