Issue FLUSH TABLES to prevent unintended corruption of
crash-unsafe tables when the server is killed.

The issue was that my_errno was not set properly when a repair was killed,
which confused the rpl_killed_ddl script.

I also added an extra test line in varchar.inc to ensure we don't give
duplicate error rows.

In 10.2, the definition of simple_counter resides in the file
sync0types.h, not in the file os0sync.h which has been removed.

There is a race condition related to the variable
srv_stats.n_lock_wait_current_count, which is only
incremented and decremented by the function lock_wait_suspend_thread(),

The incrementing is protected by lock_sys->wait_mutex, but the
decrementing does not appear to be protected by anything.
This mismatch could allow the counter to be corrupted when a
transactional InnoDB table or record lock wait is terminating
roughly at the same time with the start of a wait on a
(possibly different) lock.

ib_counter_t: Remove some unused methods. Prevent instantiation for N=1.
Add an inc() method that takes a slot index as a parameter.

single_indexer_t: Remove.

simple_counter<typename Type, bool atomic=false>: A new counter wrapper.
Optionally use atomic memory operations for modifying the counter.
Aligned to the cache line size.

lsn_ctr_1_t, ulint_ctr_1_t, int64_ctr_1_t: Define as simple_counter<Type>.
These counters are either only incremented (and we do not care about
losing some increment operations), or the increment/decrement operations
are protected by some mutex.

srv_stats_t::os_log_pending_writes: Document that the number is protected
by log_sys->mutex.

srv_stats_t::n_lock_wait_current_count: Use simple_counter<ulint, true>,
that is, atomic inc() and dec() operations.

lock_wait_suspend_thread(): Release the mutexes before incrementing
the counters. Avoid acquiring the lock mutex if the lock wait has
already been resolved. Atomically increment and decrement
srv_stats.n_lock_wait_current_count.

row_insert_for_mysql(), row_update_for_mysql(),
row_update_cascade_for_mysql(): Use the inc() method with the trx->id
as the slot index. This is a non-functional change, just using
inc() instead of add(1).

buf_LRU_get_free_block(): Replace the method add(index, n) with inc().
There is no slot index in the simple_counter.

This was because of two issues:
- thr_multi_lock_after_thr_lock needed to be hit 3 times before go2 could
  be signaled, because 2 of these happened before statistics_update_start
  was reached.
- The original code didn't take into accunt that thr_locks can be executed in
  any random order, which caused sporadic failures when waiting for 1 lock
  of 3, as if the locks where in different order, there would be a dead-lock.
  Fixed by introducing thr_multi_lock_before_thr_lock which is deterministic.
- Some of the test failures where not noticed as the DEBUG_SYNC timeout
  would cause the test to pass (after 300 seconds).

MDEV-11197: TrxInInnoDB::is_aborted(const trx_t*): Assertion `srv_read_only_mode || trx->in_depth > 0' failed

TrxInInnoDB should be constructed to track if a transaction is executing
inside InnoDB code i.e. it is like a gate between Server and InnoDB
::rnd_next() is called from Server and thus construct TrxInInnoDB
also there.

Applied suggested clean-up to TrxInInnoDB class functions enter()
and exit(). Note that exactly original did not work for enter().

The InnoDB temporary tablespace is only usable if innodb_read_only=OFF.
It is useless to create the tablespace in read-only mode, because
CREATE TEMPORARY TABLE is disallowed if innodb_read_only, and nothing
can we written to the temporary tablespace if no temporary tables
can be created.

fix sporadic innodb.truncate_purge_debug failures

because it tests for variables that aren't compiled for Windows,
like --innodb-priority-cleaner

The latest attempted fix for
MDEV-11802 InnoDB purge fails to start when there is work to do
is not complete.

For now, work around the issue by making SHOW ENGINE INNODB STATUS
call srv_wake_purge_thread_if_not_active() to wake up the purge.

MDEV-12679 purge_sys_t::~purge_sys_t(): Assertion `latch.magic_n == 0' failed on --bootstrap (CMAKE_BUILD_TYPE=Debug)

rw_lock_free_func(): Assign lock->magic_n = 0 in debug builds,
because sometimes, the assignment in the explicit destructor call
is being optimized away.
This was verified when using GCC 6.3.0 with -O3 -g -mtune=native
on a Debian GNU/Linux 9.0 system on AMD64.

Use uint32_t for the encryption key_id.

When filling unsigned integer values into INFORMATION_SCHEMA tables,
use the method Field::store(longlong, bool unsigned)
instead of using Field::store(double).

