This commit contains a large set of further bug fixes and
improvements to SST scripts for Galera, continuing the work
that was started in MDEV-24962 to make SST scripts work smoothly
in different network configurations (especially using ipv6) and
with different environment settings:

 1) The ipv6 addresses were incorrectly handled in the SST script
    for rsync (incorrect address substitution for establishing a
    connection, incorrect address substitution for bind, and so on);
 2) Checking the locality of the ip-address in SST scripts did not
    support ipv6 addresses (such as "[::1]"), which were falsely
    identified as non-local ip, which further did not allow running
    two SSTs on different local addresses on the same machine.
    On the other hand, this bug masked some other errors (related
    to handling ipv6 addresses);
 3) The code for checking the locality of the ip address was different
    in the SST scripts for rsync and for mysqldump, with individual
    flaws. This code is now made common and moved to wsrep_sst_common;
 4) Waiting for the start of the transport channel (socat, nc, rsync,
    stunnel) in the wait_for_listen() and check_pid_and_port() functions
    did not process ipv6 addresses correctly in all cases (not for all
    branches);
 5) Waiting for the start of the transport channel (socat, nc, rsync,
    stunnel) in the wait_for_listen() and check_pid_and_port() functions
    for some code branches could give a false positive result due to
    the textual match of prefixes in the port number and/or PID of
    the process;
 6) Waiting for the start of the transport channel (socat, nc, rsync,
    stunnel) was supported through different utilities in SST scripts
    for mariabackup and for rsync, and with various minor flaws in
    the code. Now the code is still different in these scripts, but
    it supports a common set of utilities (lsof, ss, sockstat) and
    is synchronized across patterns that used to check the output
    of  these utilities;
 7) In SST via mariabackup, the signal about readiness to receive data
    is sometimes sent too early - immediately after listen(), and not
    after accept() (which are called by socat or netcat utility).
 8) Checking availability of the some options of some utilities was
    done using the grep pattern, which easily gives false positives;
 9) Common name (CN) for local addresses, if not explicitly specified,
    is now always replaced to "localhost" to avoid the need to generate
    many separate certificates for local addresses of one machine and
    not to depend on which the local address is currently used in test
    (ipv4 or ipv6, etc.);
10) In tests galera_sst_mariabackup_encrypt_with_key_server and
    galera_sst_rsync_encrypt_with_key_server the correct certificate
    is selected to avoid commonname (CN) mismatch problems;
11) Further refactoring to protect against spaces in file names.
12) Further general refactoring to eliminate bash-specific constructs
    or to improve code readability;
13) The code for setting options for the nc (netcat) utility was
    different in different scripts for SST - now it is made identical.
14) Fixed long-time broken encryption via xbcrypt in combination with
    mariabackup and added support for key-based encryption via openssl
    utility, which is now enabled by default for encrypt=1 mode (this
    default mode can be changed using a new configuration file option
    "encypt-format=openssl|xbcrypt", which can be placed in the [mysqld],
    [sst] or in the [xtrabackup] section) - this change will allow us
    to use and to test the encypt=1 encryption without installing
    non-standard third-party utilities.

For the plugin thread during the server start the wsrep_on should be 0.

The problem was that in a timeout event,
thd->lex->restore_backup_query_tables_list() was called when it should
not have been.

Patch tested with the script in MDEV-25651 (not suitable for mtr)

The bug is that we don't have a a lock on the trigger name, so it is
possible for two threads to try to create the same trigger at the same
time and both thinks that they have succeed.
Same thing can happen with drop trigger or a combinations of create and
drop trigger.

Fixed by adding a mdl lock for the trigger name for the duration of the
create/drop.

Patch tested by Elena

This is incosistent with other single config generators, where
the default type has always been RelWithDebInfo.

Fixed by moving setting of CMAKE_BUILD_TYPE right before PROJECT.

unless explicitly overruled with -DWITH_JEMALLOC=no

XA transaction only allows to access data in specific states,
in ACTIVE, but not in IDLE or PREPARE.

But even then one should be able to run SHOW STATUS.

if mysqld is restarted during a test, the debugger script
should be reused or overwritten, but not appended to the existing file

mysqltest has no --gdb option

This reverts commit 72fa9dab

but doesn't recover deleted jars - they still exist in
mysql-test/connect/std_data, no need to have them twice.

Also it removes a redundant copy on JavaWrappers.jar

Remove operations on fil_system.n_open from mariabackup, as they are not
protected by the mutex, and serve no higher purpose anyway.

and configuration.

