In commit 244fdc43 (MDEV-29438)
we made sure that if the preceding record is the page infimum record,
no more than 8 bytes will be read from it. But, if the data payload of
the being-inserted record is less than 8 bytes (this can happen in
secondary indexes), we must not compare all 8 bytes.

This was caught by a failure of the test gcol.innodb_virtual_basic
under MemorySanitizer and some builds with AddressSanitizer.

- This is caused by commit 1bd681c8(MDEV-25506)
InnoDB removes the index from the table object before freeing the
leaf and non-leaf segments.

The resources like uring in MariaDB aren't intended for spawned
processes so we restrict access using the io_uring_ring_dontfork
liburing library call.

This bug was found in MariaDB Server 10.6 thanks to the
OPT_PAGE_CHECKSUM record that was implemented
in commit 4179f93d for catching
this type of recovery failures.

page_cur_insert_rec_low(): If the previous record is the page infimum,
correctly limit the end of the record. We do not want to copy data from
the header of the page supremum. This omission caused the incorrect
recovery of DB_TRX_ID in an instant ALTER TABLE metadata record, because
part of the DB_TRX_ID was incorrectly copied from the n_owned of the
page supremum, which in recovery would be updated after the copying,
but in normal operation would already have been updated at the time the
common prefix was being determined.

log_phys_t::apply(): If a data page is found to be corrupted, do not
flag the log corrupted but instead return a new status APPLIED_CORRUPTED
so that the caller may discard all log for this page. We do not want
the recovery of unrelated pages to fail in recv_recover_page().

No test case is included, because the known test case would only work
in 10.6, and even after this fix, it would trigger another bug in
instant ALTER TABLE crash recovery.

These files are currently not being used nor compiled in MariaDB. The
use of large lists of 'case' statements in these source files are also
not a great way to represent translated strings. This git history can
be referred to when a better translation interface can be implemented
in the future.

Therefore, these files can be removed to cleanup the MariaDB codebase.

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.

- During rollback of DDL, InnoDB should copy the collation
changed column into the index heap

btr_validate_level(): Invoke mtr.commit() after a failure.
This omission was introduced in
commit 0b47c126 (MDEV-13542).

If multiple threads invoke buf_page_get_low() on a ROW_FORMAT=COMPRESSED
page that does not reside in the buffer pool, then one of the threads
will end up acquiring an exclusive page latch (the "if" statement
right before the new wait_for_unzip: label) and other threads will
end up waiting for a shared latch while holding a buffer-fix.
The exclusive latch holder would then wait for the buffer-fixes to
be released while the buffer-fix holders are waiting for the shared latch.

buf_page_get_low(): Prevent the hang that was introduced
in commit 9436c778 (MDEV-27058),
by releasing the buffer-fix, sleeping some time, and retrying the
page lookup.

recv_sys_t::free_corrupted_page(): Identify the corrupted page in
an error or warning message.

buf_page_free(): Just in case, register the page as modified.
This should already have been done in mtr_t::free() as part of
fseg_free_page_low().

mtr_t::memo_push(): Simplify a condition, so that when invoked
with MTR_MEMO_PAGE_X_MODIFY, we will do the right thing.

fseg_free_page_low(): Remove an accidentally added return statement
that prevented mtr_t::free() from being called. This fixes a regression
that was introduced in
commit 0b47c126 (MDEV-13542).

Making changes to wsrep_mysqld.h causes large parts of server code to
be recompiled. The reason is that wsrep_mysqld.h is included by
sql_class.h, even tough very little of wsrep_mysqld.h is needed in
sql_class.h. This commit introduces a new header file, wsrep_on.h,
which is meant to be included from sql_class.h, and contains only
macros and variable declarations used to determine whether wsrep is
enabled.
Also, header wsrep.h should only contain definitions that are also
used outside of sql/. Therefore, move WSREP_TO_ISOLATION* and
WSREP_SYNC_WAIT macros to wsrep_mysqld.h.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Because of a define error the wrong value was being returned.

