The hang may be caused by a 1pc branch that was fixed by MDEV-26031 in
10.6 and up. That commit did not look relevant in 10.5 and below
so  was not pushed to the low branches.

To possibly tackle the reported issue
the MDEV-26031 is backported now with a test that
unlike 10.6 does not expose the former bug in 10.5.
It is only needed for checking a refined logics
inside MYSQL_BIN_LOG::write_transaction_to_binlog.
The latter is made to do away with xid-unlogging (which is suspected
to have been at fault) for xid-less transaction.

Close handlers in THD::drop_temporary_table.

Step 1 in handling InnoDB AIO assertions better is to get
more detail of the cases of error.

This doesn't resolve MDEV-27593, but increases the level
of information in the assertion.

Fix the side effect of MDEV-4750 (reenabling innodb_stats_persistent),
so that sporadic MDL acquisition for this table does not interfere with
SELECT from information_schema.metadata_lock_info

mysql_json: GAMMA -> STABLE

Depending on OpenSSL version, and at least in 3.0.3, the client-side socket
timeout is reported as generic error (SSL_ERROR_SYSCALL), losing further
details (both errno and GetLastError() return 0). This results in client
reporting "Unknown OpenSSL error" 2026, instead of another generic
"Lost connection to server during query" 2013

Adjusted test case.

Part of MDEV-29000

OpenSSL 3.0.0+ does not support EVP_MD_CTX_FLAG_NON_FIPS_ALLOW any longer.
In OpenSSL 1.1.1 the non FIPS allowed flag is context specific, while
in 3.0.0+ it is a different EVP_MD provider.

Fixes #2010

part of MDEV-29000

This reverts commit c9beef43, because
we have OpenSSL 3.0 support here.

part of MDEV-29000

Summary of changes

- MD_CTX_SIZE is increased

- EVP_CIPHER_CTX_buf_noconst(ctx) does not work anymore, points
  to nobody knows where. The assumption made previously was that
  (since the function does not seem to be documented)
  was that it points to the last partial source block.
  Add own partial block buffer for NOPAD encryption instead

- SECLEVEL in CipherString in openssl.cnf
  had been downgraded to 0, from 1, to make TLSv1.0 and TLSv1.1 possible
   (according to https://github.com/openssl/openssl/blob/openssl-3.0.0/NEWS.md
   even though the manual for SSL_CTX_get_security_level claims that it
   should not be necessary)

- Workaround Ssl_cipher_list issue, it now returns TLSv1.3 ciphers,
  in addition to what was set in --ssl-cipher

- ctx_buf buffer now must be aligned to 16 bytes with openssl(
  previously with WolfSSL only), ot crashes will happen

- updated aes-t , to be better debuggable
  using function, rather than a huge multiline macro
  added test that does "nopad" encryption piece-wise, to test
  replacement of EVP_CIPHER_CTX_buf_noconst

part of MDEV-29000

ha_innobase::check_if_supported_inplace_alter(): Refuse to change the
collation of a column that would become or remain indexed as part of
the ALTER TABLE operation.

In MariaDB Server 10.6, we will allow this type of operation;
that fix depends on MDEV-15250.

Starting with 10.5, InnoDB crash recovery tests seem to time out
more easily under Valgrind, which emulates multiple threads by
interleaving them in a single operating system thread.

These tests will still be covered by
AddressSanitizer and MemorySanitizer.

- InnoDB mistakenly identifies the non-unique FTS_DOC_ID index as
FTS_DOC_ID_INDEX while loading the table. dict_load_indexes()
should check whether the index is unique before assigning
fts_doc_id_index

Before version 10, GCC would think that a right shift of an
unsigned char returns int. Let us explicitly cast that back,
to silence a bogus -Wconversion warning.

Also, refactor trx_i_s_common_fill_table() to remove dead code.

Warnings about yynerrs in Bison-generated yyparse() will remain for now.

K&R style function definitions are deprecated in all versions of C
and not supported in C2x.

MDEV-28919 Assertion `(((core_null) + 7) >> 3) == oindex.n_core_null_bytes || !not_redundant()' failed

- In case of discarded tablespace, InnoDB can't read the root page to
assign the n_core_null_bytes. Consecutive instant DDL fails because
of non-matching n_core_null_bytes.

fil_space_t::acquire_low(): Introduce a parameter that specifies
which flags should be avoided. At all times, referenced() must not
be incremented if the STOPPING flag is set. When fil_system.mutex
is not being held by the current thread, the reference must not be
incremented if the CLOSING flag is set (unless NEEDS_FSYNC is set,
in fil_space_t::flush()).

fil_space_t::acquire(): Invoke acquire_low(STOPPING | CLOSING).
In this way, the reference count cannot be incremented after
fil_space_t::try_to_close() invoked fil_space_t::set_closing().

If the CLOSING flag was set, we must retry acquire_low() after
acquiring fil_system.mutex.

fil_space_t::prepare_acquired(): Replaces prepare(true).

fil_space_t::acquire_and_prepare(): Replaces prepare().
This basically retries fil_space_t::acquire() after
acquiring fil_system.mutex.

- Redundant InnoDB table fails to set the flags2 while loading
the table. It leads to "Upgrade index name failure" during alter
operation. InnoDB should set the flags2 to FTS_AUX_HEX_NAME when
fts is being loaded

Log MDL state transitions. Trace-friendly message
format. DBUG_LOCK_FILE replaced by thread-local storage.

