This reverts commit e731a283.

A crash occurred during the test stress.ddl_innodb when
fil_delete_tablespace() for DROP TABLE was waiting in
fil_check_pending_operations() and a purge thread for handling
an earlier DROP INDEX was attempting to load the index root page
in btr_free_if_exists() and btr_free_root_check(). The function
buf_page_get_gen() would write out several times
"trying to read...being-dropped tablespace"
before giving up and committing suicide.

It turns out that during any page access in btr_free_if_exists(),
fil_space_t::set_stopping() could have been invoked by
fil_check_pending_operations(), as part of dropping the tablespace.
Preventing this race condition would require extensive changes
to the allocation code or some locking mechanism that would ensure
that we only set the flag if btr_free_if_exists() is not in progress.

Either way, that could be a too risky change in a GA release.
Because MDEV-24589 is not strictly necessary in the 10.5 release
series and it only is a requirement for MDEV-25180 in a later
major release, we will revert the change from 10.5.

Issue:- Since there is no waiting for the actual disconnection of the con_tmp
(which does XA prepare of test1), We can have a issue when test1 is not
prepared and we are calling rollback on test1 , giving XAER_NOTA: Unknown XID
error

Solution:- Wait for the complete disconnection of con_tmp

buf_resize_callback(): Correct an invalid assertion, and enable
the assertion in debug builds only.

Between buf_resize_start() and buf_resize_shutdown(),
srv_shutdown_state must be less than SRV_SHUTDOWN_CLEANUP.

The incorrect assertion had been introduced in
commit 5e62b6a5 (MDEV-16264).
As a result, the server could crash if shutdown was initiated
concurrently with initiating a change of innodb_buffer_pool_size.

		to mysql interpreter

InnoDB returns uninitialized statistics to mysql interpreter
when background thread is opening the table. So it leads to
assertion failure. In that case, InnoDB avoid sending
innodb statistics information to mysql interpreter.

node->index was NULL.
But it's possible to get dict_table_t* from another source.

There was race between a committing transaction and the following in binlog
order FLUSH LOGS that could create a 2nd Binlog checkpoint (BCP) event
in the new file *before* the first logged-in-old-binlog transaction gets committed in
Innodb. That would cause the transaction loss at recovery, should
the server stop right after the BCP.

The race is tackled by enforcing the necessary set of mutexes to be acquired
by FLUSH-LOGS handler in the correct order (of the group commit leader
pattern).

Note, there remain two cases where a similar race is still possible:
  - the above race as it is when the server is run with ("unlikely")
    non-default `--binlog-optimize-thread-scheduling=0` (MDEV-24530), and
  - at unlikely event of bin-logging of Incident event (MDEV-24531) that
    also triggers binlog rotation,
    in both cases though with lesser chances after the current fixes.

As suggested by Vladislav Vaintroub, we must shift a constant of
unsigned long, not int.

Closes #1811

Since it ended up being a plain text file rather than a script
(post-fix for MDEV-25288)
Also removed main-test_sql_discovery.create from the list,
as a workaround for MDEV-25384. The bug only affects 10.3+,
but it will be simpler if 10.2 part of the tests is the same
in all branches

... to run upon building/packaging of MariaDB server

Eliminate a memory leak when init can fail by forgetting to delete the
Event_queue_element_for_exec object.

PROBLEM
-------

1. The customer had presented a stack which had many threads waiting on
   multiple mutexes like LOCK_Status, srv_innodb_monitor_mutex,  ibuf_mutex etc.
2. The root cause was that the AHI latch was held in S (shared) mode by the a thread which was
   doing a truncate of a large table .
3. There was another thread which was trying to acquire the AHI latch in X (exclusive) mode
4. With our lock implementation any thread requesting a X lock ,blocks rest of the threads
   requesting S(shared) locks,this caused many threads to wait for this shared lock.
5. The main reason why we hold the latches in truncate is to avoid disabling of AHI
   during truncate

FIX

The easiest way to compile and test the server with UBSAN is to run:
./BUILD/compile-pentium64-ubsan
and then run mysql-test-run.
After this commit, one should be able to run this without any UBSAN
warnings. There is still a few compiler warnings that should be fixed
at some point, but these do not expose any real bugs.

