There are no source code changes in this commit!
This is an empty follow-up commit for
  284ac6f2
to comment what was done, as the patch itself did not have
change comments.

Problems solved in this patch:

1. The function calc_hash_for_unique() erroneously takes into account
the string length, so equal strings (in terms of the collation)
with different lengths got different hash value.

For example:
- LATIN LETTER A             - 1 byte
- LATIN LETTER A WITH ACUTE  - 2 bytes

are equal in utf8_general_ci, but as their lengths
are different, calc_hash_for_unique() returned
different hash values.

2. calc_hash_for_unique() also erroneously used val_str()
result to calculate hashes. This may not be correct for
some data types, e.g. TIMESTAMP, as its string
value depends on the session environment (e.g. @@time_zone).

Change summary:

Instead of doing Item::val_str(), we should always call
Field::hash() of the underlying Field. It properly
handles both cases (equal strings with different
lengths, as well as tricky data types like TIMESTAMP).

Detailed change description:

Non-functional changes (make the code cleaner):

- Adding a helper class Hasher, to pass hash parts
  nr1 and nr2 through function arguments easier.
- Splitting virtual Field::hash() into non-virtual
  wrapper Field::hash() and virtual Field::hash_not_null().
  This helps to get rid of duplicate code handling SQL NULL,
  as it was equal in all Field_xxx implementations.
- Adding a new method THD::my_ok_with_recreate_info().

Actual fix changes (make new tables work properly):

- Adding a virtual method Item::hash_not_null()
  This helps to handle hashes on full fields (Item_field)
  and hashes on prefix fields (Item_func_left(Item_field))
  in a polymorphic way.
  Implementing overrides for Item_field and Item_func_left.

- Rewriting Item_func_hash::val_int() to use Item::hash_not_null(),
  instead of the combination of val_str() and alc_hash_for_unique().

Backward compatibility changes (make old tables work in the new server):

- Adding a new class Item_func_hash_mariadb_100403.
  Moving the old version of Item_func_hash::val_int()
  into Item_func_hash_mariadb_100403::val_int().
  The old class Item_func_hash_mariadb_100403 is still needed,
  to open old tables before upgrade is done.

- Adding TABLE_SHARE::old_long_hash_function() and
  handler::check_long_hash_compatibility() to test
  if a table is using an old hash function.

- Adding a helper method TABLE_SHARE::make_long_hash_func()
  to instantiate either Item_func_hash_mariadb_100403 (for old
  not upgraded tables) or Item_func_hash (for new tables).

Upgrade changes (make old tables upgrade in the new server properly):

Upgrading an old table to a new hash can be done using either
of these two statements:

  ALTER IGNORE TABLE t1 FORCE;
  REPAIR TABLE t1;

!!! These statements find and filter out erreneous duplicates!!!
The table after these statements will have less records
if there were erroneous duplicates (such and A and A WITH ACUTE).

The information about filtered out records is reported in both statements.

- Adding a new class Recreate_info to return out information
  about copied and duplucate rows from these functions:
  - mysql_alter_table()
  - mysql_recreate_table()
  - admin_recreate_table()
  This helps to print a warning during REPAIR:

MariaDB [test]> repair table mdev27653_100422_text;
+----------------------------+--------+----------+------------------------------------+
| Table                      | Op     | Msg_type | Msg_text                           |
+----------------------------+--------+----------+------------------------------------+
| test.mdev27653_100422_text | repair | Warning  | Number of rows changed from 2 to 1 |
| test.mdev27653_100422_text | repair | status   | OK                                 |
+----------------------------+--------+----------+------------------------------------+
2 rows in set (0.018 sec)

When built with ubsan and trying to load the spider plugin, the hidden
visibility of mysqld compiling flag causes ha_spider.so to be missing
the symbol ha_partition. This commit fixes that, as well as some
memcpy null pointer issues when built with ubsan.
Signed-off-by: Yuchen Pei <yuchen.pei@mariadb.com>

MySQL 5.7.41 includes one InnoDB change
mysql/mysql-server@d2d6b2dd00f709bc528386009150d4bc726e25a0
that seems to be applicable to MariaDB Server 10.3 and 10.4.
Even though commit 5b9ee8d8
seems to have fixed sporadic failures on our CI systems, it is
theoretically possible that another race condition remained.

buf_flush_page_cleaner_coordinator(): In the final loop,
wait also for buf_get_n_pending_read_ios() to reach 0.
In this way, if a secondary index leaf page was read into the
buffer pool and ibuf_merge_or_delete_for_page() modified that
page or some change buffer pages, the flush loop would execute
until the buffer pool really is in a clean state.

