Every operation that is going to write redo log is supposed to
invoke log_free_check() before acquiring any latches. If there
is a risk of log buffer overrun, a log checkpoint would be
triggered by that call.

ibuf_merge_space(), ibuf_merge_in_background(),
ibuf_delete_for_discarded_space(): Invoke log_free_check()
when the current thread is not holding any page latches.

Unfortunately, in lower-level code called from ibuf_insert()
or ibuf_merge_or_delete_for_page(), some page latches may be
held and a call to log_free_check() could hang.

ibuf_set_bitmap_for_bulk_load(): Use the caller's mini-transaction.
The caller should have invoked log_free_check() while not holding
any page latches.

Something appears to be broken in the DBUG subsystem.
Let us remove frequent calls to it from the InnoDB internal SQL interpreter
that is used in the purge of transaction history.

The DBUG_PRINT in que_eval_sql() can remain for now, because those
operations are much less frequent.

InnoDB crash recovery can run out of memory before
commit 50324ce6 in
MariaDB Server 10.5.

Let us disable some frequently failing recovery tests
in earlier versions.

Not creating explicit record locks will speed up the test.

Also, disable the use of InnoDB persistent statistics in the test of
MDEV-27270 to avoid intermittent failures in 10.6 or later
(after commit 9608773f)
due to the nondeterministic scheduling of STATS_AUTO_PERSISTENT.

The file plugin_exports became unused in
commit fec844ac

- mariabackup fails to assign srv_undo_space_id_start when the
dedicated undo tablespaces are disabled

When trying to output stacktrace, and addr2line is not installed, the
child process forked by start_addr2line_fork() will fail to do exec(),
and finish with exit(1).

There is a problem with exit() though - it runs exit handlers,
and for the forked copy of crashing process, it is a bad idea.

In 10.5+ code for example, exit handlers include
tpool::task_group static destructors, and it will hang infinitely
waiting for completion of the outstanding tasks.

The fix is to use _exit() instead, which skips the execution of exit
handlers

Make sure that EXPLAIN object allocated on runtime arena.

/usr/ports/pobj/mariadb-10.9.3/mariadb-10.9.3/mysys/my_lock.c:183:7: warning: incompatible function pointer types assigning to 'sig_return' (aka 'void (*)(void)') from 'void (*)(int)' [-Wincompatible-function-pointer-types]
      ALARM_INIT;
      ^~~~~~~~~~
/usr/ports/pobj/mariadb-10.9.3/mariadb-10.9.3/include/my_alarm.h:43:16: note: expanded from macro 'ALARM_INIT'
                        alarm_signal=signal(SIGALRM,my_set_alarm_variable);
                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/ports/pobj/mariadb-10.9.3/mariadb-10.9.3/mysys/my_lock.c:189:7: warning: incompatible function pointer types passing 'sig_return' (aka 'void (*)(void)') to parameter of type 'void (*)(int)' [-Wincompatible-function-pointer-types]
      ALARM_END;
      ^~~~~~~~~
/usr/ports/pobj/mariadb-10.9.3/mariadb-10.9.3/include/my_alarm.h:44:41: note: expanded from macro 'ALARM_END'
                                              ^~~~~~~~~~~~
/usr/include/sys/signal.h:199:27: note: passing argument to parameter here
void    (*signal(int, void (*)(int)))(int);
                             ^
2 warnings generated.

The prototype is the same for all of the *BSD's.

void
(*signal(int sigcatch, void (*func)(int sigraised)))(int);

Per the code my_set_max_open_files 3 lines earlier, we attempt
to set the nofile (number of open files), rlimit to max_open_files.

We should use this in the warning because wanted_files may not
be the number.

Fix a couple of build warnings that fire with CONNECT engine.

More checks for bad geometry data added.

return an error on invalid gis data

remove useless if()

with C/C.
The patch introduces mariadb_capi_rename.h which is included into
mysql.h. The hew header contains macro definitions for the names being
renamed. In versions 10.6+(i.e. where sql service exists) the renaming
condition in the mariadb_capi_rename.h should be added with
&& !defined(MYSQL_DYNAMIC_PLUGIN)
and look like
The patch also contains removal of mysql.h from the api check.