The 'special' cases where we disable, suppress or circumvent UBSAN are:
- ref10 source (as here we intentionally do some shifts that UBSAN
  complains about.
- x86 version of optimized int#korr() methods. UBSAN do not like unaligned
  memory access of integers.  Fixed by using byte_order_generic.h when
  compiling with UBSAN
- We use smaller thread stack with ASAN and UBSAN, which forced me to
  disable a few tests that prints the thread stack size.
- Verifying class types does not work for shared libraries. I added
  suppression in mysql-test-run.pl for this case.
- Added '#ifdef WITH_UBSAN' when using integer arithmetic where it is
  safe to have overflows (two cases, in item_func.cc).

Things fixed:
- Don't left shift signed values
  (byte_order_generic.h, mysqltest.c, item_sum.cc and many more)
- Don't assign not non existing values to enum variables.
- Ensure that bool and enum values are properly initialized in
  constructors.  This was needed as UBSAN checks that these types has
  correct values when one copies an object.
  (gcalc_tools.h, ha_partition.cc, item_sum.cc, partition_element.h ...)
- Ensure we do not called handler functions on unallocated objects or
  deleted objects.
  (events.cc, sql_acl.cc).
- Fixed bugs in Item_sp::Item_sp() where we did not call constructor
  on Query_arena object.
- Fixed several cast of objects to an incompatible class!
  (Item.cc, Item_buff.cc, item_timefunc.cc, opt_subselect.cc, sql_acl.cc,
   sql_select.cc ...)
- Ensure we do not do integer arithmetic that causes over or underflows.
  This includes also ++ and -- of integers.
  (Item_func.cc, Item_strfunc.cc, item_timefunc.cc, sql_base.cc ...)
- Added JSON_VALUE_UNITIALIZED to json_value_types and ensure that
  value_type is initialized to this instead of to -1, which is not a valid
  enum value for json_value_types.
- Ensure we do not call memcpy() when second argument could be null.
- Fixed that Item_func_str::make_empty_result() creates an empty string
  instead of a null string (safer as it ensures we do not do arithmetic
  on null strings).

Other things:

- Changed struct st_position to an OBJECT and added an initialization
  function to it to ensure that we do not copy or use uninitialized
  members. The change to a class was also motived that we used "struct
  st_position" and POSITION randomly trough the code which was
  confusing.
- Notably big rewrite in sql_acl.cc to avoid using deleted objects.
- Changed in sql_partition to use '^' instead of '-'. This is safe as
  the operator is either 0 or 0x8000000000000000ULL.
- Added check for select_nr < INT_MAX in JOIN::build_explain() to
  avoid bug when get_select() could return NULL.
- Reordered elements in POSITION for better alignment.
- Changed sql_test.cc::print_plan() to use pointers instead of objects.
- Fixed bug in find_set() where could could execute '1 << -1'.
- Added variable have_sanitizer, used by mtr.  (This variable was before
  only in 10.5 and up).  It can now have one of two values:
  ASAN or UBSAN.
- Moved ~Archive_share() from ha_archive.cc to ha_archive.h and marked
  it virtual. This was an effort to get UBSAN to work with loaded storage
  engines. I kept the change as the new place is better.
- Added in CONNECT engine COLBLK::SetName(), to get around a wrong cast
  in tabutil.cpp.
- Added HAVE_REPLICATION around usage of rgi_slave, to get embedded
  server to compile with UBSAN. (Patch from Marko).
- Added #ifdef for powerpc64 to avoid a bug in old gcc versions related
  to integer arithmetic.

Changes that should not be needed but had to be done to suppress warnings
from UBSAN:

- Added static_cast<<uint16_t>> around shift to get rid of a LOT of
  compiler warnings when using UBSAN.
- Had to change some '/' of 2 base integers to shift to get rid of
  some compile time warnings.

