lock_trx_release_locks(): Relax a debug assertion to allow
recovered TRX_STATE_COMMITTED_IN_MEMORY transactions.

trx_commit_in_memory(): Add DEBUG_SYNC instrumentation.

trx_undo_insert_cleanup(): Skip persistent changes if innodb_read_only
is set. This should only happen when a recovered committed transaction
would be cleaned up at shutdown.

        When table is renamed, the InnoDB's dictionary cache didn't
        change the ib_table->data_dir_path accordingly.
        Now it's set to NULL.

Before that line there is call to buf_page_get_gen that could
return block = NULL when decrypting a page fails. However,
we should set error to be != DB_SUCCESS also. In error log
there was error about decompression but in that code there
is one case where error is not set correctly.

add a test that restores the data from a binlog

Fix reinit_io_cache(WRITE_CACHE) with non-zero seek_offset.
Run encryption.tempfiles with and without binlog checksums.

The update was lost during merge.

Timing problem as sometimes table is marked as encrypted but
sometimes we are not sure and table is just marked missing.

Before killing the server, we have to FLUSH TABLES in order to
prevent the corruption of any MyISAM system tables.

PageConverter::adjust_cluster_record(): Instead of writing
the invalid value DB_ROLL_PTR=0, write a value that indicates
a fresh insert, that is, prevents the DB_ROLL_PTR from being
dereferenced in any circumstances.

It can be argued that IMPORT TABLESPACE should actually
update the dict_index_t::trx_id to prevent older transactions
from accessing the table, similar to what I did on table
rebuild in MySQL 5.6.6 in
https://github.com/mysql/mysql-server/commit/03f81a55f221095d397c375afe8a10c8038da339

Use unsigned comparison.

in gcc `-Wno-unsupported-something` will not be an error or even a warning,
so cmake will think the flag is supported. But if there's any other
warning during compilation, for any reason, unknown option will
be a warning too. Or an error when -Werror, even if that "other warning"
would not be an error on itself.

So we need to detect whether `-Wno-unsupported-something` is *really*
supported. Luckily, `-Wunsupported-something` will always fail with an
error.

So, whenever there's a need to detect if -Wno-something is supported,
test -Wsomething instead.

Suppress some messages that are emitted rarely
(when the FIL_PAGE_FILE_FLUSH_LSN of the first page of ibdata1
does not match the latest redo log checkpoint).

Previously, the function could theoretically return an uninitialized
value if the system tablespace contained no data files. It should be
impossible for InnoDB to start up in such scenario.

xtrabackup_init_temp_log(): Remove a redundant variable and limit scope.

The merge omitted some InnoDB and XtraDB conflict resolutions,
most notably, failing to merge the fix of MDEV-12173.

ibuf_merge_or_delete_for_page(), lock_rec_block_validate():
Invoke fil_space_acquire_silent() instead of fil_space_acquire().
This fixes MDEV-12173.

wsrep_debug, wsrep_trx_is_aborting(): Removed unused declarations.

_fil_io(): Remove. Instead, declare default parameters for the XtraDB
fil_io().

buf_read_page_low(): Declare default parameters, and clean up some
callers.

os_aio(): Correct the macro that is defined when !UNIV_PFS_IO.

* use a longer timeout, 10ms is not always enough
* stop waiting as long as the data is read, do not unconditionally
  wait for timeout every time

mysqltest cannot free all memory on exit by design,
so there's no need to check.

mysql frees memory in mysql_end(), so enable memory-leak-on-exit check
only after it was initialized enough to use  mysql_end() - early exits
use my_end().

Do not unwrap view references to keep table info.
(Row-IN subselect does not unwrap items so it does not need fix)

Conflicts:
	storage/innobase/lock/lock0lock.cc
	storage/xtradb/lock/lock0lock.cc
	storage/xtradb/lock/lock0wait.cc
	support-files/mysql.server.sh

Counter for select numbering made stored with the statement (before was global)
So now it does have always accurate value which does not depend on
interruption of statement prepare by errors like lack of table in
a view definition.

only do it in EXTRA_DEBUG builds

don't use internal undocumented OpenSSL functionality