From f71bed08caa6956fa3231900e70eaec6161ad33e Mon Sep 17 00:00:00 2001
From: Michael Widenius <monty@mariadb.org>
Date: Mon, 19 Jun 2017 06:37:43 +0300
Subject: [PATCH] Safety fix: lock binlog_end_pos before calling signal_update

The mutex is needed to ensure that sql thread should not not miss the error
signal.
---
 sql/rpl_parallel.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sql/rpl_parallel.cc b/sql/rpl_parallel.cc
index 5797b82d8fe..b274824a33b 100644
--- a/sql/rpl_parallel.cc
+++ b/sql/rpl_parallel.cc
@@ -256,7 +256,9 @@ signal_error_to_sql_driver_thread(THD *thd, rpl_group_info *rgi, int err)
   rgi->rli->stop_for_until= false;
   mysql_mutex_lock(rgi->rli->relay_log.get_log_lock());
   mysql_mutex_unlock(rgi->rli->relay_log.get_log_lock());
+  rgi->rli->relay_log.lock_binlog_end_pos();
   rgi->rli->relay_log.signal_update();
+  rgi->rli->relay_log.unlock_binlog_end_pos();
 }