warning C4390:  ';': empty controlled statement found; is this the intent?

buf_flush_write_block_low(): Assert that the FIL_PAGE_LSN is set
and is not less than buf_page_t::oldest_modification.

Before commit c0f47a4a (MDEV-12026)
introduced the innodb_checksum_algorithm=full_crc32 format,
it was impossible to tell if InnoDB data files contained garbage in
the FIL_PAGE_TYPE header field (and possibly other fields).
This is because before commit 3926673c
in MySQL 5.1.48, InnoDB would write uninitialized data to some fields,
and because there was no way to tell with which InnoDB version a data
file was created.

If fil_space_t::full_crc32() holds, the data file cannot contain
uninitialized garbage or invalid FIL_PAGE_TYPE, and thus
fil_block_check_type() should not be invoked to correct anything.

generalize the replacement

mariadb-conv does not need to be linked with the client library
it does not talk to the server

The original patch was made by Takashi Sasaki <tsasaki609@gmail.com>.

The log file is opened as root since commit bb7a70c9, so there is no need
to chown it.

fil_addr_t: Use exactly sized data types.

flst_read_addr(): Remove the unused parameter mtr.

page_offset(): Return uint16_t.

# Conflicts:
#	win/packaging/extra.wxs.in

- It is not enough to have  and DeleteSymlinks actions
because within the same installation some exes executables can be both
added and removed, which needs both adding and removing some symlinks.

Instead of CreateSymlinks, there is now FixSymlinks function, which
goes through the list, and adds or removes the symlinks as needed.

- Implemented rollback for symlink custom action.

- Generate list of symlinks in C++ file, using CMake, rather than storing
lists as MSI properties.

If a joined table is accessed by a full text index then now no range rowid
filter can be used when accessing the records of this table.

This bug was fixed by the patch for mdev-20056.
This commit adds only a test case with a query using a full text index
and a range condition for another index.

Revert part of commit 6cedb671
because it turns out to be theoretically impossible to parse a
ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC metadata record where
the variable-length fields in the PRIMARY KEY have been written
as nonempty strings.

- Replace "class Repeat_count" with function call.
  There is no reason for this class to exists. More complex and more
  code than doing a function!  In addition the code didn't match what
  the val() function was doing.

Other things:
- Fixed compiler failure in print_cached_tables_callback()

           in row_search_idx_cond_check

When usage of rowid filter is evaluated by the optimizer to join a table
to the current partial join employing a certain index it should be checked
that a key for at least the major component of this index can be constructed
using values from the columns of the partial join.

Added CreateSymlinks and DeleteSymlinks functions to
CustomAction.cpp. Extra.wxs.in calls them.

As noted in commit abd45cdc
a search with PAGE_CUR_GE may land on the supremum record on
a leaf page that is not the rightmost leaf page. This could occur
when all keys on the current page are smaller than the search key,
and the smallest key on the successor page is larger than the search key.

Hence, after a failed PAGE_CUR_GE search, assertions
btr_pcur_is_after_last_in_tree() are bogus
and should be replaced with btr_pcur_is_after_last_on_page().

Unsigned type while RHS expression could be less than 0.

Introduce memcpy_aligned<N>(), memcmp_aligned<N>(), memset_aligned<N>()
and use them for accessing InnoDB page header fields that are known
to be aligned.

MY_ASSUME_ALIGNED(): Wrapper for the GCC/clang __builtin_assume_aligned().
Nothing similar seems to exist in Microsoft Visual Studio, and the
C++20 std::assume_aligned is not available to us yet.

Explicitly specified alignment guarantees allow compilers to generate
faster code on platforms with strict alignment rules, instead of
emitting calls to potentially unaligned memcpy(), memcmp(), or memset().

This particular assertion happened when shutting down Innodb IO.IO shutdown properly waits for all IOs to finish


However there is a race condition -
right after releasing last IO slot and before decrementing task count
in group, pending_io_count will be 0, but tasks_running will be 1,
leading to assertion.

The fix is to make task_group destructor to wait for last running task
to finish.

It was mistakenly used by tdc_start_shutdown() to make sure TABLE_SHARE
gets evicted from table definition cache when it becomes unused. However
same effect is achieved by resetting tdc_size and tc_size.

Part of MDEV-17882 - Cleanup refresh version

After 7fb9d649 it is used only by ALTER/DROP SERVER, which most probably
wasn't intentional as Federated never supported delayed inserts anyway.

If delayed inserts will ever become an issue with ALTER/DROP SERVER, we
should kill them by acquiring X-lock instead.

Part of MDEV-17882 - Cleanup refresh version

It is never called after 7fb9d649, which makes the whole refresh version
infrastructure useless.

Removed:
- tdc_version_t
- TDC_VERSION_MAX
- tdc_version
- TDC_element::version
- tdc_increment_refresh_version()
- tdc_refresh_version()
- refresh_version argument of tdc_wait_for_old_version()
- Flush_commands status variable
- refresh version from COM_STATISTICS
- refresh version from dbug printouts

Part of MDEV-17882 - Cleanup refresh version

dict_stats_shutdown() can hang, waiting for timer callback to finish.
This happens because locks the same mutex, which can also used inside
timer callback, within dict_stats_schedule() function.

Fix is to make dict_stats_schedule() use mutex.try_lock() instead of
mutex.lock().

