This test was prone to failures for a few reasons, summarized below:

 1) MDEV-32168 introduced “only_running_threads=1” to
slave_stop.inc, which allowed the stop logic to bypass an
attempting-to-reconnect IO thread. That is, the IO thread could
realize the master shutdown in `read_event()`, and thereby call into
`try_to_reconnect()`. This would leave the IO thread up when the
test expected it to be stopped. Fixed by explicitly stopping the
IO thread and allowing an error state, as the above case would
lead to errno 2003.

 2) On slow systems (or those running profiling tools, e.g. MSAN),
the waiting-for-ack transaction can complete before the system
processes the `SHUTDOWN WAIT FOR ALL SLAVES`. There was shutdown
preparation logic in-between the transaction and shutdown itself,
which contributes to this problem. This patch also moves this
preparation logic before the transaction, so there is less to do
in-between the calls.

 3) Changed work-around for MDEV-28141 to use debug_sync instead
of sleep delay, as it was still possible to hit the bug on very
slow systems.

 4) Masked MTR variable reset with disable/enable query log

Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>

A race condition with the SQL thread, where depending on if it was
killed before or after it had executed the fake/generated IGN_GTIDS
Gtid_list_log_event, may or may not update gtid_slave_pos with the
position of the ignored events. Then, the slave would be restarted
while resetting IGNORE_DOMAIN_IDS to be empty, which would result in
the slave requesting different starting locations, depending on
whether or not gtid_slave_pos was updated. And, because previously
ignored events could now be requested and executed (no longer
ignored), their presence would fail the test.

This patch fixes this in two ways. First, to use GTID positions for
synchronization rather than binlog file positions. Then second, to
synchronize the SQL thread’s gtid_slave_pos with the ignored events
before killing the SQL thread.

To consistently reproduce the test failure, the following patch can
be applied:

diff --git a/sql/log_event_server.cc b/sql/log_event_server.cc
index f51f5b7deec..de62233acff 100644
--- a/sql/log_event_server.cc
+++ b/sql/log_event_server.cc
@@ -3686,6 +3686,12 @@ Gtid_list_log_event::do_apply_event(rpl_group_info *rgi)
     void *hton= NULL;
     uint32 i;

+    sleep(1);
+    if (rli->sql_driver_thd->killed || rli->abort_slave)
+    {
+      return 0;
+    }
+

Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>

	JOIN::optimize_inner(), Condition pushdown from HAVING into WHERE
	  not shown in optimizer trace.

When executing a statement of the form
  SELECT AGGR_FN(DISTINCT c1, c2,..,cn) FROM t1,
where AGGR_FN is an aggregate function such as COUNT(), AVG() or SUM(),
and a unique index exists on table t1 covering some or all of the
columns (c1, c2,..,cn), the retrieved values are inherently unique.
Consequently, the need for de-duplication imposed by the DISTINCT
clause can be eliminated, leading to optimization of aggregation
operations.
This optimization applies under the following conditions:
  - only one table involved in the join (not counting const tables)
  - some arguments of the aggregate function are fields
        (not functions/subqueries)

This optimization extends to queries of the form
  SELECT AGGR_FN(c1, c2,..,cn) GROUP BY cx,..cy
when a unique index covers some or all of the columns
(c1, c2,..cn, cx,..cy)

MDEV-33308 CHECK TABLE is modifying .frm file even if --read-only

As noted in commit d0ef1aaf,
MySQL as well as older versions of MariaDB server would during
ALTER TABLE ... IMPORT TABLESPACE write bogus values to the
PAGE_MAX_TRX_ID field to pages of the clustered index, instead of
letting that field remain 0.
In commit 8777458a this field
was repurposed for PAGE_ROOT_AUTO_INC in the clustered index root page.

To avoid trouble when upgrading from MySQL or older versions of MariaDB,
we will try to detect and correct bogus values of PAGE_ROOT_AUTO_INC
when opening a table for the first time from the SQL layer.

btr_read_autoinc_with_fallback(): Add the parameters to mysql_version,max
to indicate the TABLE_SHARE::mysql_version of the .frm file and the
maximum value allowed for the type of the AUTO_INCREMENT column.
In case the table was originally created in MySQL or an older version of
MariaDB, read also the maximum value of the AUTO_INCREMENT column from
the table and reset the PAGE_ROOT_AUTO_INC if it is above the limit.

dict_table_t::get_index(const dict_col_t &) const: Find an index that
starts with the specified column.

ha_innobase::check_for_upgrade(): Return HA_ADMIN_FAILED if InnoDB
needs upgrading but is in read-only mode. In this way, the call to
update_frm_version() will be skipped.

row_import_autoinc(): Adjust the AUTO_INCREMENT column at the end of
ALTER TABLE...IMPORT TABLESPACE. This refinement was suggested by
Debarun Banerjee.

