During graceful shutdowns, client connections are closed and
eventually and THD::awake() acquires LOCK_thd_data mutex which is
required later on in wsrep_thd_is_aborting(). Make sure LOCK_thd_data
is acquired, even if global wsrep_on is disabled.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Some DDL statements appear to acquire MDL locks for a table referenced by
foreign key constraint from the actual affected table of the DDL statement.
OPTIMIZE, REPAIR and ALTER TABLE belong to this class of DDL statements.

Earlier MariaDB version did not take this in consideration, and appended
only affected table in the certification key list in write set.
Because of missing certification information, it could happen that e.g.
OPTIMIZE table for FK child table could be allowed to apply in parallel
with DML operating on the foreign key parent table, and this could lead to
unhandled MDL lock conflicts between two high priority appliers (BF).

The fix in this patch, changes the TOI replication for OPTIMIZE, REPAIR and
ALTER TABLE statements so that before the execution of respective DDL
statement, there is foreign key parent search round. This FK parent search
contains following steps:
* open and lock the affected table (with permissive shared locks)
* iterate over foreign key contstraints and collect and array of Fk parent
  table names
* close all tables open for the THD and release MDL locks
* do the actual TOI replication with the affected table and FK parent
  table names as key values

The patch contains also new mtr test for verifying that the above mentioned
DDL statements replicate without problems when operating on FK child table.
The mtr test scenario #1, which can be used to check if some other DDL
(on top of OPTIMIZE, REPAIR and ALTER) could cause similar excessive FK
parent table locking.
Reviewed-by: Aleksey Midenkov <aleksey.midenkov@mariadb.com>
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Prepared statements which were run over binary protocol crashed
a server if the statement did not have CF_PS_ARRAY_BINDING_OPTIMIZED
flag and the statement was executed in bulk mode and a BF abort occrurred.
This was because the bulk execution resulted in several statements without
calling wsrep_after_statement() between, which confused wsrep transaction
state tracking.

As a fix, call wsrep_after_statement() in bulk loop after each execution
if CF_PS_ARRAY_BINDING_OPTIMIZED is not set.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

instant_alter_column_possible(): Relax a too strict debug assertion.
The existence of an index stub or a corrupted index on virtual columns
does not imply that virtual columns exist.

C++11 is allowed only starting with MariaDB Server 10.4.

This follows up commit
commit 94a520dd and
commit 7c5519c1.

After these changes, the default test suites on a
cmake -DWITH_UBSAN=ON build no longer fail due to passing
null pointers as parameters that are declared to never be null,
but plenty of other runtime errors remain.

This was missed in commit d6ea03fa.

Add --system={all, users, plugins, udfs, servers, stats, timezones}

This will dump system information from the server in
a logical form like:
* CREATE USER
* GRANT
* SET DEFAULT ROLE
* CREATE ROLE
* CREATE SERVER
* INSTALL PLUGIN
* CREATE FUNCTION

"stats" is the innodb statistics tables or EITS and
these are dumped as INSERT/REPLACE INTO statements
without recreating the table.

"timezones" is the collection of timezone tables
which are important to transfer to generate identical
results on restoration.

Two other options have an effect on the SQL generated by
--system=all. These are mutually exclusive of each other.
* --replace
* --insert-ignore

--replace will include "OR REPLACE" into the logical form
like:
* CREATE OR REPLACE USER ...
* DROP ROLE IF EXISTS (MySQL-8.0+)
* CREATE OR REPLACE ROLE ...
* UNINSTALL PLUGIN IF EXISTS (10.4+) ... (before INSTALL PLUGIN)
* DROP FUNCTION IF EXISTS (MySQL-5.7+)
* CREATE OR REPLACE [AGGREGATE] FUNCTION
* CREATE OR REPLACE SERVER

--insert-ignore uses the construct " IF NOT EXISTS" where
supported in the logical syntax.

'CREATE OR REPLACE USER' includes protection against
being run as the same user that is importing the mysqldump.

Includes experimental support for dumping mysql-5.7/8.0
system tables and exporting logical SQL compatible with MySQL.

Updates mysqldump man page, including this information and
(removing obsolute bug reference)

Reviewed-by: anel@mariadb.org

Per b9f3f068, mysql_system_tables_data.sql creates
a mysql_native_password with a salted hash of "invalid" so that `set password`
will detect a native password can be applied:.