In the unlikely case of simultaneous dict_stats_schedule() setting
different timer delays, now the first one would win, which is fine.
Important is that shutdown won't hang.

We must relax too strict debug assertions. For latin1_swedish_ci,
mtype=DATA_CHAR or mtype=DATA_VARCHAR will be used instead of
mtype=DATA_MYSQL or mtype=DATA_VARMYSQL. Likewise, some changes of
dtype_get_charset_coll() do not affect the data type encoding,
but only any indexes that are defined on the column.

Charset::same_encoding(): Check whether two charset-collations have
the same character set encoding.

dict_col_t::same_encoding(): Check whether two character columns
have the same character set encoding.

dict_col_t::same_type(): Check whether two columns have a compatible
data type encoding.

dict_col_t::same_format(), dict_table_t::instant_column(): Do not
compare mtype or the charset-collation of prtype directly.
Rely on dict_col_t::same_type() instead.

dtype_get_charset_coll(): Narrow the return type to uint16_t.

This is a refined version of a fix that was developed by
Thirunarayanan Balathandayuthapani.

UPDATE, DELETE: replace linear search of current/historical records
with vers_setup_conds().

Additional DML cases in view.test

The original crash happened when async replication IO thread was updating mysql.gtid_slave_pos table. Operations on this table should remain node local, but it appears that protection (THD::wsrep_ignore_table flag) to prevent wsrep replication for this table mas missing for innodb write_row() and update_row().
It was somewhat difficult to reproduce the issue, because mtr seems to create the affected table mysql.gtid_log_pos as of Aria engine type, and Aria engine operations will not be replicated anyhow. It looks, though, that in release installation, mysql.gtid_slave_pos table is of InnoDB engine.
It was possible to trigger somewhat related problem by running test galera.galera_as_slave_gtid with configuration: gtid_pos_auto_engines=InnoDB. However, this test mode, causes earlier crash when replication background thread creates aditional table: mysql.gtid_slave_pos_InnoDB, and this table create triggered wsrep TOI replication, which also failed for assertion. Actually, async replication IO and background threads should not replicate anything to cluster.

This pull request contains new test galera.galera_as_slave_gtid_auto_engine, which basically just runs galera.galera_as_slave_gtid with configuration of gtid_pos_auto_engines=InnoDB.
Test galera.galera_as_slave_gtid is also modified for better code reuse.
Actual fix for MDEV-21096 is in storage/innobase/handler/ha_innodb.cc, where THD::wsrep_ignore_table flag is now honored before wsrep key population.
There is additional fix in sql/service_wsrep.cc where async replication IO and background threads are marked as non-local. This fences these threads out of wsrep replication altogether. Note that this change, actually makes the use of THD::wsrep_ignore-table redundant. We may want to refactor THD::wsrep_ignore_table out in the future, if there is no other use case for it in sight.

At each mini-transaction commit, the log sequence number of the
mini-transaction must be written to each modified page, so that
it will be available in the FIL_PAGE_LSN field when the page is
being read in crash recovery.

InnoDB was unnecessarily allocating redundant storage for the
field, in buf_page_t::newest_modification. Let us access
FIL_PAGE_LSN directly.

Furthermore, on ALTER TABLE...IMPORT TABLESPACE, let us write
0 to FIL_PAGE_LSN instead of using log_sys.lsn.

buf_flush_init_for_writing(), buf_flush_update_zip_checksum(),
fil_encrypt_buf_for_full_crc32(), fil_encrypt_buf(),
fil_space_encrypt(): Remove the parameter lsn.

buf_page_get_newest_modification(): Merge with the only caller.

buf_tmp_reserve_compression_buf(), buf_tmp_page_encrypt(),
buf_page_encrypt(): Define static in the same compilation unit
with the only caller.

PageConverter::m_current_lsn: Remove. Write 0 to FIL_PAGE_LSN
on ALTER TABLE...IMPORT TABLESPACE.

           in row_search_idx_cond_check

For a single table query with ORDER BY and several sargable range
conditions the optimizer may choose an execution plan that employs
a rowid filter. In this case it is important to build the filter before
calling the function JOIN_TAB::sort_table() that creates sort index
for the result set, because when this is index created the filter has
to be already filled. After the sort index has been created the
filter must be deactivated. If not to do this the innodb function
row_search_idx_cond_check() is getting confused when it has to read rows
from the created sort index by using ha_rnd_pos().
The order of actions mentioned above is needed also when processing a
join query if sorting is performed for the first non constant table in
the chosen execution plan.

Implement syntax like:

create table t1 (x int) with system versioning partition by system_time;

which will create 1 history partition and 1 current partition.
Also it is possible to specify the number of history partitions:

create table t1 (x int) with system versioning partition by system_time partitions 5;

which will create 4 history partitions (and 1 current partition).

Tests:
partition.test cases are duplicated where it is appropriate for default partitions.
partition_rotation.test cases are replaced by default partitions where possible.

Use my_localhost instead of NULL for share->hostname.

MDEV-18957 UPDATE with LIMIT clause is wrong for versioned partitioned tables

UPDATE, DELETE: replace linear search of current/historical records
with vers_setup_conds().

Additional DML cases in view.test

Closes #1405

Message "WSREP: Failed to apply write set" has been turned into an
error, but tests were not adjusted accordingly.

The block defining turn_parser_debug_on() now looks similar
in both sql_yacc.yy and sql_yacc_ora.yy.