<rant>
I'm sure I would be able to get a definitive confirmation if
MySQL/MariaDB could be tested with ThreadSanitizer. But at the moment
it's a complete hell full of benign races (most of which seem to be in
InnoDB), so it's impossible to filter out real races from developers'
ignorance... :(
I hope sometimes someone will see importance of this problem and will
have time to chase and fix everything...
</rant>