This potential data corruption bug does not affect MariaDB Server 10.5
or later, thanks to commit b42294bc
which removed change buffer merges that are not explicitly requested.

If two high priority threads have lock conflict, we look at the
order of these transactions and honor the earlier transaction.
for_locking parameter in lock_rec_has_to_wait() has become
obsolete and it is now removed from the code .
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

The rather recent thd_need_ordering_with() function does not take
high priority transactions' order in consideration. Chaged this
funtion to compare also transaction seqnos and favor earlier transaction.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

This commit contains only a mtr test for reproducing the issue in MDEV-29512
The actual fix will be pushed in wsrep-lib repository

The hanging in MDEV-29512 happens when binlog purging is attempted, and there is
one local BF aborted transaction waiting for commit monitor.

The test will launch two node cluster and enable binlogging with expire log days,
to force binlog purging to happen.
A local transaction is executed so that will become BF abort victim, and has advanced
to replication stage waiting for commit monitor for final cleanup (to mark position in innodb)
after that, applier is released to complete the BF abort and due to binlog configuration,
starting the binlog purging. This is where the hanging would occur, if code is buggy
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Created mtr test for reproducing the crash

Developed actual fix for the issue.
Setting THD::system_thread_info.rpl_sql_info for replayer thread,
same way as it is handled for appliers.

Recorded test result, with the fix
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Cluster conflict victim's THD is marked with wsrep_aborter.
THD::wsrep_aorter holds the thread ID of the hight priority tread,
which is currently carrying out BF aborting for this victim.

However, the BF abort operation is not always successful,
and in such case the wsrep_aborter mark should be removed.
In the old code, this wsrep_aborter resetting did not happen,
and this could lead to a situation where the sticky wsrep_aborter
mark prevents any further attempt to BF abort this transaction.

This commit fixes this issue, and resets wsrep_aborter after
unsuccesful BF abort attempt.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

node->is_delete was incorrectly set to NO_DELETE for a set of operations.

In general we shouldn't rely on sql_command and look for more abstract ways
to control the behavior.

trg_event_map seems to be a suitable way. To mind replica nodes, it is ORed
with slave_fk_event_map, which stores trg_event_map when replica has
triggers disabled.

Signed-off-by: lilinjie <lilinjie@uniontech.com>

This only happens with 'timestamp_column IN (select ...)

The reason was a missing assignment in Item_cache_timestamp::cache_value()

MDEV-25277: mysqlbinlog --verbose cannot read row events with compressed columns: Don't know how to handle column type: 140

Problem:
=======
Mysqlbinlog cannot show the type of a compressed
column when two levels of verbosity is provided.

Solution:
========
Extend the log event printing logic to handle and
tag compressed types.

Behavioral Changes:
==================
  Old: When mysqlbinlog is called in verbose mode and
the database uses compressed columns, an error is
returned to the user.

  New: The output will append “ COMPRESSED” on the
type of compressed columns

Reviewed By
===========
Andrei Elkin <andrei.elkin@mariadb.com>

This commit adds support for the --aria-log-dir-path
option on the command line and for the aria-log-dir-path
option in the configuration file to the SST scripts, since
before this change these parameters were completely ignored
during SST - SST scripts assumed that aria logs files are
always located in the same directory as logs for innodb.

Tests for this change will be added as a separate commit,
along with tests for MDEV-30157 and MDEV-28669.

This fix adds separate handling for "undo*" files that contain undo
logs as part of innodb files and adds a filter for undo* to the main
filter used when initially transferring files with rsync.

This commit adds even more correct handling of parameters
with paths when they contain leading or trailing spaces and/or
slashes. Also it fixes problems that occur when the user specified
explicit paths to additional directories, but these paths match
the specified path of the data directory - in this case, additional
subdirectories should be treated (in relation to the data directory)
in the same way as if these paths were not specified or as if they
are implicitly specified as "." or "./". But prior to this fix,
existing code treated any values as if they were completely
separate directories, whether or not they actually point to the
same location to which datadir points to - and this sometimes
resulted in incorrect file transfers.