Logged states legend:
  Seized   lock was acquired without waiting
  Waiting  lock is waiting
  Acquired lock was acquired after waiting
  Released lock was released
  Deadlock lock was aborted due to deadlock
  Timeout  lock was aborted due to timeout >0
  Nowait   lock was aborted due to zero timeout
  Killed   lock was aborted due to kill message
  OOM	   can not acquire because out of memory

Usage:
  mtr --mysqld=--debug=d,mdl,query:i:o,/tmp/mdl.log

Cleanup from garbage messages:
  sed -i -re \
  '/(mysql|performance_schema|sys|mtr)\// d; /MDL_BACKUP_/ d' \
  /tmp/mdl.log

A cleanup for MDEV-25243 ASAN heap-use-after-free in Item_func_sp::execute_impl upon concurrent view DDL and I_S query with view and function

The test was reported to fail sporadicaly with this diff:

--- mysql-test/main/information_schema_tables.result
+++ mysql-test/main/information_schema_tables.reject
@@ -21,6 +21,8 @@
 disconnect con1;
 connection default;
 DROP VIEW IF EXISTS vv;
+Warnings:
+Note	4092	Unknown VIEW: 'test.vv'

in the "The originally reported non-deterministic test" part.
Disabling warnings around the DROP VIEW statement.

The Spider mixes the comma join with other join types, and thus
ERROR 1054 occurs. This is well-known issue caused by the higher
precedence of JOIN over the comma (,).

We can fix the problem simply by using JOINs instead of commas.

MDEV-21310 AUTO_INCREMENT column throws range error on INSERT in partitioned table | Assertion `part_share->auto_inc_initialized || !can_use_for_auto_inc_init()' failed.

The bug is caused by a similar mechanism as MDEV-21027.

The function, check_insert_or_replace_autoincrement, failed to open
all the partitions on INSERT SELECT statements and it results in the
assertion error.

The heap-use-after-free is caused by the following mechanism:

  * In the execution of FLUSH TABLE WITH READ LOCK, the function
    spider_free_trx_conn() is called and the connections held by
    SPIDER_TRX::trx_conn_hash are freed.

  * Then, an instance of ha_spider maintains the freed connections
    because they are also referenced from ha_spider::conns.
    The ha_spider instance is kept in a lock structure until the
    corresponding table is unlocked.

  * Spider accesses ha_spider::conns on the implicit UNLOCK TABLE
    issued by BEGIN.

In the first place, when the connections have been freed, it means
that there are really no remote table locked by Spider.
Thus, there is no need for Spider to access ha_spider::cons on the
implicit UNLOCK TABLE.

We can fix the bug by removing the above mentioned access to
ha_spider::conns. We also modified spider_free_trx_conn() so that it
frees the connections only when no table is locked to reduce the
chance of another heap-use-after-free on ha_spider::conns.

prepare_inplace_alter_table_dict(): If the table will not be rebuilt,
preserve all of the original ROW_FORMAT, including the compressed
page size flags related to ROW_FORMAT=COMPRESSED.

hex_to_ascii(): Add #if around the definition to avoid
clang -Wunused-function. Avoid GCC 5 -Wconversion with a cast.

buf_page_print(): Dump the buffer page 32 bytes (64 hexadecimal digits)
per line. In this way, the limitation in mtr
("Data too long for column 'line'") will not be triggered.

Also, do not bother decoding the page contents, because everything
is present in the hexadecimal output.

dict_index_find_on_id_low(): Merge to dict_index_get_if_in_cache_low().
The direct call in buf_page_print() was prone to crashing, in case the
table definition was concurrently evicted or dropped from the
data dictionary cache.

Spider supports (or at least allows) INSERT DELAYED but the
documentation does not specify spider as a storage engine that supports
"INSERT DELAYED".
Also, although not mentioned in the documentation, "INSERT DELAYED" is
not intended to be executed inside a transaction, as can be seen from
the list of supported storage engines.
The current implementation allows executing a delayed insert on a
remote transactional table and this breaks the consistency ensured by
the transaction.

We too remove "internal_delayed", one of the Spider table parameters.
Documentation says,

> Whether to transmit existence of delay to remote servers when
> executing an INSERT DELAYED statement on local server.

This table parameter is only used for "INSERT DELAYED".

Reviewed by: Nayuta Yanagisawa

MDEV-22590 SIGSEGV in flush_all_key_blocks when changing key_buffer_size / ASAN: heap-use-after-free in flush_all_key_blocks

Take into account that in preparation of a simple key cache for resizing no disk blocks might be assigned to it.

Reviewer: IgorBabaev <igor@mariadb.com>

Fixed tpool timer implementation on POSIX.
Prior to this patch, under some specific rare circumstances (concurrency
related), timer callback execution might be skipped.

This commit contains workaround for a bug known as 'Red Hat issue 1870279'
(connection reset by peer issue in socat versions 1.7.3.3 to 1.7.4.0) which
further causes crashes during SST using mariabackup (when openssl is used).

Also fixed broken logic of automatic generation of the Diffie-Hellman parameters
for socat version less than 1.7.3 (which defaults to 512-bit values instead of
2048-bit ones).