Commit c96b6eb5ec changed the way mempool
code handles freed allocations that cannot be retained for later use as
"free list" items: it no longer uses different logic depending on
whether the internal allocator is used or the system one. However, that
commit did not update a relevant piece of code in isc_mempool_destroy(),
causing memory context statistics to always be off upon shutdown when
BIND 9 is built with -DISC_MEM_USE_INTERNAL_MALLOC=1. This causes
assertion failures. Update isc_mempool_destroy() accordingly in order
to prevent this issue from being triggered.
7df6070c02