The changes outside InnoDB were developed by Michael 'Monty' Widenius:

Added print_check_msg() service for easy reporting of check/repair messages
in ENGINE=Aria and ENGINE=InnoDB.
Fixed that CHECK TABLE do not update the .frm file under --read-only.
Added 'handler_flags' to HA_CHECK_OPT as a way for storage engines to
store state from handler::check_for_upgrade().

Reviewed by: Debarun Banerjee

This patch fixes the issue with passing the DEFAULT or IGNORE values to
positional parameters for some kind of SQL statements to be executed
as prepared statements.

The main idea of the patch is to associate an actual value being passed
by the USING clause with the positional parameter represented by
the Item_param class. Such association must be performed on execution of
UPDATE statement in PS/SP mode. Other corner cases that results in
server crash is on handling CREATE TABLE when positional parameter
placed after the DEFAULT clause or CALL statement and passing either
the value DEFAULT or IGNORE as an actual value for the positional parameter.
This case is fixed by checking whether an error is set in diagnostics
area at the function pack_vcols() on return from the function pack_expression()

MDEV-15703: Crash in EXECUTE IMMEDIATE 'CREATE OR REPLACE TABLE t1 (a INT DEFAULT ?)' USING DEFAULT, UBSAN runtime error: member call on null pointer of type 'struct TABLE_LIST' in Item_param::save_in_field

This is the prerequisite patch to refactor the method
  Item_default_value::fix_fields.
The former implementation of this method was extracted and placed
into the standalone function make_default_field() and the method
Item_default_value::tie_field(). The motivation for this modification
is upcoming changes for core implementation of the task MDEV-15703
since these functions will be used from several places within
the source code.

row_discard_tablespace(): Do not invoke dict_index_t::clear_instant_alter()
because that would corrupt any adaptive hash index entries in the table.

row_import_for_mysql(): Invoke dict_index_t::clear_instant_alter()
after detaching any adaptive hash index entries.

Recording both is useful on a replication relay when the backup
can be used to replace the server, or ack as a new replica to the
server.

If an option=2, commented is selected, allow the alternate option
to exist.

This still disables --dump-slave=1 --master-data=1 as having the
a CHANGE MASTER TO and START SLAVE on different positions would be
confusing and dangerious to the try to execute the output. The
previous behaviour of silently disabling --master-data occurs in
this case.

The commented code related to --dump-slave/--master-data is greatly
expanded for human consumption.

A redundant opt_slave_data= 0 was removed from get_opts. If
--dump-slave=1 or 2, then the only possible value of --master-data
is a valid one.

Re-order to preference gtid based replication.

Based of code from Elena Stepanova.

Review by: Brandon Nesterenko and Anel Husakovic

This will make it easier to show changes.

If we fail to open a tablespace while looking for FILE_CHECKPOINT, we
set the corruption flag. Specifically, if encryption key is missing, we
would not be able to open an encrypted tablespace and the flag could be
set. We miss checking for this flag and report "Missing FILE_CHECKPOINT"

Address review comment to improve the test. Flush pages before starting
no-checkpoint block. It should improve the number of cases where the
test is skipped because some intermediate checkpoint is triggered.

Fix inconsistent definition of PERFORMANCE_SCHEMA.REPLICATION_APPLIER_STATUS.COUNT_TRANSACTIONS_RETRIES column

This column (`COUNT_TRANSACTIONS_RETRIES`) is defined as `BIGINT UNSIGNED`
(64-bit unsigned integer) in the user-visible SQL definition:
https://github.com/MariaDB/server/blob/182ff21ace34ea4f00fb5b66689b172323d91f99/storage/perfschema/table_replication_applier_status.cc#L66

    "COUNT_TRANSACTIONS_RETRIES BIGINT unsigned not null comment 'The number of retries that were made because the replication SQL thread failed to apply a transaction.',"

And its value is internally set/updated using the `set_field_ulonglong`
function:
https://github.com/MariaDB/server/blob/182ff21ace34ea4f00fb5b66689b172323d91f99/storage/perfschema/table_replication_applier_status.cc#L231-L233

    case 3: /* total number of times transactions were retried */
      set_field_ulonglong(f, m_row.count_transactions_retries);
      break;

… but the structure where it is stored allocates only `ulong` for it:
https://github.com/MariaDB/server/blob/182ff21ace34ea4f00fb5b66689b172323d91f99/storage/perfschema/table_replication_applier_status.h#L62

    ulong count_transactions_retries;

As a result of this inconsistency:

1. On any platform where `ulong` is `uint32_t` and `ulonglong` is `uint64_t`,
   setting this value would corrupt the 4 bytes of memory *following* the 4
   bytes actually allocated for it.

