"Move innobase_release_stat_resources(trx) outside the 'if' in
ha_innobase::external_lock(). That would add more safety that whatever
MySQL does at a query end, there would be no risk of a hang on the btr
search latch."

Also call innobase_release_temporary_latches() in the beginning of
ha_innobase::close().

Approved by:	Heikki