Regression in MDEV-28243

Fixes: 607f9874679c3e4ef7edcd2c9d80120051af73cc

Thanks to references from Brad Smith, BSDs use getmntinfo as
a system call for mounted filesystems.

Most BSDs return statfs structures, (and we use OSX's statfs64),
but NetBSD uses a statvfs structure.

Simplify Linux getmntent_r to just use getmntent.

AIX uses getmntent.

An attempt at writing Solaris compatibility with
a small bit of HPUX compatibility was made based on man page
entries only. Fixes welcome.

statvfs structures now use f_bsize for consistency with statfs

Test case adjusted as PATH_MAX is OS defined (e.g. 1023 on AIX)

Fixes: 0ee5cf83

also fixes:

MDEV-27818: Disk plugin does not show zpool mounted devices

This is because zpool mounted point don't begin with /.

Due to the proliferation of multiple filesystem types since this
was written, we restrict the entries listed in the disks plugin
to excude:
* read only mount points (no point monitoring, and
  includes squash, snaps, sysfs, procfs, cgroups...)
* mount points that aren't directories (excludes /etc/hostname and
  similar mounts in containers). (getmntent (Linux/AIX) only)
* exclude systems where there is no capacity listed (excludes various
  virtual filesystem types).

Reviewer: Sergei Golubchik

Add ORDER BY to make the test deterministic.

Add FLUSH TABLES to avoid crash recovery warnings about the table
mysql.plugin. This tends to occur on Valgrind, where the server
shutdown could presumably time out, resulting in a forced kill.

dict_table_rename_in_cache(), dict_table_get_highest_foreign_id():
Reserve sufficient space for the fkid[] buffer, and ensure that the
fkid[] will be NUL-terminated.

The fkid[] must accommodate both the database name (which is already
encoded in my_charset_filename) and the constraint name
(which must be converted to my_charset_filename) so that we can check
if it is in the format databasename/tablename_ibfk_1 (all encoded in
my_charset_filename).

Modern software (including text editors, static analysis software,
and web-based code review interfaces) often requires source code files
to be interpretable via a consistent character encoding, with UTF-8 or
ASCII (a strict subset of UTF-8) as the default. Several of the MariaDB
source files contain bytes that are not valid in either the UTF-8 or
ASCII encodings, but instead represent strings encoded in the
ISO-8859-1/Latin-1 or ISO-8859-2/Latin-2 encodings.

These inconsistent encodings may prevent software from correctly
presenting or processing such files. Converting all source files to
valid UTF8 characters will ensure correct handling.

Comments written in Czech were replaced with lightly-corrected
translations from Google Translate. Additionally, comments describing
the proper handling of special characters were changed so that the
comments are now purely UTF8.

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.
Co-authored-by: Andrew Hutchings <andrew@linuxjedi.co.uk>

trx_undo_page_report_rename(): Use the correct maximum length of
a table name. Both the database name and the table name can be up to
NAME_CHAR_LEN (64 characters) times 5 bytes per character in the
my_charset_filename encoding. They are not encoded in UTF-8!

fil_op_write_log(): Reserve the correct amount of log buffer for
a rename operation. The file name will be appended by
mlog_catenate_string().

rename_file_ext(): Reserve a large enough buffer for the file names.

take into account C/C specific CR_ERR_NET_WRITE error

MDEV-18873 Server crashes in Compare_identifiers::operator or in my_strcasecmp_utf8 upon ADD PERIOD IF NOT EXISTS with empty name

empty identifier specified as `` ends up with a NULL LEX_CSTRING::str in lexer.
This is not considered correct in upper layers, for example in Compare_identifiers::operator().
Empty column name is usually avoided by a check_column_name() call while parsing,
and period name matches the column name completely.
Hence, this fix uses the mentioned call for verification, too.

In commit 0b47c126 (MDEV-13542)
a few calls to mtr_t::memo_push() were moved before a write latch
on the page was acquired. This introduced a race condition:

1. is_block_dirtied() returned false to mtr_t::memo_push()
2. buf_page_t::write_complete() was executed, the block marked clean,
and a page latch released
3. The page latch was acquired by the caller of mtr_t::memo_push(),
and mtr_t::m_made_dirty was not set even though the block is in
a clean state.