1. Pass joiner's authentication information to donor together with address
   in State Transfer Request. This allows joiner to authenticate donor on
   connection. Previously joiner would accept data from anywhere.

2. Deprecate custom SSL configuration variables tca, tcert and tkey in favor
   of more familiar ssl-ca, ssl-cert and ssl-key. For backward compatibility
   tca, tcert and tkey are still supported.

3. Allow falling back to server-wide SSL configuration in [mysqld] if no SSL
   configuration is found in [sst] section of the config file.

4. Introduce ssl-mode variable in [sst] section that takes standard values
   and has following effects:
    - old-style SSL configuration present in [sst]: no effect
      otherwise:
    - ssl-mode=DISABLED or absent: retains old, backward compatible behavior
      and ignores any other SSL configuration
    - ssl-mode=VERIFY*: verify joiner's certificate and CN on donor,
                        verify donor's secret on joiner
                        (passed to donor via State Transfer Request)
                        BACKWARD INCOMPATIBLE BEHAVIOR
    - anything else enables new SSL configuration convetions but does not
      require verification

    ssl-mode should be set to VERIFY only in a fully upgraded cluster.

    Examples:

    [mysqld]
    ssl-cert=/path/to/cert
    ssl-key=/path/to/key
    ssl-ca=/path/to/ca

    [sst]

     -- server-wide SSL configuration is ignored, SST does not use SSL

    [mysqld]
    ssl-cert=/path/to/cert
    ssl-key=/path/to/key
    ssl-ca=/path/to/ca

    [sst]
    ssl-mode=REQUIRED

     -- use server-wide SSL configuration for SST but don't attempt to
        verify the peer identity

    [sst]
    ssl-cert=/path/to/cert
    ssl-key=/path/to/key
    ssl-ca=/path/to/ca
    ssl-mode=VERIFY_CA

     -- use SST-specific SSL configuration for SST and require verification
        on both sides
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

1. Fix eval command line to correctly pass stunnel option to rsync on donor.
2. Deprecate `tkey`, `tcert` and `tca` options in [sst] section in favor of
   conventional `ssl-key`, `ssl-cert` and `ssl-ca`, but keep their precedence
   for backward compatibility.
3. Default to require SSL encryption if at least SSL key and cert files are
   specified in configuration, either in [sst] or [mysqld] sections.
4. Enable `verify*` option for stunnel on donor only if
   a. CA file is specified somewhere in the configuration
   b. it is explicitly requested in [sst] section by either specifying
   ssl-mode or CA file there. In this case if ssl-mode is not explicitly
   given, it defaults to VERIFY_CA.

   ssl-mode maps to stunnel options as follows:
   VERIFY_CA       -> verifyChain = yes
   VERIFY_IDENTITY -> verifyPeer = yes

   Example to require donor to verify joiner identity:
```
[mysqld]
ssl-cert=/path/to/cert
ssl-key=/path/to/key
ssl-ca=/path/to/ca

[sst]
ssl-mode=VERIFY_IDENTITY
```
5. If SSL verification is requested, joiner verifies donor by checking the
   secret passed to donor via SST request.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

058d93d4 introduced a switch in autobake
script to append dh-systemd package when it is necessary. However, the
change was not complete as it didn't actually remove the dh-systemd
dependency in debian/control.

after b9d64989 the test for MDEV-16962 is not suitable anymore
(and probably the bug is not reproducible).

1) Checked presence of mysys_var.
2) Removed unneeded thd_clear_errors,
  its content added to THD::change_user.

The test innodb.doublewrite could occasionally fail with 64KiB page size
because the page 0 would no longer be in the doublewrite buffer.
Let us stop purge before the server is killed, and ensure that
the entire buffer pool will be flushed before we initiate an extra
write of page 0.

Fixed NULL pointer reference to db.str

Keep the readline installation step in Salsa-CI stages that install
MariaDB.org packages in Debian Sid (or releases after is, such as
Debian 11 "Bullseye" or Ubuntu 21.04 "Hirsute") as those old packages
still depend on readline for the MariaDB Server itself.

When you only need view structure, don't call handle_derived with
DT_CREATE and rely on its internal hackish check to skip DT_CREATE.
Because handle_derived is called from many different places,
and this internal hackish check is indiscriminative.

Instead, just don't ask handle_derived to do DT_CREATE
if you don't want it to do DT_CREATE.