In commit 7a4fbb55 (MDEV-25105)
the innochecksum option --write (-w) was removed altogether.
It should have been made a Boolean option, so that old data files
may be converted to a format that is compatible with
innodb_checksum_algorithm=strict_crc32 by executing the following:

innochecksum -n -w ibdata* */*.ibd

It would be better to use an older-version innochecksum
for such a conversion, so that page checksums will be validated
before updating the checksum.

It never was possible for innochecksum to convert files to the
innodb_checksum_algorithm=full_crc32 format that is the default
for new InnoDB data files.

This also fixes MDEV-20198: Instant ALTER TABLE is not crash safe

InnoDB dictionary recovery wrongly used the READ UNCOMMITTED isolation
level, causing some mismatch. For example, if a table was renamed or
replaced in a transaction, according to READ UNCOMMITTED the table might
not exist at all.

We implement READ COMMITTED isolation level for accessing the dictionary
tables SYS_TABLES, SYS_COLUMNS, SYS_INDEXES, SYS_FIELDS, SYS_VIRTUAL,
SYS_FOREIGN, SYS_FOREIGN_COLS. For most of these tables, no secondary
index exists. For the secondary indexes (on SYS_TABLES.ID,
SYS_FOREIGN.FOR_NAME, SYS_FOREIGN.REF_NAME), we will always look up
the primary key in the clustered index and check if the record actually
is a committed version.

dict_check_sys_tables(): Recover tablespaces also from delete-marked
committed records, so that if a matching .ibd file exists, it will
be removed by fil_delete_tablespace() when the committed delete-marked
SYS_INDEXES record of the clustered index is purged
in row_purge_remove_clust_if_poss_low().

fil_ibd_open(): Change the Boolean parameter "validate" to a ternary
one, to suppress error messages when the file might not exist.
It is possible that a .ibd file was deleted and the server shut down
before the SYS_INDEXES and SYS_TABLES records were purged. Hence, if
dict_check_sys_tables() finds a committed delete-marked record,
we must not complain if the tablespace file is not found.
On Windows, we msut treat ERROR_PATH_NOT_FOUND (directory not found)
in the same way as ERROR_FILE_NOT_FOUND. This fixes a few failures where
a previous test successfully executed DROP DATABASE (and deleted all
files and the directory), but a committed delete-marked SYS_TABLES
record had not been purged before server restart.

dict_getnext_system_low(): Do not filter out delete-marked records.

dict_startscan_system(), dict_getnext_system(): Do filter out
delete-marked records, for accessing the INFORMATION_SCHEMA tables.

dict_sys_tables_rec_read(): Return the DB_TRX_ID of the committed
version of the record. This is needed in dict_load_table_low().

dict_load_foreign_cols(), dict_load_foreign(): Add a parameter for
the current transaction identifier. In some DDL operations, the
FOREIGN KEY constraints are being loaded from the data dictionary
before the DDL transaction has been committed. For SYS_FOREIGN
and SYS_FOREIGN_COLS, we must implement the special case of
READ COMMITTED that the changes of the uncommitted current transaction
are visible.

dict_load_foreign(): Validate the table name. We could find a
SYS_FOREIGN.ID via a committed delete-marked secondary index record
that does not match the REF_NAME or FOR_NAME of the secondary index record.

dict_load_index_low(): Optionally take the table as a parameter,
so that table->def_trx_id can be updated in case of a
committed delete-marked SYS_INDEXES record corresponding
to DROP INDEX, but not corresponding to an index stub of ADD INDEX.

dict_load_indexes(): Do not update table->def_trx_id
in case of delete-marked records.

rec_is_metadata(), rec_offs_make_valid(), rec_get_offsets_func(),
row_build_low(): Relax some assertions. We may now have
!index->is_instant() even if a metadata record is present in the index.
Previously, the recovery of instant ADD/DROP COLUMN assumed
that READ UNCOMMITTED of the data dictionary will be performed.
Now, we will have a READ COMMITTED copy of the data dictionary
cache, and a READ UNCOMMITTED copy of the metadata record.

btr_page_reorganize_low(): Correctly update the FIL_PAGE_TYPE
when rolling back an instant ADD/DROP COLUMN operation.

row_rec_to_index_entry_impl(): Relax some assertions,
and disallow accessing "extra" fields. This fixes the recovery
of a crash during an instant ADD COLUMN after a successful
instant DROP COLUMN, in the test innodb.instant_alter_crash.

Tested by: Matthias Leich

InnoDB background statistics recalculation may acquire
a metadata also on the table itself, not only on the tables
that store the statistics.

Hence, it is better to disable InnoDB persistent statistics altogether.
This fixes up commit 9b8d9a1d.

