The test was passing some uninitialized data to libmariadb.
Mostly, the MemorySanitizer wrapper of send() detected that
some bytes were uninitialized.

The test_mdev19838() is for now disabled under MemorySanitizer,
to be fixed in MDEV-26761.

Fixes: 5c5ea59b

MDEV-22708 Assertion `!mysql_bin_log.is_open() || thd.is_current_stmt_binlog_format_row()' failed in Delayed_insert::handle_inserts and in Diagnostics_area::set_eof_status

Variable wsrep_forced_binlog_format has higher priority than
binlog_format. In situation where STATEMENT is used and DELAYED INSERT
is executing we should fall back to non-delay INSERT.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Using `innodb_thread_concurrency` will call `wsrep_thd_is_aborting` to
check WSREP thread state. This call should be protected by taking
`LOCK_thd_data` before entering function.
Applier and TOI threads should no be affected with usage of
`innodb_thread_concurrency` variable so returning before any checks.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

If a table has no unique indexes, write set key information will be collected on all columns in the table.
The write set key information has space only for max 3500 bytes for individual column, and if a varchar colummn of such non-primary key table is longer than
 this limit, currently a crash follows.
The fix in this commit, is to truncate key values extracted from such long varhar columns to max 3500 bytes.
This may potentially lead to false positive certification failures for transactions, which operate on separate cluster nodes, and update/insert/delete table rows, which differ only in the part of such long columns after 3500 bytes border.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

In commit 45ed9dd9 (MDEV-23855)
when removing fil_system.LRU we failed to rate-limit the output
for reporting violations of innodb_open_files or open_files_limit.

If the server is run with a small limit of open files that is
well below the number of .ibd files that are being accessed by
the workload, and if at the same time innodb_log_file_size is
very small so that log checkpoints will occur frequently,
the process of enforcing the open files limit may be run very often.

fil_space_t::try_to_close(): Display at most one message per call,
and only if at least 5 seconds have elapsed since the last time a
message was output.

fil_node_open_file(): Only output a summary message if
fil_space_t::try_to_close() displayed a message during this run.
(Note: multiple threads may execute fil_node_open_file() on
different files at the same time.)

fil_space_t::get(): Do not dereference a null pointer if n & STOPPING.
This was caught by the test case below.

Unfortunately, it is not possible to create a fully deterministic
test case (expecting exactly 1 message to be emitted). The following with
--innodb-open-files=10 --innodb-log-file-size=4m
would occasionally fail to find the message in the log:

--source include/have_innodb.inc
--source include/have_partition.inc
--source include/have_sequence.inc

call mtr.add_suppression("InnoDB: innodb_open_files=10 is exceeded");

CREATE TABLE t1 (pk INT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB
PARTITION BY key (pk) PARTITIONS 100;

INSERT INTO t1 SELECT * FROM seq_1_to_100;
--disable_query_log
let $n=400;
while ($n)
{
BEGIN; DELETE FROM t1; ROLLBACK;
dec $n;
}
--enable_query_log

let SEARCH_FILE= $MYSQLTEST_VARDIR/log/mysqld.1.err;
let SEARCH_PATTERN= \[Note\] InnoDB: Cannot close file;
-- source include/search_pattern_in_file.inc

DROP TABLE t1;

FIXME: Part of the MDEV-20699 test is disabled due to
nonderterministic result.

Normally we disable caching of routines in "SHOW CREATE".
Introduce an exception, if debug_dbug="+d,cache_sp_in_show_create".
lock_sync.test needs a way to populate the cache without side effects,
or else it runs into debug_sync timeouts.

So, this possibility to cache will be remain only for very special tests.

Occasionally, after restart, additional transactions will have been
executed, possibly related to innodb_stats_auto_recalc.

We should only care that the transaction ID sequence does
not go backwards.

Apparently, slow shutdown is not necessary anymore after MDEV-15912 fix

Let us mask the actual values of the defragmentation-related fields,
because they may vary. Also, remove the dependency on purge,
and instead delete records by a ROLLBACK of INSERT.

The reason for this behavior is that SP get cached, per connection.
The stored_program_cache is size of this cache, which amounts to 256
routines by default. A compiled stored procedure can easily be several
megabytes in size. Thus calling SHOW CREATE PROCEDURE for all stored
procedures, like mysqldump does, can require significant amount of memory.

Fixed by bypassing the cache for "SHOW CREATE". This should normally be
fine also perfomance-wise, as cache is meant to be used for repeated
execution, not repeated SHOW CREATEs.

Added a test to verify that CREATE PROCEDURE + SHOW CREATE PROCEURE do not
cache, i.e amount of allocated memory does not change.

Note, there is a change in existing behavior in an edge case :
If "SHOW CREATE PROCEDURE p1" called from p1, after p1 was altered, now
this will now return altered code. Previour behavior - relied on caching
and would return old code. The previous behavior might was not necessarily
correct.

MDEV-21613 : galera_sr.GCF-1018B MTR failed: Failed to open table mysql.wsrep_streaming_log for writing

Query can be bf aborted already earlier and then we should not
even try to open table.

Add wait_condition to wait until all nodes are in cluster

Use in_sum_func (and so nest_level) only in LEX to which SELECT lex belong to

Reduce usage of current_select (because it does not always point on the correct
 SELECT_LEX, for example with prepare.

Change context for all classes inherited from Item_ident (was only for Item_field) in case of pushing down it to HAVING.

Now name resolution context have to have SELECT_LEX reference if the context is present.

Fixed feedback plugin stack usage.

Revert 88a4be75 and
9d97f92f, which had been
prematurely pushed by accident.

last commit  8221708e removed too much,
mtr is failing

Create minidump when server fails to shutdown. If process is being
debugged, cause a debug break.

Moves some code which is part of safe_kill into mysys, as both safe_kill,
and mysqltest produce minidumps on different timeouts.

Small cleanup in wait_until_dead() - replace inefficient loop with a single
wait.

Fixed flaws with overly strict or, conversely,
overly soft verification of certificates in some
scenarios:

1. Removed the check that the 'commonname' (CN) in the
   certificate matches the 'localhost' value on the side
   of the joiner node, which was performed earlier, even
   if the address was received by the script only as an
   argument (out of the exchange via the Galera protocol) -
   since for the joining node this argument always contains
   its own local address, not the address of the remote host,
   so it is always treated as 'localhost', which is not
   necessarily true (outside of mtr testing);
2. Removed checking the domain name or IP-address of the
   peer node in the encrypt=2 mode;
3. Fixed checking of compliance of certificates when
   rsync SST is used;
4. Added the ability to specify CA not only as a file,
   but also as a path to the directory where the certificates
   are stored. To do this, the user just needs to specify the
   path to this directory as the value ssl-ca or tca parameter,
   ending with the '/' character.