Disabling false_duper-6543 test for embedded.

ha_federated.so uses C API. C API functions are being renamed in the server,
but not renamed in embedded, since embedded server library should have proper
C API, as expected by programs using it.
Thus the same ha_federated.so cannot work both for server and embedded
server library.

As all federated tests are already disabled for embedded,
federated isn't supposed to work for embedded anyway, and thus the test
is being disabled.

Abort startup, if SSL setup fails.
Also, for the server always check that certificate matches private key
(even if ssl_cert is not set, OpenSSL will try to use default one)

Read the version of the view share when we read definition to prevent
simultaniouse access to a view table SHARE (and so its MEM_ROOT)
from different threads.

MDEV-16549 Server crashes in Item_field::fix_fields on query with view and subquery, Assertion `context' failed, Assertion `field' failed

Add one-table-resolve context for items created with an aim of switching
to temporary table because then it can be cloned in push-down-condition.

The problem was fixed earlier. Adding an MTR test only.

GRANT ROLE can update db-level privileges -> must invalidate acl_cache

* to "clear hostname cache" one needs to use hostname_cache->clear()
* no need to clear acl_cache for SET DEFAULT ROLE

storage/connect/libdoc.cpp:603:17: error: 'void xmlXPathInit()' is deprecated [-Werror=deprecated-declarations]

on Linux this pthread_attr_setstacksize() fails with EINVAL
"The stack size is less than PTHREAD_STACK_MIN (16384) bytes".

But on FreeBSD it succeeds and causes a crash later, as 8196 is too little.

Let's keep the stack at its default size in the timer thread.

(and for 64-bit big endian)

OpenSSL handles memory management using **OPENSSL_xxx** API[^1]. For
allocation, there is `OPENSSL_malloc`. To free it, `OPENSSL_free` should
be called.

We've been lucky that OPENSSL (and wolfSSL)'s implementation allowed the
usage of `free` for memory cleanup. However, other OpenSSL forks, such
as AWS-LC[^2], is not this forgiving. It will cause a server crash.

Test case `openssl_1` provides good coverage for this issue. If a user
is created using:
`grant select on test.* to user1@localhost require SUBJECT "...";`
user1 will crash the instance during connection under AWS-LC.

There have been numerous OpenSSL forks[^3]. Due to FIPS[^4] and other
related regulatory requirements, MariaDB will be built using them. This
fix will increase MariaDB's adaptability by using more compliant and
generally accepted API.

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.

[^1]: https://www.openssl.org/docs/man1.1.1/man3/OPENSSL_malloc.html
[^2]: https://github.com/awslabs/aws-lc
[^3]: https://en.wikipedia.org/wiki/OpenSSL#Forks
[^4]: https://en.wikipedia.org/wiki/FIPS_140-2

st_select_lex::init_query is called in the exectuion of EXECUTE
IMMEDIATE 'alter table ...'. so reset the initialization at the
same point we set join= 0.

and also MDEV-25564, MDEV-18157.

Attempt to produce EXPLAIN output caused a crash in
Explain_node::print_explain_for_children. The cause of this was that an
Explain_node (actually a derived) had a link to child select#N, but
there was no query plan present for select#N.

The query plan wasn't present because the subquery was eliminated.
- Either it was a degenerate subquery like "(SELECT 1)" in MDEV-25564.
- Or it was a subquery in a UNION subquery's ORDER BY clause:
   col IN (SELECT ... UNION
           SELECT ... ORDER BY (SELECT FROM t1))

In such cases, legacy code structure in subquery/union processing code(*)
makes it hard to detect that the subquery was eliminated, so we end up
with EXPLAIN data structures (Explain_node::children) having dangling
links to child subqueries.
Do make the checks and don't follow the dangling links.

(In ideal world, we should not have these dangling links. But fixing
the code (*) would have high risk for the stable versions).

Reviewer: andrew@mariadb.org

InnoDB fails to fetch FTS_DOC_ID if the select query uses secondary
index. So always do extra lookup on clustered index in case of fts
query