* prevent infinite recursion in beyond-EOF reads (when pread returns 0)
* reduce code duplication

followup for d7817382 and f4fb6cb3

buf_pool_t::watch_unset(): Reorder some code so that
no warning will be emitted in CMAKE_BUILD_TYPE=RelWithDebInfo.
It is unclear why invoking watch_is_sentinel() before accessing
the block descriptor state would make the warning disappear.

Fixing the version of debian/ubuntu dependencies in 10.6
removes the apt-cache checking of libpmem and liburing
dependencies.

By arranging the checks earliest to latest, we unconditionally
change the dependences in earlier versions, and in later versions
we perform architecture checks to see if there is a dependency
on this architecture before removing/changing.

This takes from the architecture information on Ubuntu[1,2]
and Debian[3,4].

[1] https://packages.ubuntu.com/search?suite=all&arch=any&searchon=names&keywords=liburing-dev
[2] https://packages.ubuntu.com/search?suite=all&arch=any&searchon=names&keywords=libpmem-dev
[3] https://packages.debian.org/search?suite=all&section=all&arch=any&searchon=names&keywords=liburing-dev
[4] https://packages.debian.org/search?suite=all&section=all&arch=any&searchon=names&keywords=libpmem-dev

While moving to a prescribed dependencies in MDEV-28011, an error was made
in the merge. The Ubuntu and Debian supported architectures of rocksdb-tools
are different and need to be treated as such.

This actually had no effect as our support of mariadb-plugin-rocksdb was never
different to the distro support of rocksdb-tools. Some notes where added
to this affect.

There is also nothing to do for Debian sid, and never should be.

The differentiation and grouping of distro codenames is for convenience in
merging upwards as more dependencies change across distro versions.

The fixing of versions rather than relying on apt-cache to be correct prevents
unstable changes between releases, and potentially uninstallable packages like
happened in MDEV-28014.

Correct comment about zstd to MDEV-16525

Analysis: utf8 character set is now utf8mb3 or utf8mb4. So charset_master
is not able to find utf8 at the beginning of test. Hence it skips the tests
that use charset_master.
Fix: rename utf8 to utf8mb3 in charset_master.

buf_page_get_zip(): Do not perform a system call inside a
memory transaction. Instead, if the page latch is unavailable,
abort the memory transaction and let the fall-back code path
wait for the page latch.

buf_pool_t::watch_remove(): Return the previous state of the block.

buf_page_init_for_read(): Use regular stores for moving the
buffer fix count of watch_remove() to the new block descriptor.

A more extensive version of this was reviewed by Daniel Black
and tested with Intel TSX-NI by Axel Schwenke and Matthias Leich.
My assumption that regular loads and stores would execute faster
in a memory transaction than operations like std::atomic::fetch_add()
turned out to be incorrect.

The call mtr.add_suppression() that was added
in commit 75b7cd68
for MemorySanitizer and Valgrind runs is causing
a result difference for the test rpl.rpl_gtid_stop_start.
Let us disable the binlog for executing that statement.

Also, the test perfschema.statement_program_lost_inst
would fail due to the changes to have_innodb.inc in this commit.
To compensate for that, we will make more --suite=perfschema
tests run without InnoDB, and explicitly enable InnoDB in
those tests that depend on a transactional storage engine.

S3 engine and libmarias3 don't compile on Windows

also fixes:
MDEV-28104 Typo in storage/maria/s3_func.c: 'FN_DECVHAR

A few regression tests invoke heavy flushing of the buffer pool
and may trigger warnings that tablespaces could not be deleted
because of pending writes. Those warnings are to be expected
during the execution of such tests.

The warnings are also frequently seen with Valgrind or MemorySanitizer.
For those, the global suppression in have_innodb.inc does the trick.

This was suggested by Sergei Golubhick.
Fixes up commit b91a123d

MDEV-21117 had to relax own events acceptance condition for a case
when a former semisync master server recovers after crash as the
semisync slave. That however admitted a possibility for endless event
"orbiting" in the non-strict slave gtid mode of semisync circular
setup.

The same server-id event termination is restored now for
the non-strict gtid mode to follow regular rules (that is it's ignored
unless @@global.replicate_same_server_id allows it in).

To address MDEV-21117 recovery agenda,
in the strict gtid mode and the transaction's gtid ordered strictly
greater than the current slave gtid state, the same server-id
transaction is accepted.

The gtid strict mode is safe to accept transactions even if
the slave state were not set correct by the user, e.g
at the former master.
An added test shows a typical out-of-order error at execution so
no data corruption is guaranteed in such a case.