   Likely this problem was never noticed because this is the final element in
   the structure, and the structure is padded by the compiler to prevent
   memory corruption errors.

2. On any BIG-ENDIAN platform where `ulong` is `uint32_t` and `ulonglong`
   is `uint64_t`, reading back the value of this column will result in
   total garbage.

   Likely this problem was never noticed because MariaDB has not been
   tested on 32-bit big-endian platforms.

In order not to affect the user-visible/SQL definition of this column, the
correct way to fix this issue is to change it to `ulonglong` in the
structure definition.  See
https://github.com/MariaDB/server/pull/2763/files#r1329110832 for the
original identification and discussion of this issue.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the BSD-new
license. I am contributing on behalf of my employer Amazon Web Services

As was done in dc771113 for `support-files/CMakeLists.txt`
Do not rely on existence of `CMakeFiles/${target}.dir` directory
existence. It is not there for custom targets in Ninja build.

This regression was introduced in #1131 which likely copied the pattern
from e79e8406 before that regression was addressed in dc771113.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services.

mariadb-backup with --prepare option could result in empty redo log
file. When --prepare is followed by --prepare --export, we exit early
in srv_start function without opening the ibdata1 tablespace. Later
while trying to read rollback segment header page, we hit the debug
assert which claims that the system space should already have been
opened.

There are two assert cases here.

Issue-1: System tablespace object is not there in fil space hash i.e.
srv_sys_space.open_or_create() is not called.

Issue-2: The system tablespace data file ibdata1 is not opened i.e.
fil_system.sys_space->open() is not called.

Fix: For empty redo log and restore operation, open system tablespace
before returning.

THE FIX MUST NOT BE MERGED TO 10.6+, BECAUSE 10.6+ IS NOT AFFECTED!

The test is waiting for delete-marked record purging. But this does not
happen under the following conditions:

1. "START TRANSACTION WITH CONSISTENT SNAPSHOT" - is active, has not
been rolled back yet
2. "DELETE FROM t WHERE b = 20 # trx_1" - is committed
3. "INSERT INTO t VALUES(10, 20) # trx_2" - hanging on
"ib_after_row_insert" sync point, waiting for "first_ins_cont" signal
4. "DELETE FROM t WHERE b = 20 # trx_3" - blocked on delete-marked by
trx_1 record, waiting for trx_2
5. connection "default" is waiting on
'now WAIT_FOR row_purge_del_mark_finished'

purge_coordinator_callback_low() sets

purge_state.m_history_length= srv_do_purge(&n_total_purged);

even if nothing was purged, like in our case. Nothing was purged because
transaction with consistent snapshot was still alive during purging
procedure.

Then purge_coordinator_timer_callback() does not wake purge thread if
the following condition is true:

purge_state.m_history_length == trx_sys.rseg_history_len

The above condition is true for our case, because we are waiting for
delete-marked record purging, and trx_sys.rseg_history_len does not
grow.

Only 10.5 is affected, because there is no such condition in 10.6, i.e.
purge thread is woken up even if history size was not changed during
purge coordinator thread suspending.

The easiest way to fix it is just to remove the test from 10.5.

- Failed to reset the innodb_fil_make_page_dirty_debug variable in
innodb_saved_page_number_debug_basic test case.

Without an OS error it could one of the many errors from write.

MDEV-18288 Transportable Tablespaces leave AUTO_INCREMENT in mismatched state, causing INSERT errors in newly imported tables when .cfg is not used.

During import, if cfg file is not specified, we don't update the autoinc
field in innodb dictionary object dict_table_t. The next insert tries to
insert from the starting position of auto increment and fails.

It can be observed that the issue is resolved once server is restarted
as the persistent value is read correctly from PAGE_ROOT_AUTO_INC from
index root page. The patch fixes the issue by reading the the auto
increment value directly from PAGE_ROOT_AUTO_INC during import if cfg
file is not specified.

