From c4b2ddd688ddb66b001ae80be4faaf599d3753a3 Mon Sep 17 00:00:00 2001
From: lihangyu <15605149486@163.com>
Date: Fri, 24 May 2024 19:10:07 +0800
Subject: [PATCH] [Fix](Variant) clear block after a flush complete (#35226)
 (#35372)

Otherwise result in crash

```
*** SIGSEGV address not mapped to object (@0x0) received by PID 4149909 (TID 4152328 OR 0x7efefc60d700) from PID 0; stack trace: ***
 0# doris::signal::(anonymous namespace)::FailureSignalHandler(int, siginfo_t*, void*) at /home/zcp/repo_center/doris_master/doris/be/src/common/signal_handler.h:421
 1# PosixSignals::chained_handler(int, siginfo*, void*) [clone .part.0] in /usr/lib/jvm/java-17-openjdk-amd64/lib/server/libjvm.so
 2# JVM_handle_linux_signal in /usr/lib/jvm/java-17-openjdk-amd64/lib/server/libjvm.so
 3# 0x00007F031AD0E090 in /lib/x86_64-linux-gnu/libc.so.6
 4# doris::Status doris::vectorized::MutableBlock::merge_impl<doris::vectorized::Block const&>(doris::vectorized::Block const&) at /home/zcp/repo_center/doris_master/doris/be/src/vec/core/block.h:586
 5# doris::Status doris::vectorized::MutableBlock::merge<doris::vectorized::Block const&>(doris::vectorized::Block const&) at /home/zcp/repo_center/doris_master/doris/be/src/vec/core/block.h:521
```
---
 be/src/olap/rowset/segment_creator.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/be/src/olap/rowset/segment_creator.cpp b/be/src/olap/rowset/segment_creator.cpp
index ffa8a1b291..f7b364a9fd 100644
--- a/be/src/olap/rowset/segment_creator.cpp
+++ b/be/src/olap/rowset/segment_creator.cpp
@@ -389,6 +389,7 @@ Status SegmentCreator::add_block(const vectorized::Block* block) {
         if (_buffer_block.allocated_bytes() > config::write_buffer_size) {
             vectorized::Block block = _buffer_block.to_block();
             RETURN_IF_ERROR(flush_single_block(&block));
+            _buffer_block.clear();
         } else {
             RETURN_IF_ERROR(_buffer_block.merge(*block));
         }
@@ -420,6 +421,7 @@ Status SegmentCreator::flush() {
     if (_buffer_block.rows() > 0) {
         vectorized::Block block = _buffer_block.to_block();
         RETURN_IF_ERROR(flush_single_block(&block));
+        _buffer_block.clear();
     }
     if (_flush_writer == nullptr) {
         return Status::OK();