MDEV-19243 introduced a regression on Windows.

In (supposedly rare) case, where environment variable TZ was set,
@@system_time_zone no longer derives from TZ. Instead, it incorrecty
refers to system default time zone, eventhough UTC time conversion
takes TZ into account.

The fix is to restore TZ-aware handling (timezone name derives from
tzname), if TZ is set.

The statement 'Verify checksum binlog events.' is confusing. Fix word order to make it clear.

The problem is related to performing operations without switching
wsrep off, this commit fixes this and allows disabled tests.

A previous fix in commit efd8af53
failed to cover ALTER TABLE.

PageBulk::isSpaceAvailable(): Check for record heap number overflow.

Reviewer: <wlad@mariadb.com>

Do not allow setting wsrep_on=ON if no provider is set.

           upon CREATE OR REPLACE causing ER_UPDATE_TABLE_USED

Missed set return status to 1.

When f.ex. table is partitioned by HASH(a) and we rename column `a' to
`b' partitioning filter stays unchanged: HASH(a). That's the wrong
behavior.

The patch updates partitioning filter in accordance to the new columns
names. That includes partition/subpartition expression and
partition/subpartition field list.

For "const char *" replace() and after() accepted const as "T *" and
passed forward "void *". This cannot be cast implicitly, so we better
use "const void *" instead of "void *" in the input interface. This
way we avoid problems with using List for any const type.

MDEV-27927 row_sel_try_search_shortcut_for_mysql() does not latch a page, violating read view isolation

btr_search_guess_on_hash() would only acquire an index page latch if it
is invoked with ahi_latch=NULL. If it's invoked from
row_sel_try_search_shortcut_for_mysql() with ahi_latch!=NULL, a page
will not be latched, and row_search_mvcc() will get a pointer to the
record, which can be changed by some other transaction before the record
was stored in result buffer with row_sel_store_mysql_rec() call.

ahi_latch argument of btr_cur_search_to_nth_level_func() and
btr_pcur_open_with_no_init_func() is used only for
row_sel_try_search_shortcut_for_mysql().
btr_cur_search_to_nth_level_func(..., ahi_latch !=0, ...) is invoked
only from btr_pcur_open_with_no_init_func(..., ahi_latch !=0, ...),
which, in turns, is invoked only from
row_sel_try_search_shortcut_for_mysql().

I suppose that separate case with ahi_latch!=0 was intentionally
implemented to protect row_sel_store_mysql_rec() call in
row_search_mvcc() just after row_sel_try_search_shortcut_for_mysql()
call. After the ahi_latch was moved from row_seach_mvcc() to
row_sel_try_search_shortcut_for_mysql(), there is no need in it at all
if btr_search_guess_on_hash() latches a page unconditionally. And if
btr_search_guess_on_hash() latched the page, any access to the record in
row_sel_try_search_shortcut_for_mysql() after btr_pcur_open_with_no_init()
call will be protected with the page latch.

The fix is to remove ahi_latch argument from
btr_pcur_open_with_no_init_func(), btr_cur_search_to_nth_level_func()
and btr_search_guess_on_hash().

There will not be test, as to test it we need to freeze some SELECT
execution in the point between row_sel_try_search_shortcut_for_mysql()
and row_sel_store_mysql_rec() calls in row_search_mvcc(), and to change
the record in some other transaction to let row_sel_store_mysql_rec() to
store changed record in result buffer. Buf we can't do this with the
fix, as the page will be latched in btr_search_guess_on_hash() call.

Let us disable Valgrind on tests that would fail because a
server shutdown or a STOP SLAVE command would take longer,
causing the test harness to forcibly and silently kill the server
due to an exceeded timeout.

Under Valgrind, this test may occasionally fail because the sleep-based
timeouts of less than 1 second could be exceeded.

The test could emit some I/O error when run under Valgrind.

row_purge_get_partial(): Replaces trx_undo_rec_get_partial_row().
Also copy the purge_node_t::ref to the purge_node_t::row.
In this way, the clustered index key fields will always be
available, even if thanks to
commit d384ead0 (MDEV-14799)
they would no longer be repeated in the remaining part of the
undo log record.

This commit adds automation that will reduce the possibility
of user errors when customizing wsrep_notify.sh (in particular
caused by user-specified parameters). Now all leading and trailing
spaces are removed from the user-specified parameters and automatic
port and host address substitution has been added to scripts, as
well as automatic password substitution to the client command line,
only if it is specified in the wsrep_notify.sh and not as empty
strings. Also added support for automatic substitution of the all
SSL-related parameters and improved parsing for ipv6 addresses
(to allow "[...]" notation for ipv6 addresses). Also added a
test to check if the wsrep notify script will works with SSL.

MDEV-29575 Access to innodb_trx, innodb_locks and innodb_lock_waits along with detached XA's can cause SIGSEGV

trx->mysql_thd can be zeroed-out between thd_get_thread_id() and
thd_query_safe() calls in fill_trx_row(). trx_disconnect_prepared() zeroes out
trx->mysql_thd. And this can cause null pointer dereferencing in
fill_trx_row().

fill_trx_row() is invoked from fetch_data_into_cache() under trx_sys.mutex.

Bug fix is in reseting trx_t::mysql_thd in trx_disconnect_prepared() under
trx_sys.mutex lock too.

