Analysis: There is race between drop table and encryption threads that
could cause encryption thread to enter mutex that has been already
released.
Fix: When destroying crypt_data first enter the mutex and set crypt data
unavailable, then release the memory and clean up the data. This should
make the race more unprobable. Additionally, added big_test for
create_or_replace as it could fail testcase timeout
if you have slow I/O (tested that testcase passes with --mem).
Test create_or_replace should make sure that background decrypt
operation is finished and flush all dirty pages using restart
to clean up the database before ending.
* support statically compiled file_key_management when possible
* rename encryption.encryption_create_or_replace -> encryption.create_or_replace
* delete unnecessary *.opt file (including
have_key_management_plugin.inc is enough)
* remove unnecessary LOWER() for strings that are compared
case insensitively anyway