The fix in commit 6e390a62 (MDEV-26772)
was a step to the right direction, but implemented incorrectly.
When an InnoDB persistent statistics table cannot be locked immediately,
we must not let row_mysql_handle_errors() to roll back the transaction.

lock_table_for_trx(): Add the parameter no_wait (default false)
for an immediate return of DB_LOCK_WAIT in case of a conflict.

ha_innobase::delete_table(), ha_innobase::rename_table():
Pass no_wait=true to lock_table_for_trx() when needed,
instead of temporarily setting THDVAR(thd, lock_wait_timeout) to 0.

Since Debian Sid now has MariaDB 10.6, we can't do any upgrade tests in
Debian Sid for the 10.5 branch anymore. It would just fail with downgrade
errors.

Also, since MariaDB 10.5 is no longer in Sid, we can't even test 10.5.x
to 10.5.y upgrades in Sid.

Instead the 10.5 branch salsa-ci.yml should run all builds and tests based
on Debian Bullseye, which has MariaDB 10.5 (only).

To achieve this, essentially sync most the the salsa-ci.yml contents from
https://salsa.debian.org/mariadb-team/mariadb-10.5/-/tree/bullseye

Also add a couple Lintian overrides to make Salsa-CI pass.

NOTE TO MERGERS: This commit is intended for the 10.5 branch only, do not
merge anything from it on 10.6 or any other branch.

In commit ab38b751
an added "goto err" would seemingly cause a read of
an uninitialized variable old_info if errpos>=5.

However, because we would have errpos=0 at that point,
there was no real error.

dict_get_and_save_data_dir_path(): Protect the operation with
dict_table_t::lock_mutex and avoid unnecessary memory allocation.

- InnoDB purge waits at resume_FTS() while shutting down.
This happens after altering the FTS innodb partition table.
stop_FTS() has been called for each partition, but it calls
resume_FTS() only once and it leads to hang during shutdown.
This issue was introduced by
commit 1bd681c8(MDEV-25506).

extra2_read_len resolved by keeping the implementation
in sql/table.cc by exposed it for use by ha_partition.cc

Remove identical implementation in unireg.h
(ref: bfed2c7d)

Uses 500M+ of memory by repeating an 8 byte sequence 62.5M times.

Reduce the number of repeats on string reduced by 100 times.

Tested by applying against the reverted MDEV-24909 code. 1000 times
reduction was too much, but 100 still managed to trigger the bug.

Per Marko's comment in JIRA, sql_kill is passing the thread id
as long long. We change the format of the error messages to match,
and cast the thread id to long long in sql_kill_user.

The 10.5 test error main.grant_kill showed up a incorrect
thread id on a big endian architecture.

The cause of this is the sql_kill_user function assumed the
error was ER_OUT_OF_RESOURCES, when the the actual error was
ER_KILL_DENIED_ERROR. ER_KILL_DENIED_ERROR as an error message
requires a thread id to be passed as unsigned long, however a
user/host was passed.

ER_OUT_OF_RESOURCES doesn't even take a user/host, despite
the optimistic comment. We remove this being passed as an
argument to the function so that when MDEV-21978 is implemented
one less compiler format warning is generated (which would
have caught this error sooner).

Thanks Otto for reporting and Marko for analysis.

buf_flush_freed_pages(): Assert that neither buf_pool.mutex
nor buf_pool.flush_list_mutex are held. Simplify the loops.
Return the tablespace and the number of pages written or punched.

buf_flush_LRU_list_batch(), buf_do_flush_list_batch():
Release buf_pool.mutex before invoking buf_flush_space().

buf_flush_list_space(): Acquire the mutexes only after invoking
buf_flush_freed_pages().

Reviewed by: Thirunarayanan Balathandayuthapani

fil_space_t::try_to_close(): Tolerate a tablespace that has no
data files attached. The function fil_ibd_create() initially
creates and attaches a tablespace with no files, and invokes
fil_space_t::add() later.

fil_node_open_file(): After releasing and reacquiring fil_system.mutex,
check if the file was already opened by another thread. This avoids
an assertion failure !node->is_open() in fil_node_open_file_low().

These failures were reproduced with the test
innodb.table_definition_cache_debug and the fix of MDEV-27985.

commit '6de482a6'

10.3 no longer errors in truncate_notembedded.test
but per comments, a non-crash is all that we are after.

Commit 6c39eaeb made the crash recovery dependent on server_id.
The crash recovery could fail when restoring a new instance from
original crashed data directory USING A NEW SERVER ID.

The issue doesn't exist in previous major versions before 10.6.

Root cause is when generating the input XID to be searched in the hash,
server id is populated with the current server id.
So if the server id changed when recovering, the XID couldn't be found
in the hash due to server id doesn't match.

This fix is to use original server id when creating the input XID
object in function `xarecover_do_commit_or_rollback`.

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.

- InnoDB fails to skip newly created column while checking for
change column when table is in redundant row format. This issue
is caused the MDEV-18035 (ccb1acbd)