[Fix](memtable) fix shrink_memtable_by_agg should also update `_row…

…_in_blocks` (apache#28536)

Otherwise using the stale `_row_in_blocks` will result in heap-buffer-overflow

```
==2695213==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62900122e210 at pc 0x56524744aecf bp 0x7f62c595ef7
0 sp 0x7f62c595ef68
READ of size 8 at 0x62900122e210 thread T1627 (MemTableFlushTh)
    #0 0x56524744aece in doris::vectorized::ColumnVector<long>::insert_indices_from(doris::vectorized::IColumn const&, unsigned int const*, unsigned int const*) /mnt/disk2/lihangyu/doris/be/src/vec/columns/column_vector.cpp:378:33
    apache#1 0x5652472a7538 in doris::vectorized::ColumnNullable::insert_indices_from(doris::vectorized::IColumn const&, unsigned int const*, unsigned int const*) /mnt/disk2/lihangyu/doris/be/src/vec/columns/column_nullable.cpp:310:25
    apache#2 0x56524782a62a in doris::vectorized::MutableBlock::add_rows(doris::vectorized::Block const*, unsigned int const*, unsigned int const*) /mnt/disk2/lihangyu/doris/be/src/vec/core/block.cpp:961:14
    apache#3 0x565233f187ae in doris::MemTable::_put_into_output(doris::vectorized::Block&) /mnt/disk2/lihangyu/doris/be/src/olap/memtable.cpp:248:27
    apache#4 0x565233f1db66 in doris::MemTable::to_block() /mnt/disk2/lihangyu/doris/be/src/olap/memtable.cpp:496:13
    apache#5 0x565233efae60 in doris::FlushToken::_do_flush_memtable(doris::MemTable*, int, long*) /mnt/disk2/lihangyu/doris/be/src/olap/memtable_flush_executor.cpp:121:62
    apache#6 0x565233efc8d6 in doris::FlushToken::_flush_memtable(doris::MemTable*, int, long) /mnt/disk2/lihangyu/doris/be/src/olap/memtable_flush_executor.cpp:150:16
    apache#7 0x565233f0c5eb in doris::MemtableFlushTask::run() /mnt/disk2/lihangyu/doris/be/src/olap/memtable_flush_executor.cpp:58:23
```

be/src/olap/memtable.cpp

@@ -426,6 +426,8 @@ void MemTable::_aggregate() {
         _output_mutable_block =
                 vectorized::MutableBlock::build_mutable_block(empty_input_block.get());
         _output_mutable_block.clear_column_data();
+        _row_in_blocks = temp_row_in_blocks;
+        _last_sorted_pos = _row_in_blocks.size();
     }
 }
 

regression-test/suites/load_p0/insert/test_insert_with_aggregation_memtable.groovy