This fix does not contain separate tests, as tests will be
part of the main commit(s). This fix has been made as a separate
commit to facilitate review for major substantive fixes related
to MDEV-30157 and MDEV-28669.

(Variant 3, initial variant was by Rex Jonston)

A LEFT JOIN with a constant as a column of the inner table produced wrong
query result if the optimizer had to write the inner table column into a
temp table. Query pattern:

  SELECT ...
  FROM (SELECT /*non-mergeable select*/
        FROM t1 LEFT JOIN (SELECT 'Y' as Val) t2 ON ...) as tbl

Fixed this by adding Item_direct_view_ref::save_in_field() which follows
the pattern of Item_direct_view_ref's save_org_in_field(),
save_in_result_field() and val_XXX() functions:
* call check_null_ref() and handle NULL value
* if we didn't get a NULL-complemented row, call Item_direct_ref's function.

lock_rec_has_to_wait(): Remove the unused parameter for_locking
that had been originally added
in commit df4dd593

clang15 finally errors on old prototype definations.

Its also a lot fussier about variables that aren't used
as is the case a number of time with loop counters that
aren't examined.

RocksDB was complaining that its get_range function was
declared without the array length in ha_rocksdb.h. While
a constant is used rather than trying to import the
Rdb_key_def::INDEX_NUMBER_SIZE header (was causing a lot of
errors on the defination of other orders). If the constant
does change can be assured that the same compile warnings will
tell us of the error.

The ha_rocksdb::index_read_map_impl DBUG_EXECUTE_IF was similar
to the existing endless functions used in replication tests.
Its rather moot point as the rocksdb.force_shutdown test that
uses myrocks_busy_loop_on_row_read is currently disabled.

it's incorrect to use change_item_tree() to replace arguments
of top-level AND/OR, because they (arguments) are stored in a List,
so a pointer to an argument is in the list_node, and individual
list_node's of top-level AND/OR can be deleted in Item_cond::build_equal_items().
In that case rollback_item_tree_changes() will modify the deleted object.

Luckily, it's not needed to use change_item_tree() for top-level
AND/OR, because the whole top-level item is copied and preserved
in prep_where and prep_on, and restored from there.

So, just don't.

Additionally to the test case in the commit it fixes
* ASAN failure of main.opt_tvc --ps
* ASAN failure of main.having_cond_pushdown --ps

remove casts. uchar can store 1/0 as good as bool.

when an internal temporary table field is created from a real field,
a new temp field should only copy a default from the source field
when the latter has it

when creating a temp table field from an actual table field,
these two fields are supposed to be mostly identical
(except for BIT field storage), in particular, temp field should
have the same default as the orig field, even if the sql_mode has
been changed meanwhile (e.g. to include NO_ZERO_DATE)

Helper class to swicth to relaxed checks during field copy.
Temporarily.

regression from MDEV-29540 / 8c389393.

INSERT SELECT errors needed to be unconditionally ignored.

As this touches the CREATE .. SELECT functionality, show
the equalivent test there.

Don't display the source revision in the mysqld --help output.

This bug affected queries with nested left joins having the same last inner
table such that not_exists optimization could be applied to the most inner
outer join when optimizer chose to use join buffers. The bug could lead to
producing wrong a result set.
If the WHERE condition a query contains a conjunctive IS NULL predicate
over a non-nullable column of an inner table of a not nested outer join
then not_exists optimization can be applied to tho the outer join. With
this optimization when looking for matches for a certain record from the
outer table of the join the records of the inner table can be ignored
right after the first match satisfying the ON condition is found.
In the case of nested outer joins having the same last inner table this
optimization still can be applied but only if all ON conditions of the
embedding outer joins are satisfied. Such check was missing in the code
that tried to apply not_exists optimization when join buffers were used
for outer join operations.
This problem has been already fixed in the patch for bug MDEV-7992. Yet
there it was resolved only for the cases when join buffers were not used
for outer joins.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

MariaDB MDEV-12583 added `SOURCE_REVISION` variable that exposes the
SHA1 of source code commit that the current running engine was built
from. This info is useful for troubleshooting and debugging.

This commit does the following:
- addes the `SOURCE_REVISION` value into engine error log.
- when a crash triggers handle_fatal_signal, the `SOURCE_REVISION` will
  be included in crash report.
- resolves MDEV-20344: startup messages belong in stderr/error-log not
  stdout

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.