The asserion failure was caused by this query

  select /*id=1*/ from t1
  where
   col= ( select /*id=2*/ from ... where corr_cond1
          union
          select /*id=4*/ from ... where corr_cond2)

Here,
- select with id=2 was correlated due to corr_cond1.
- select with id=4 was initially correlated due to corr_cond2, but then
  the optimizer optimized away the correlation, making the select with id=4
  uncorrelated.

However, since select with id=2 remained correlated, the execution had to
re-compute the whole UNION. When it tried to execute select with id=4, it
hit an assertion  (join buffer already free'd).

This is because select with id=4 has freed its execution structures after
it has been executed once. The select is uncorrelated, so it did not expect
it would need to be executed for the second time.

Fixed this by adding this logic in
st_select_lex::optimize_unflattened_subqueries():

  If a member of a UNION is correlated, mark all its members as
  correlated, so that they are prepared to be executed multiple times.

don't let Aria create a table that it cannot open

use the correct check. before invoking handler methods we
need to know that the table was opened, not only created.

Do not assume that subquery Item always present.

Removed all dependencies of command line arguments based on positions in
an array (this kind of code should never have been written).
Instead use option names, which are stable.

Reviewer: Sergei Golubchik

Use portable quoting in mtr_add_arg.

- Changed SST scripts to use /usr/bin/env bash instead of
  /bin/bash for better portability.
- Fixed use of mktemp on non-Linux platforms to produce
  temporary file instead of directory.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

(Backport Varun Gupta's patch + edit the commit comment)

Name resolution code produced errors for valid queries with window
functions (but not for queries which used aggregate functions as
window functions).

Name resolution code worked incorrectly, because window function
objects had is_window_func_sum_expr()=false. This was so, because
mark_as_window_func_sum_expr() was only called for aggregate functions
used as window functions.

The fix is to call it for any window function.

Fixed the test to execute only on linux as it depends on unportable sed.

Add error from later versions to avoid chaging HA_ERR_*
accross versions and in already released versions.

revert 68b3fa88

accessing freed memory.
Before XMLCOL::WriteColumn() Tdbp->Clist gets assigned
a nodelist in

      Clist = RowNode->SelectNodes(g, Colname, Clist);

which is RowNode->Doc->Xop->nodesetval.

In XMLCOL::WriteColumn()

        ValNode = ColNode->SelectSingleNode(g, Xname, Vxnp);

calls LIBXMLDOC::GetNodeList() again, which frees the previous
XPath object Xop and replaces it with a new one.

In this case RowNode->Doc == ColNode->Doc, so Clist->Listp
points to a freed memory now.

fix it for Aria too

- Revert wrongly record embedded result files. These were either
  recorded with normal server (not embedded) or an embedded server
  with not default compile option. This can be seen that the committed
  result file had replication variables which should never happen.

- Reverted back change of include/is_embedded.inc. One cannot check for
  $MYSQL_EMBEDDED as this only tells if there exists an embedded
  server, not if the current server we are testing is the embedded
  server. This could easily be verified by doing
  'mtr sys_vars.sysvars_server_embedded'. This would fail with a wrong
  result instead of being marked as skipped as --embedded was not
  used.

This happens when compiled with HAVE_EMBEDDED_PRIVILEGE_CONTROL.
There is a lot of other problems with the above option that should
be fixed at some point

This failed because of MDEV-18918 which removed DEFAULT's

Backport from 10.6

Adds reload and --datadir functionality to mysqld_multi
Increased version to 3.0

Source:
https://github.com/openSUSE/mysql-packaging/blob/master/patches/mysql-patches/mariadb-10.0.15-mysqld_multi-features.patch

Author: Michal Hrusecky <Michal.Hrusecky@opensuse.org>
Reviewer: monty@mariadb.org

This patch fixes the logrotate config file for mariadb.
Read more at https://www.novell.com/support/kb/doc.php?id=7005219

Source:
https://github.com/openSUSE/mysql-packaging/blob/master/patches/mysql-patches/mariadb-10.0.15-logrotate-su.patch

Suggested by serg@mariadb.org

This avoids printing the error
"mysqld: file-key-management-filename  is not set"
which can happen if the file-key-management pluging is statically compiled

Removed the option as it safe to always create the file when we have
created the MariaDB data directories. This fixes this issue not only
for debian but for all MariaDB users.

This patch let's you specify not only user to use but also group that
MariaDB should use.

Original patch:
https://github.com/openSUSE/mysql-packaging/blob/master/patches/mysql-patches/mariadb-10.2.3-group.patch

Author:   Kristyna Streitova
Reviewer: monty@mariadb.org

The assert was caused by an error of XA transaction that had
BINLOG 'base64_string' statement.
The statement failed because of lack of checking whether the encoded
replication event was handled by the slave applier thread.
If it's not the slave applier no error should be generated, but it was
in this case, see a test added.

Fixed along with the idea borrowed the upstream to introduce a check
of which applier executes the replication event and do not
report any error if the applier is a regular server client.

Add test case that reproduces the issue and update wsrep-lib submodule
to include the fix.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

MDEV-26953 Assertion `!str || str != Ptr || !is_alloced()' failed in String::copy upon SELECT with sjis

Item::save_str_in_field() passes &Item::str_value as a parameter
to val_str().

Item_func::make_empty_result() also fills and returns str_value.

As a result, in the reported scenario in
Item_func::val_str_from_val_str_ascii()
both "str" and "res" pointed to Item::str_value,
which made the DBUG_ASSERT inside String::copy()
(preventing copying to itself) crash:

  if ((null_value= str->copy(res->ptr(), res->length(),
                             &my_charset_latin1, collation.collation,
                             &errors)))

Fix:
- Adding a String* parameter to make_empty_result()
- Passing the val_str() parameter to make_empty_string().