Marko reported DBUG_ASSERT from dict_stats_shutdown().

destroy_background_thd() does not like when current_thd is set.
In galera, it can be the case, dict_stats_shutdown() can be called from
user thread, to stop and later restart stats recalculations.

The merge e95bba9c missed it

Attempting to set a SAVEPOINT when one of the involved storage engines
does not support savepoints, raises an error, and results in statement
rollback. If Galera is enabled with binlog emulation, the above
scenario was not handled correctly, and resulted in cluster wide
inconsistency.

The problem was in wsrep_register_binlog_handler(), which is called
towards the beginning of SAVEPOINT execution. This function is
supposed to mark the beginning of statement position in trx cache
through `set_prev_position()`. However, it did so only on condition
that `get_prev_position()` returns `MY_OFF_T_UNDEF`.
This before statement position is typically reset to undefined at the
end of statement in `binlog_commit()` / `binlog_rollback()`.
However that's not the case with Galera and binlog emulation, for
which binlog commit / rollback hooks are not called due to the
optimization that avoids internal 2PC (MDEV-16509).
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

This commit fixes GTID inconsistency which was injected by mariabackup SST.
Donor node now writes new info file: donor_galera_info, which is streamed
along the mariabackup donation to the joiner node. The donor_galera_info
file contains both GTID and gtid domain_id, and joiner will use these to
initialize the GTID state.

Commit has new mtr test case: galera_3nodes.galera_gtid_consistency, which
exercises potentially harmful mariabackup SST scenarios. The test has also
scenario with IST joining.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

Changes to be committed:
	modified:   mysql-test/suite/galera/r/MW-388.result
	modified:   mysql-test/suite/galera/r/MW-86-wait1.result
	modified:   mysql-test/suite/galera/r/MW-86-wait8.result
	modified:   mysql-test/suite/galera/r/galera_myisam_autocommit.result
	modified:   mysql-test/suite/galera/r/galera_var_retry_autocommit.result
	modified:   mysql-test/suite/galera/t/galera_myisam_autocommit.test

These tests are run only using debug Galera library and changes are
only test related.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

If recalc_pool is not empty, dict_stats needs to be rescheduled.

Also revert aff5ed39

Use static dict_stats_thd instead of creating/destroying it every time
function is called.

dict_stats_schedule() is executed for --innodb-force-recovery=3+,
but timer is not created.

Timer has internal synchronization, so that calling
set_time concurrently is not a problem.

ASAN uses *a lot* more stack. use not_asan.inc for tests
that recursively put a lot of data on the stack

In spider_db_mbase_util::print_item_func(), if the sql item_func has
an UNKNOWN_FUNC type, by default the spider group by handler (gbh)
transform infix to prefix. But regexp should remain infix, so we add
an if condition to account for this.

Improve test case to wait until cluster membership is
correct.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

This reverts commit ddd8a908 (additional correction required)

This patch fixes cases where a transaction caused empty writeset to be
replicated. This could happen in the case where a transaction executes
a statement that initially manages to modify some data and therefore
appended keys some for  certification. The statement is however rolled
back at some later stage due to some error (for example, a duplicate
key error). After statement rollback the transaction is still alive,
has no other changes. When committing such transaction, an empty
writeset was replicated through Galera.

The fix is to avoid calling into commit hook only when transaction
has appended one or keys for certification *and* has some data in
binlog cache to replicate. Otherwise, the commit is considered empty,
and goes through usual empty commit path.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

Remove DB_LOCK_WAIT return code check as it should have been resolved to
one of the other errors by that point.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

Changes to be committed:

	modified:   mysql-test/suite/wsrep/disabled.def
	deleted:    mysql-test/suite/wsrep/r/MDEV-22443.result
	deleted:    mysql-test/suite/wsrep/r/MDEV-23092.result
	deleted:    mysql-test/suite/wsrep/r/mdev_6832.result
	deleted:    mysql-test/suite/wsrep/r/wsrep_variables_no_provider.result
	deleted:    mysql-test/suite/wsrep/t/MDEV-22443.cnf
	deleted:    mysql-test/suite/wsrep/t/MDEV-22443.test
	deleted:    mysql-test/suite/wsrep/t/MDEV-23092.cnf
	deleted:    mysql-test/suite/wsrep/t/MDEV-23092.test
	deleted:    mysql-test/suite/wsrep/t/mdev_6832.cnf
	deleted:    mysql-test/suite/wsrep/t/mdev_6832.test
	deleted:    mysql-test/suite/wsrep/t/wsrep_variables_no_provider.cnf
	deleted:    mysql-test/suite/wsrep/t/wsrep_variables_no_provider.test

These test cases used feature not available anymore.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

trx_purge_truncate_history(): If a fast shutdown has been initiated,
disregard innodb_undo_log_truncate=ON and return.

The previous patch for MDEV-10653 changes the rpl_parallel::workers_idle()
function to use Relay_log_info::last_inuse_relaylog to check for idle
workers. But the code was missing a NULL check. Also, there was one place
during SQL slave thread start which was missing mutex synchronisation when
updating inuse_relaylog.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

The error-injection inject_mdev8031 simulates a deadlock kill in a specific
place, by setting killed_for_retry to RETRY_KILL_KILLED directly. If a real
deadlock kill triggers at the same time, it is possible for the thread to
complete its transaction retry and set rgi_slave to NULL before the real
readlock kill can complete in the background. This will cause a segfault
due to null-pointer access.

Fix by changing the error injection to do a real background deadlock kill,
which ensures that the thread will wait for any pending background kills to
complete.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Item::val_str() sets the Item::null_value flag, so call it before checking
the flag, not after.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

trx_purge_truncate_history(): Release buf_pool.flush_list_mutex
and 'dummily' acquire and release buf_pool.mutex before starting
a rescan of buf_pool.flush_list, to ensure that
the buf_flush_page_cleaner thread (which may be holding buf_pool.mutex)
will be able to proceed.

This fixes up commit 5dbe7a8c (MDEV-32757).

Tested by: Axel Schwenke (on Ubuntu 18.04 and Ubuntu 20.04)
Reviewed by: Vladislav Lesin

This commit addresses the file leakage problem encountered with the mysql_upgrade --check-if-upgrade-is-needed command.

buf_read_ahead_linear(): Suppress a warning of comparing potentially
uninitialized FIL_PAGE_PREV and FIL_PAGE_NEXT fields.

it can be invoked with ms=0. In that case dict_stats_func is
invoked immediately, it calls dict_stats_process_entry_from_recalc_pool()
which at the end might try to call dict_stats_schedule() again to
queue another recalc. And it can happen that the first
dict_stats_schedule(0) call didn't release dict_stats_mutex yet,
so the second dict_stats_schedule() won't queue a recalc. And as a
result the table won't have its stats recalculated at all, not now,
not later.

This causes innodb.innodb_stats_auto_recalc to fail sporadically.

This commit doesn't fix it but makes it less likely to occur which happens
to be enough for the test to pass. Proper fix is coming soon.

use signal_ddl_recovery_done callback for that.

also make the server to call signal_ddl_recovery_done() when loading
plugins at run-time (so that plugins would't need to detect that
on their own)

trx_purge_truncate_history(): Release buf_pool.flush_list_mutex
before starting a rescan of buf_pool.flush_list, to ensure that
the buf_flush_page_cleaner thread (which may be holding buf_pool.mutex)
will be able to proceed.

This fixes up commit a0f02f74 (MDEV-32757).

Tested by: Axel Schwenke
Reviewed by: Vladislav Lesin

see also 4eca64e3