Problem was that wsrep thread argument was deleted on wrong
place. Furthermore, scan method incorrectly used unsafe c_ptr().
Finally, fixed wsrep thread initialization to correctly set
up thread_id and pass correct argument to functions and
fix signess problem causing compiler errors.

The execution of mtr in the Windows environment fails due to
the fact that the new code from MDEV-18565 does not take into
account the need to add the ".exe" extension to the names of
executable files when searching for pre-requisites that are
needed to run SST scripts (especially when using mariabackup)
and when searching paths to some other Galera utilities.
This patch fixes this flaw.

Also adding paths to the PATH environment variable is now
done with the correct delimiter character.

Some users and some scripts (for example, mysqld_multi.sh) use special
option groups with names like [mysqld1], [mysqld2], ..., [mysqldN].

But SST scripts can't currently fully support these option groups.
The only option group-related value it gets from the server is
--defaults-group-suffix, if that option was set for mysqld when
the server was started.

However, the SST scripts does not get told by the server to read
these option groups, so this means that the SST script will fail
to read options like innodb-data-home-dir when it is in a option
group like [mysqld1]...[mysqldN].

Moreover, SST scripts ignore many parameters that can be passed
to them explicitly and cannot transfer them further, for example,
to the input of mariabackup utility. Ideally, we want to transfer
all the parameters of the original mysqld call to utilities such
as mariabackup, however the SST script does not receive these
parameters from the server and therefore cannot transfer them to
mariabackup.

To correct these shortcomings, we need to transfer to the scripts
all of the parameters of the original mysqld call, and in the SST
scripts themselves provide for the transfer all of these parameters
to utilities such as mariabackup. To prevent these parameters from
mixing with the script's own parameters, they should be transferred
to SST script after the special option "--mysqld-args", followed by
the string argument with the original parameters, as it received by
the mysqld call at the time of launch (further all these parameters
will be passed to mariabackup, for example).

In addition, the SST scripts themselves must be refined so that
they can read the parameters from the user-selected group, not just
from the global mysqld configuration group. And also so that they
can receive the parameters (which important for their work) as
command-line arguments.

Datafile::find_space_id(): Fix a regression that was introduced
in c0f47a4a for MDEV-12026.
Because the function buf_page_is_corrupted() now determines
the physical page size from the fsp_flags, our buffer size must
agree with the fsp_flags.

buf_page_is_corrupted(): Use the correct accessor
fil_space_t::zip_size() for convering the tablespace flags.
ROW_FORMAT=COMPRESSED files never use innodb_checksum_algorithm=full_crc32.

Stabilize the test:
- replace Rows column in EXPLAIN output for one query
- Use EITS statistics for another query (in that testcase, the
  query must use LooseScan)

Use convert_to_printable function to write only non-empty ranges to the optimizer trace

Optimize the test by dropping the table early and by using only
one undo log thread, so that purge will be doing more useful work
and less busy work of suspending and resuming the worker threads.

The test used to cause shutdown timeout on 10.4 on buildbot, and
for me locally when using --mysqld=--innodb-sync-debug.
With these tweaks, it passes for me with --mysqld=--innodb-sync-debug.

It looks like the merge of MySQL 5.7.9 to MariaDB 10.2.2 conflicted with
earlier changes that were made in MDEV-8588.

row_search_mvcc(): If the page is corrupted, avoid invoking
btr_cur_store_position(). The caller should not try to fetch
the next record after a hard error.

No memory access violated the bounds of fake_extra_buf[],
but GCC does not like the fact that the pointer fake_extra
ends up pointing before the array.
Allocate a dummy element at the start of fake_extra_buf[]
in order to silence the warning.

There were two problems:

(1) If user wanted same time zone information on all nodes in the Galera
cluster all updates were not replicated as time zone information was
stored on MyISAM tables. This is fixed on Galera by altering time zone
tables to InnoDB while they are modified.

(2) If user wanted different time zone information to nodes in the Galera
cluster TRUNCATE TABLE for time zone tables was replicated by Galera
destroying time zone information from other nodes. This is fixed
on Galera by introducing new option for mysql_tzinfo_to_sql_symlink
tool --skip-write-binlog to disable Galera replication while
time zone tables are modified.

Changes to be committed:
        modified:   mysql-test/r/mysql_tzinfo_to_sql_symlink.result
        modified:   mysql-test/suite/wsrep/r/mysql_tzinfo_to_sql_symlink.result
        new file:   mysql-test/suite/wsrep/r/mysql_tzinfo_to_sql_symlink_skip.result
        new file:   mysql-test/suite/wsrep/t/mysql_tzinfo_to_sql_symlink_skip.test
        modified:   sql/tztime.cc

This is 10.4 version of commit fa740888

This triggered a "may be uninitialized" warning from GCC 9.2.1.
The bogus-looking condition was added in
7e916bb8

We need to use wsrep_sync_wait=15 before selects to make sure
that node has applied all inserts from other node.

Merge branch '10.2' into 10.3

ins_node_create() does not initialize all members of que_common_t, so
zero-init them with mem_heap_zalloc().

Handle out-of-memory correctly.

Init insert_node->common.parent to fulfill the contract of thr usage.

Free insert_node subtree at row_update_vers_insert() exit.

Problem:
=======
DROP TABLE IF EXISTS was killed. The table still exists on
the master but the DDL was still logged.

Analysis:
=========
During the execution of DROP TABLE command "ha_delete_table" call is invoked
to delete the table. If the query is killed at this point, the kill command
is not handled within the code. This results in two issues.
1) The table which is not dropped also gets written into the binary log.
2) The code continues further upon receiving 'KILL QUERY'.

Fix:
===
Upon receiving the KILL command the query should stop its current execution.
Tables which were successfully dropped prior to KILL command should be
included in the binary log.

If there're multiple row versions in InnoDB, reading one row from PK
may have O(N) complexity and reading from secondary keys may have
O(N^2) complexity.

The problem occurs when there are many pending versions of the same
row, meaning that the primary key is the same, but a secondary key is
different.  The slowdown occurs when the secondary index is
traversed. This patch creates a helper class for the function
row_sel_get_clust_rec_for_mysql() which can remember and re-use
cached_clust_rec & cached_old_vers so that rec_get_offsets() does not
need to be called over and over for the clustered record.

Corrections by Kevin Lewis <kevin.lewis@oracle.com>

MDEV-20341 Unstable innodb.innodb_bug14704286

Removed test that tested the ability of interrupting long query which
is not long anymore.

Exclude SELECT and INSERT SELECT from vers_set_hist_part(). We cannot
likewise exclude REPLACE SELECT because it may REPLACE into itself
(and REPLACE generates history).

INSERT also does not generate history, but we have history
modification setting which might be interfered.

Fix error code.

Adjust the test for full_crc32.

Problem:
========
Checksum for the encrypted temporary tablespace is not stored in the page
for full crc32 format.

Solution:
========
Made temporary tablespace in full crc32 format irrespective of encryption
parameter.

buf_tmp_page_encrypt(), buf_tmp_page_decrypt() - Both follows full_crc32
format.

This was broken in 2dbe472e

Fixed the following issues:
- Call info with HA_STATUS_CONST to ensure that (key_info->rec_per_key)
  contains latest data
- Don't access rec_per_key if key_info->algorithm == HA_KEY_ALG_LONG_HASH
  is in this case the rec_per_key points to uninitialized data
- Cleaned up code to avoid some extra 'if' and to make things more readable
- Updated test cases that used 'old' rec_per_key values

Enable the rocksdb test suite. It now passes the valgrind tests.