SHOW CREATE USER; diligently uses this value in its output
generating the SQL:

   MariaDB [(none)]> show create user;

   +---------------------------------------------------------------------------------------------------+
   | CREATE USER for dan@localhost                                                                     |
   +---------------------------------------------------------------------------------------------------+
   | CREATE USER `dan`@`localhost` IDENTIFIED VIA mysql_native_password USING 'invalid' OR unix_socket |
   +---------------------------------------------------------------------------------------------------+

Attempting to execute this before this patch results in:

  MariaDB [(none)]>  CREATE USER `dan2`@`localhost` IDENTIFIED VIA mysql_native_password USING 'invalid' OR unix_socket;
  ERROR 1372 (HY000): Password hash should be a 41-digit hexadecimal number

As such, deep the implementation of mysql_native_password we make "invalid" valid (pun intended)
such that the above create user will succeed. We do this by storing
"*THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE" (credit: Oracle MySQL), that is of an INCORRECT
length for a scramble.

In native_password_authenticate we check the length of this cached value
and immediately fail if it is anything other than the scramble length.

native_password_get_salt is only called in the context of set_user_salt, so all setting of native
passwords to hashed content of 'invalid', quite literally create an invalid password.

So other forms of "invalid" are valid SQL in creating invalid passwords:

   MariaDB [(none)]> set password = 'invalid';
   Query OK, 0 rows affected (0.001 sec)

   MariaDB [(none)]> alter user dan@localhost IDENTIFIED BY PASSWORD 'invalid';
   Query OK, 0 rows affected (0.000 sec)

closes #1628

Reviewer: serg@mariadb.com

Thanks to Varun Gupta for suggesting this. This seems to
make main.innodb_ext_key,off more stable.

Invoking memcpy() on a NULL pointer is undefined behaviour
(even if the length is 0) and gives the compiler permission to
assume that the pointer is nonnull. Recent versions of GCC
(starting with version 8) are more aggressively optimizing away
checks for NULL pointers. This undefined behaviour would cause
a SIGSEGV in the test main.func_encrypt on an optimized debug build
on GCC 10.2.0.

This regression was introduced in
commit afc9d00c.
This is a partial backport of
commit 199863d7 from 10.4.

 MDEV-24033: SIGSEGV in __memcmp_avx2_movbe from queue_insert | SIGSEGV in __memcmp_avx2_movbe from native_compare

The issue here was the system variable max_sort_length was being applied
to decimals and it was truncating the value for decimals to the number
of bytes set by max_sort_length.
This was leading to a buffer overflow as the values were written
to the buffer without truncation and then we moved the offset to
the number of bytes(set by max_sort_length), that are needed for comparison.

The fix is to not apply max_sort_length for fixed size types like INT,
DECIMALS and only apply max_sort_length for CHAR, VARCHARS, TEXT and
BLOBS.

cmake has caught up and since version 3.18 it started supporting
CPACK_RPM_POST_TRANS_SCRIPT_FILE, something we've supported for
two years and cmake 2.8.11. Both implementation add %posttrans tag
and rpmbuild gets confused.

Disable our implementation for cmake 3.18+

Also, revert the work-around for the test that was attempted in
commit 85613a32.

This issue was caught by MemorySanitizer as well as on the
Microsoft Windows debug builds, thanks to /MD being used
starting with 10.4.

The code fix will also be applied to 10.2 because the regression
was introduced in commit afc9d00c.

Test itself is not deterministic.

Disable galera_var_replicate_myisam until fixed on 10.4

Use 9 byte (min length packet)

This bug was already fixed in a previous commit.
Added test case from the MDEV to prove it's fixed.

The crash happens because a double free in the case CREATE TABLE fails
because there is a conflicting tables on disk.

Fixed by ensuring that the double free can't happen.

On my system, OpenSuse, I got a compilation error that some arguments
to getgrouplist() where not initialized

For some reason, in the test main,innodb_ext_key,off
we frequently get unexpected EXPLAIN output, in particular
on Microsoft Windows debug builders. Let us comment out that
EXPLAIN statement for now.

The problem was that opt_sum_query() was, as part of MIN/MAX optimization,
doing read operations on constant tables that where already closed

Fixed by ensuring we don't try to read from tables that are closed.