I added this info to WL#4610.
Ingo Strüwing wrote:
> Hi Jørgen,
> Rafal and I tracked the problem down to a bug in be_default.cc.
> In Backup::get_data() we have a wrong "optimization":
> Optimization: If this is the last table to read, close the tables and
> kill the lock thread. This only applies iff we are using the thread.
> if (locking_thd->tables_in_backup->next_global == NULL)
> Remove these lines and the INSERT blocks in wait_for_lock() as it should.
> The problem was that the locking thread was killed too early.
> Rafal and I agree that you can add this change to your patch. We don't
> need a dedicated bug report for it.