The issue of the current bug is unguarded access to mi->slave_running
by the shutdown thread calling end_slave() that is bug#29968
(alas happened not to be cross-linked with the current bug)
Fixed:
with removing the unguarded read of the running status
and perform reading it in terminate_slave_thread()
at time run_lock is taken (mostly bug#29968 backporting, still with some
improvements over that patch - see the error reporting from
terminate_slave_thread()).
Issue of bug#38716 is fixed here for 5.0 branch as well.
Note:
There has been a separate artifact identified -
a race condition between init_slave() and end_slave() -
reported as Bug#44467.