The impact of this race condition is that crash recovery and backups
may fail.

btr_cur_latch_leaves(), btr_store_big_rec_extern_fields(),
btr_free_externally_stored_field(), trx_purge_free_segment():
Acquire the page latch before invoking mtr_t::memo_push().
This fixes the regression caused by MDEV-13542.

Side note: It would suffice to set mtr_t::m_made_dirty at the time
we set the MTR_MEMO_MODIFY flag for a block. Currently that flag is
unnecessarily set if a mini-transaction acquires a page latch on
a page that is in a clean state, and will not actually modify the block.
This may cause unnecessary acquisitions of log_sys.flush_order_mutex
on mtr_t::commit().

mtr_t::free(): If the block had been exclusively latched in this
mini-transaction, set the m_made_dirty flag so that the flush order mutex
will be acquired during mtr_t::commit(). This should have been part of
commit 4179f93d (MDEV-18976).
It was necessary to change mtr_t::free() so that
WriteOPT_PAGE_CHECKSUM::operator() would be able to avoid writing
checksums for freed pages.

Since the 10.5 split of the privileges, the required GRANTs
for various mariabackup operations has changed.

In the addition of tests, a number of mappings where incorrect:

The option --lock-ddl-per-table didn't require connection admin.

The option --safe-slave-backup requires SLAVE MONITOR even without
the --no-lock option.

This bug affected some queries with an IN/ALL/ANY predicand or an EXISTS
predicate whose subquery contained a GROUP BY clause that could be
eliminated. If this clause used a IN/ALL/ANY predicand whose left operand
was a single-value subquery then execution of the query caused a crash of
the server after invokation of remove_redundant_subquery_clauses().
The crash was caused by an attempt to exclude the unit for the single-value
subquery from the query tree for the second time by the function
Item_subselect::eliminate_subselect_processor().

This bug had been masked by the bug MDEV-28617 until a fix for the latter
that properly excluded units was pushed into 10.3.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

buf_defer_drop_ahi(): Remove. Ever since
commit c7f8cfc9 (MDEV-27700)
it is safe to invoke btr_search_drop_page_hash_index(block, true)
to remove an orphan adaptive hash index.

Any attempt to upgrade page latches is prone to deadlocks. Recently,
we observed a few hangs that involved nothing more than a small table
consisting of one clustered index page, one secondary index page and
some undo pages.

followup for "remove invalid options from warning messages"

The issue is that trx_t::lock.was_chosen_as_deadlock_victim can be reset
before the transaction check it and set trx_t::error_state.

The fix is to reset trx_t::lock.was_chosen_as_deadlock_victim only in
trx_t::commit_in_memory(), which is invoked on full rollback. There is
also no need to have separate bit in
trx_t::lock.was_chosen_as_deadlock_victim to flag transaction it was
chosen as a victim of Galera conflict resolution, the same variable can be
used for both cases except debug build. For debug build we need to
distinguish deadlock and Galera's abort victims for debug checks. Also
there is no need to check for deadlock in lock_table_enqueue_waiting() for
Galera as the coresponding check presents in lock_wait().

Local variable "error_state" in lock_wait() was replaced with
trx->error_state, because before the replace
lock_sys_t::cancel<false>(trx, lock) and lock_sys.deadlock_check() could
change trx->error_state, which then could be overwritten with the local
"error_state" variable value.

The lock_wait_suspend_thread_enter DEBUG_SYNC point name is misleading,
because lock_wait_suspend_thread was eliminated in e71e6133. It was renamed
to lock_wait_start.

Reviewed by: Marko Mäkelä, Jan Lindström.

Removed use std::vector's ba push_back(), pop_back() to  make it more
obvious that memory in the vectors won't be reallocated.

Also, "borrowed" elements can be debugged a little better now,
they are put into the start of the m_cache vector.