Fix also some miscellanous type mismatch related to ulint (size_t).

The issue was a bad merge of MDEV-12253 from 10.1 to 10.2
in commit f9cc3918.
In that merge, I wrongly assumed that all test file conflicts
for mysql-test/suite/encryption had been properly resolved in
bb-10.2-MDEV-12253 (commit 76aa6be77635c7017459ce33b41c837c9acb606d)
while in fact, some files there had been copied from the 10.1 branch.

This commit is based on a manually done conflict resolution of
the mysql-test/suite/encryption on the same merge, applied to
the current 10.2 branch.

As part of this commit, the test encryption.innodb-bad-key-change4
which was shortly disabled due to MDEV-11336 will be re-enabled again.
(While the test enables innodb_defragment, it does not fail even though
enabling innodb_defragment currently has no effect.)

Apparently openssl ignores CRYPTO_set_mem_functions() in fips mode,
so we cannot detect structure sizes. Don't freak out when
no mallocs were detected.

Tests which fail on Xenial fulltest

When MySQL 5.7.9 was merged to MariaDB 10.2.2, an important
debug assertion was omitted from mlog_write_initial_log_record_low().

mlog_write_initial_log_record_low(): Put back the assertion
mtr_t::is_named_space().

fil_crypt_start_encrypting_space(), fil_crypt_rotate_page():
Call mtr_t::set_named_space() before modifying any pages.

fsp_flags_try_adjust(): Call mtr_t::set_named_space(). This additional
breakage was introduced in the merge of MDEV-11623 from 10.1. It was
not caught because of the missing debug assertion in
mlog_write_initial_log_record_low().

Remove some suppressions from the encryption.innodb-redo-badkey test.

Added a new file ha_xtradb.h where XtraDB parameters are defined. This
file is included in two places to avoid too intrusive change to
ha_innodb.cc that would make future merges harder.

innodb_show_locks_held and innodb_show_verbose_locks should be
implemented (but on different commit).

post-review fixes:
* move all ssl implementation related ifdefs/defines to one file
  (ssl_compat.h)
* work around OpenSSL-1.1 desire to malloc every EVP context by
  run-time checking that context allocated on the stack is big enough
  (openssl.c)
* use newer version of the AWS SDK for OpenSSL 1.1
* use get_dh2048() function as generated by openssl 1.1
  (viosslfactories.c)

Initial support

tested against OpenSSL 1.0.1, 1.0.2, 1.1.0, Yassl and LibreSSL
not working on Windows with native SChannel support, due to wrong cipher
mapping: Latter one requires push of CONC-241 fixes.
Please note that OpenSSL 0.9.8 and OpenSSL 1.1.0 will not work: Even if
the build succeeds, test cases will fail with various errors, especially
when using different tls libraries or versions for client and server.

In windows error message contains .exe.

Reason for this crash is that table->rpl_write_set is NULL. In
Rows_log_event::do_apply_event we set table->rpl_write_set equal to
table->write_set. But we do not set table->rpl_write_set in
Old_rows_log_event::do_apply_event.

This is a backport from 10.2 where it fixes the
cmake -DWITH_ASAN test failure that was mentioned
in commit f9cc3918
(merging MDEV-12253 from 10.1 to 10.2).

fil_parse_write_crypt_data(): If the tablespace is not found,
invoke fil_space_destroy_crypt_data(&crypt_data) to properly
free the created object.

The function buf_read_page_low() invokes fil_io(), which can return
DB_ERROR when the requested page is out of bounds (such as when
restoring a buffer pool dump). The callers should be handling that.

Revert commit db0917f6, because the fix for MDEV-12696
is coming from 5.5 and 10.1 in this merge.

This fixes the cmake -DWITH_ASAN test failure that was mentioned
in commit f9cc3918 (merging
MDEV-12253 from 10.1 to 10.2).

fil_parse_write_crypt_data(): If the tablespace is not found,
invoke fil_space_destroy_crypt_data(&crypt_data) to properly
free the created object.

With this, the test encryption.innodb-redo-badkey still reports
"Missing MLOG_FILE_NAME or MLOG_FILE_DELETE before MLOG_CHECKPOINT"
but does not fail. The misleading message should be corrected,
maybe as part of MDEV-12699.

galera_new_cluster man page and sh typo

Binlog_background_thread does not make a call to set_time(), And when
we call binlog_checkpoint_log_event->write() , we write the wrong timestamp.
In this patch we correct this by calling thd->set_time().