@@ -0,0 +1,139 @@
+// 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_insert_with_aggregation_memtable", "nonConcurrent") {
+    def backendId_to_backendIP = [:]
+    def backendId_to_backendHttpPort = [:]
+    def backendId_to_params = [string:[:]]
+    getBackendIpHttpPort(backendId_to_backendIP, backendId_to_backendHttpPort);
+
+    def set_be_param = { paramName, paramValue ->
+        // for eache be node, set paramName=paramValue
+        for (String id in backendId_to_backendIP.keySet()) {
+		    def beIp = backendId_to_backendIP.get(id)
+		    def bePort = backendId_to_backendHttpPort.get(id)
+		    def (code, out, err) = curl("POST", String.format("http://%s:%s/api/update_config?%s=%s", beIp, bePort, paramName, paramValue))
+		    assertTrue(out.contains("OK"))
+	    }
+    }
+
+    def reset_be_param = { paramName ->
+        // for eache be node, reset paramName to default
+        for (String id in backendId_to_backendIP.keySet()) {
+            def beIp = backendId_to_backendIP.get(id)
+            def bePort = backendId_to_backendHttpPort.get(id)
+            def original_value = backendId_to_params.get(id).get(paramName)
+            def (code, out, err) = curl("POST", String.format("http://%s:%s/api/update_config?%s=%s", beIp, bePort, paramName, original_value))
+            assertTrue(out.contains("OK"))
+        }
+    }
+
+    def get_be_param = { paramName ->
+        // for eache be node, get param value by default
+        def paramValue = ""
+        for (String id in backendId_to_backendIP.keySet()) {
+            def beIp = backendId_to_backendIP.get(id)
+            def bePort = backendId_to_backendHttpPort.get(id)
+            // get the config value from be
+            def (code, out, err) = curl("GET", String.format("http://%s:%s/api/show_config?conf_item=%s", beIp, bePort, paramName))
+            assertTrue(code == 0)
+            assertTrue(out.contains(paramName))
+            // parsing
+            def resultList = parseJson(out)[0]
+            assertTrue(resultList.size() == 4)
+            // get original value
+            paramValue = resultList[2]
+            backendId_to_params.get(id, [:]).put(paramName, paramValue)
+        }
+    }
+
+    def testTable = "test_memtable_enable_with_aggregate"
+    sql """ DROP TABLE IF EXISTS ${testTable}"""
+    def testTableDDL = """
+        create table ${testTable} 
+        (
+            `id` LARGEINT NOT NULL,
+            `k1` DATE NOT NULL,
+            `k2` VARCHAR(20),
+            `k3` SMALLINT,
+            `k4` TINYINT,
+            `k5` DATETIME REPLACE DEFAULT "1970-01-01 00:00:00",
+            `k6` BIGINT SUM DEFAULT "0",
+            `k7` INT MAX DEFAULT "0",
+            `k8` INT MIN DEFAULT "99999"
+        )
+        AGGREGATE KEY(`id`, `k1`, `k2`, `k3`, `k4`)
+        DISTRIBUTED BY HASH(`id`) BUCKETS 1
+        PROPERTIES (
+            "replication_allocation" = "tag.location.default: 1"
+        );
+    """
+    def insert_sql = """
+        insert into ${testTable} values
+        (10000,"2017-10-01","北京",20,0,"2017-10-01 06:00:00",20,10,10),
+        (10000,"2017-10-01","北京",20,0,"2017-10-01 07:00:00",15,2,2),
+        (10001,"2017-10-01","北京",30,1,"2017-10-01 17:05:45",2,22,22),
+        (10002,"2017-10-02","上海",20,1,"2017-10-02 12:59:12",200,5,5),
+        (10003,"2017-10-02","广州",32,0,"2017-10-02 11:20:00",30,11,11),
+        (10004,"2017-10-01","深圳",35,0,"2017-10-01 10:00:15",100,3,3),
+        (10004,"2017-10-03","深圳",35,0,"2017-10-03 10:20:22",11,6,6);
+    """
+
+    sql testTableDDL
+    sql "sync"
+    sql insert_sql
+    sql "sync"
+    qt_sql "select * from ${testTable} order by id asc"
+
+    // store the original value
+    get_be_param("enable_shrink_memory")
+    get_be_param("write_buffer_size_for_agg")
+
+    // the original value is false
+    set_be_param("enable_shrink_memory", "true")
+    // the original value is 400MB
+    set_be_param("write_buffer_size_for_agg", "512") // change it to 0.5KB
+    sql """ DROP TABLE IF EXISTS ${testTable}"""
+    sql testTableDDL
+    sql "sync"
+    sql insert_sql
+    sql "sync"
+    qt_sql "select * from ${testTable} order by id asc"
+
+    // test with mv
+    def table_name = "agg_shrink"
+    sql "DROP TABLE IF EXISTS ${table_name}"
+    sql """
+        CREATE TABLE IF NOT EXISTS ${table_name} (
+            k bigint,
+            v text 
+        )
+        DUPLICATE KEY(`k`)
+        DISTRIBUTED BY HASH(k) BUCKETS 4
+        properties("replication_num" = "1");
+    """
+    set_be_param("write_buffer_size_for_agg", "10240") // change it to 10KB
+    sql """INSERT INTO ${table_name} SELECT *, '{"k1":1, "k2": "hello world", "k3" : [1234], "k4" : 1.10000, "k5" : [[123]]}' FROM numbers("number" = "4096")"""
+    sql """INSERT INTO ${table_name} SELECT k, v from ${table_name}"""
+    sql """INSERT INTO ${table_name} SELECT k, v from ${table_name}"""
+    createMV("""create materialized view var_cnt as select k, count(k) from ${table_name} group by k""")    
+    sql """INSERT INTO ${table_name} SELECT k, v from ${table_name} limit 8101"""
+
+    reset_be_param("enable_shrink_memory")
+    reset_be_param("write_buffer_size_for_agg")
+
+}