MTR test case can't be created for the fix, as we need to wait for
trx_t::mysql_thd reseting in fill_trx_row() after trx_t::mysql_thd was
checked for null while trx_sys.mutex is held. But trx_t::mysql_thd must be
reset in trx_disconnect_prepared() under trx_sys.mutex. There will be deadlock.

extended initializers are only allowed since c++11

MDEV-17124: mariadb 10.1.34, views and prepared statements:  ERROR 1615 (HY000): Prepared statement needs to be re-prepared

The problem is that if table definition cache (TDC) is full of real tables
which are in tables cache, view definition can not stay there so will be
removed by its own underlying tables.
In situation above old mechanism of detection matching definition in PS
and current version always require reprepare and so prevent executing
the PS.

One work around is to increase TDC, other - improve version check for
views/triggers (which is done here). Now in suspicious cases we check:
 - timestamp (microseconds) of the view to be sure that version really
   have changed;
 - time (microseconds) of creation of a trigger related to time
   (microseconds) of statement preparation.

- Added missing information about database of corresponding table for various types of commands
- Update some typos

- Reviewed by: <vicentiu@mariadb.org>

KILL QUERY ID 0 was sometimes finding con3 that was still in the process
of disconnecting and had query_id==0 (as it didn't run any queries)

This patch resolves the problem of improper name resolution of table
references to embedded CTEs for some queries. This improper binding could
lead to
  - infinite sequence of calls of recursive functions
  - crashes due to resolution of null pointers
  - wrong result sets returned by queries
  - bogus error messages

If the definition of a CTE contains with clauses then such CTE is called
embedding CTE while CTEs from the with clauses are called embedded CTEs.
If a table reference used in the definition of an embedded CTE cannot be
resolved within the unit that contains this reference it still may be
resolved against a CTE definition from the with clause with one of the
embedding CTEs.
A table reference can be resolved against a CTE definition if it used in
the the scope of this definition and it refers to the name of the CTE.
Table reference t is in the scope of the CTE definition of CTE cte if
- the definition of cte is an element of a with clause declared as
  RECURSIVE and the reference t belongs either to the unit to which
  this with clause is attached or to one of the elements of this clause
- the definition of cte is an element of a with clause without RECURSIVE
  specifier and the reference t belongs either to the unit to which this
  with clause is attached or to one of the elements from this clause that
  are placed before the definition of cte.
If a table reference can be resolved against several CTE definitions then
it is bound to the most embedded.

The code before this patch not always resolved table references used in
embedded CTE according to the above rules.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

Continue with similar changes as done in 19af1890 to replace sprintf(buf, ...)
with snprintf(buf, sizeof(buf), ...), specifically in the "easy" cases where buf
is allocated with a size known at compile time.

All new code of the whole pull request, including one or several files that are
either new files or modified ones, are contributed under the BSD-new license.  I
am contributing on behalf of my employer Amazon Web Services, Inc.

When the partition table is cloned, the handlers for the partitions that were not opened
should anyway be created (but not opened).

Nowdays subquery in a UNION's ORDER BY placed correctly in fake select,
the only problem was incorrect Name_resolution_contect is fixed by this
patch in parsing, so we do not need scanning/reseting of ORDER BY of
a union.

The warning "maybe-uninitialized" raises on spd_sys_table.cc and
ha_spider.cc when the sever is compiled with CMAKE_CXX_FLAGS=-Og.

show error messages from mysqldump/mysqlimport

give every bootstrap server its own tmpdir, by default it's var/tmp,
which is shared in --parallel

There are currently two things causing ASAN hits on CONNECT engine when
the plugin is used as a dynamic module. These are libxml2 and libodbc.

libxml2 has some quirks when not the first and last thing called in the
main thread of an application, some of the global memory isn't cleaned
up correctly. The same is assumed of libodbc but this does not have
explicit API for this.

This is being fixed in two ways.

First we are removing the libxml2 cleanup call. This is because the
current one is messy and whatever it fixed has gone away. But also
because if this is called and libxml2 is used again this can cause
issues. For example if two different plugins to MariaDB both happen to
use libxml2.

The second fix is a hack that exploits `STB_GNU_UNIQUE` so that when
compiled with ASAN the plugin will remain in memory after dlclose().
This allows libodbc to cleanup and has the added advatage that we will
get clean stacks from ASAN for CONNECT when the leak is detected at the
end of execution.

Details of the `STB_GNU_UNIQUE` method can be found here:

https://web.archive.org/web/20100730094324/http://www.redhat.com/archives/posix-c++-wg/2009-August/msg00002.html

When an UPDATE or DELETE was executed with a WHERE condition it would
crash the MariaDB server. This is because the code expects the WHERE
condition to have generated a query string but it hasn't.

Also updates the ODBC test results for current MariaDB version.

row_log_table_apply_update(): Free the pcur.old_rec_buf before returning.
It may be allocated by btr_pcur_store_position() inside
btr_blob_log_check_t::check() and btr_store_big_rec_extern_fields().

This memory leak was introduced in
commit 2e814d47 (MariaDB Server 10.2.2)
via mysql/mysql-server@ce0a1e85e24e48b8171f767b44330da635a6ea0a
(MySQL 5.7.5).

The fix for MDEV-29352 was pushed to 10.6+ but the code causing the
bug is old and the bug is unlikely to be a recent regression in 10.6.
So, we apply the fix also to older versions, 10.3-10.5.

The original commit message:

MDEV-29352 SIGSEGV's in strlen and unknown location on optimized builds at SHUTDOWN

When the UDF creation frails to write the newly created UDF into
the related system table, the UDF is still created in memory.

However, as it is now, the related DLL is unloaded in this case right
in the mysql_create_function. And failure happens when the UDF handle
is freed and tries to unload the respective DLL which is still unloaded.