Test Fix:

1. import_bugs.test: Embedded mode warning has absolute path. Regular
expression replacement in test.

2. full_crc32_import.test: Table level auto increment mismatch after
import. It was using the auto increment data from the table prior to
discard and import which is not right. This value has cached auto
increment value higher than the actual inserted value and value stored
in PAGE_ROOT_AUTO_INC. Updated the result file and added validation for
checking the maximum value of auto increment column.

In commit 179424db the file lowercase_table2.result was made executable
for no known reason, most likely just a mistake. Test result files
definitely should not be executable.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.

This bug led to wrong result sets returned by the second execution of
prepared statements from selects using mergeable derived tables pushed
into external engine. Such derived tables are always materialized. The
decision that they have to be materialized is taken late in the function
mysql_derived_optimized(). For regular derived tables this decision is
usually taken at the prepare phase. However in some cases for some derived
tables this decision is made in mysql_derived_optimized() too. It can be
seen in the code of mysql_derived_fill() that for such a derived table it's
critical to change its translation table to tune it to the fields of the
temporary table used for materialization of the derived table and this
must be done after each refill of the derived table. The same actions are
needed for derived tables pushed into external engines.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

@@ -314,7 +314,7 @@
 select straight_join * from t0, part ignore index (primary)
 where p_partkey=t0.a and p_size=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	6	Using where
 1	SIMPLE	part	eq_ref	i_p_size	i_p_size	9	const,dbt3_s001.t0.a	1

Variant#3: moved the logic out of create_key_parts_for_pseudo_indexes

Range Analyzer (get_mm_tree functions) can only process up to MAX_KEY=64
indexes. The problem was that calculate_cond_selectivity_for_table used
it to estimate selectivities for columns, and since a table can
have > MAX_KEY columns, would invoke Range Analyzer with more than MAX_KEY
"pseudo-indexes".

Fixed by making calculate_cond_selectivity_for_table() to run Range
Analyzer with at most MAX_KEY pseudo-indexes. If there are more
columns to process, Range Analyzer will be invoked multiple times.

Also made this change:
-    param.real_keynr[0]= 0;
+    MEM_UNDEFINED(&param.real_keynr, sizeof(param.real_keynr));

Range Analyzer should have no use on real_keynr when it is run with
pseudo-indexes.

mariadb-backup:

Adding a function get_os_user() to detect the OS user name
if the user name is not specified, to make mariadb-backup:
- work like MariaDB client tools work
- match its --help page, which says:

  -u, --user=name This option specifies the username used when
  connecting to the server, if that's not the current user.

MDEV-33355 Add a Galera-2-node-to-MariaDB replication MTR test cloning the slave with mariadb-backup

Replication from a 2-node Galera cluster to a regular MariaDB server.
Cloning the slave using mariadb-backup.

This bug was fixed by the patch for bug MDEV-30706.
Only a test case is added in this commit.

According to the standard, the autoincrement column (i.e. *identity
column*) should be advanced each insert implicitly made by
UPDATE/DELETE ... FOR PORTION.

This is very unconvenient use in several notable cases. Concider a
WITHOUT OVERLAPS key with an autoinc column:
id int auto_increment, unique(id, p without overlaps)

An update or delete with FOR PORTION creates a sense that id will remain
unchanged in such case.

The standard's IDENTITY reminds MariaDB's AUTO_INCREMENT, however
the generation rules differ in many ways. For example, there's also a
notion autoincrement index, which is bound to the autoincrement field.

We will define our own generation rule for the PORTION OF operations
involving AUTO_INCREMENT:
* If an autoincrement index contains WITHOUT OVERLAPS specification, then
a new value should not be generated, otherwise it should.

Apart from WITHOUT OVERLAPS there is also another notable case, referred
by the reporter - a unique key that has an autoincrement column and a field
from the period specification:
  id int auto_increment, unique(id, s), period for p(s, e)

for this case, no exception is made, and the autoincrementing rules will be
proceeded accordung to the standard (i.e. the value will be advanced on
implicit inserts).

test disabled, until fixed

Reason:
======
undo_space_dblwr test case fails if the first page of undo
tablespace is not flushed before restart the server. While
restarting the server, InnoDB fails to detect the first
page of undo tablespace from doublewrite buffer.

Fix:
===
Use "ib_log_checkpoint_avoid_hard" debug sync point
to avoid checkpoint and make sure to flush the
dirtied page before killing the server.

innodb_make_page_dirty(): Fails to set
srv_fil_make_page_dirty_debug variable.