Reviewed by:
- Json changes: Alexey Botchkov
- Charset changes in ctype-uca.c: Alexander Barkov
- InnoDB changes & Embedded server: Marko Mäkelä
- sql_acl.cc changes: Vicențiu Ciorbaru
- build_explain() changes: Sergey Petrunia

* Disallow setting wsrep_on = 1 if wsrep_provider is unset. Also, move
  wsrep_on_basic from sys_vars to wsrep suite: this test now requires
  to run with wsrep_provider set
* Disallow setting @@session.wsrep_on = 1 when @@global.wsrep_on = 0
* Handle the case where a new connection turns @@global.wsrep_on from
  off to on. In this case we would miss a call to wsrep_open, causing
  unexpected states in wsrep::client_state (causing assertions).
* Disable wsrep.MDEV-22443 because it is no longer possible to enable
  wsrep_on, if server is started with wsrep_provider='none'
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

MDEV-22757 Assertion !binlog || exist_hton_without_prepare' failed in MYSQL_BIN_LOG::unlog_xa_prepare

The assert fired falsely having not captured two more not apparent
possiblities in its condition.

They are masked out hton error out of REPLACE execution (so at later xa-prepare
that engine is still present as read-write) and a prepare-capable engine
which also may not be an actual participant in the xa transation. That
engine, such as SEQUENCE, though does create its own event block.

This was caused by MDEV-23634, which disabled index optimization for
index != constant.

* Table should have primary key
* Enable wsrep_sync_wait before final selects
* Enable autocommit before final selects.
* Fix joiner monitoring in case of mysqldump.
* Add wait_conditions to stabilize

When dropped all user key-parts we also drop key-parts of implicit system fields.

This patch sets the proper name resolution context for outer references
used in a subquery from an ON clause. Usually this context is more narrow
than the name resolution context of the parent select that were used before
this fix.
This fix revealed another problem that concerned ON expressions used in
from clauses of specifications of derived tables / views / CTEs. The name
resolution outer context for such ON expression must be set to NULL to
prevent name resolution beyond the derived table where it is used.
The solution to resolve this problem applied in sql_derived.cc was provided
by Sergei Petrunia <sergey@mariadb.com>.

The change in sql_parse.cc is not good for 10.4+. A corresponding diff for
10.4+ will be provided in JIRA entry for this bug.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

It seems some overly tolerant compilers (gcc) allow the structure
of IO_CACHE that is defined differently in libmaria to have
members equalivance to the iocache in mysys.

More strict Solaris compilers recognise that rc_pos really
isn't a structure member and won't compile.

Make Item_subselect::walk() walk the ON expressions, too.

This reverts commit f26e3259.

MDEV-22255 SIGABRT: Assertion `id' failed in trx_write_trx_id on INSERT | Assertion `id > 0' failed in trx_write_trx_id | Assertion `val > 0' failed in row_upd_index_entry_sys_field | Assertion `thr_get_trx(thr)->id || index->table->no_rollback()' failed.

InnoDB purge thread locks the root page of clustered index
while accessing the undo log records and later same thread
tries to open the table, initialize statistics and tries
to lock the clustered index root page while doing virtual
column computation.

Solution:
=========
InnoDB should prevent statistics initialization when the
table is being opened by purge thread

MDEV-25425 Useless message "If the mysqld execution user is authorized page cleaner thread priority can be changed."

On startup, InnoDB tried to increase the priority of the page cleaner
thread. This would usually fail, resulting in a server log message.

When the page cleaner code was refactored in MDEV-23855, the throughput
and latency were greatly improved even when the
buf_flush_page_cleaner thread always ran the same priority with other
threads in our benchmarks.

So, this code should have no benefit in MariaDB Server 10.5.7 or later.

Besides, starting with MariaDB Server 10.5, the executable is called
mariadbd, not mysqld.

When a column is added to an non-empty table, existing rows will have
a column's default value for existing rows. Or a "zero value" if the
column has no default.

But this check should be skipped when an existing column is altered.

Trigger `socket.ssl_reload` when FLUSH SSL is issued. To triger reloading
of certificate, key and CA, files needs to be physically changed.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>