Invalid write/read reported by Valgrind in 'update_group_replication_set_writer'.

[JavierJF]

• A clear description of the issue

Valgrind reports invalid writes/reads at:

MySQL_HostGroups_Manager::update_group_replication_set_writer(char*, int, int) (MySQL_HostGroups_Manager.cpp:4092)

• ProxySQL version

• v2.0.16.

• v2.1.0 should also be affected.

• OS version

NAME="Arch Linux"
PRETTY_NAME="Arch Linux"
ID=arch
BUILD_ID=rolling

• The steps to reproduce the issue

Start ProxySQL configured with a MySQL cluster using group replication.

• The full ProxySQL error log (default location: /var/lib/proxysql/proxysql.log)

Both ProxySQL log and valgrind log can be found attached:

• proxysql.log
• valgrind.txt