Otherwise it could cause false negative when ddl recovery done is part
of the plugin initialization

Commit a8a75ba2 causes the MariaDB server to crash, usually with signal
11, at random code locations due to invalid pointer values during any
table operation. This issue occurs when the server is built with -O3 and
other customized compiler flags.

For example, the command `use db1;` causes server to crash in the
`check_table_access` function at line sql_parse.cc:7080 because
`tables->correspondent_table` is an invalid pointer value of 0x1.

The crashes are due to undefined behavior from using uninitialized
variables. The problematic commit a8a75ba2 introduces code that
allocates memory and sets it to 0 using thd->calloc before initializing
it with a placement new operation.
This process depends on setting memory to 0 to initialize member
variables not explicitly set in the constructor. However, the compiler
can optimize out the memset/bfill, leading to uninitialized values and
unpredictable issues.

Once a constructor function initializes an object, any uninitialized
variables within that object are subject to undefined behavior. The
state of memory before the constructor runs, whether it involves
memset or was used for other purposes, is irrelevant after the
placement new operation.

This behavior can be demonstrated with this
[test](https://gcc.godbolt.org/z/5n87z1raG) I wrote to examine the
assembly code. The code in MariaDB can be abstracted to the following,
though it has many layers wrapped around it and more complex logic,
causing slight differences in optimization in the MariaDB build.
To summarize, on x86, the memset in the following code is optimized out
with both -O2 and -O3 in GCC 13, and is only preserved in the much older
GCC 4.9.

    struct S {
      int i;     // uninitialized in consturctor
      S() {};
    };
    int bar() {
      void *buf = malloc(sizeof(S));
      memset(buf, 0, sizeof(S));       // optimized out
      S* s = new(buf) S;
      return s->i;
    }

With GCC13 -O3:

    bar():
          sub     rsp, 8
          mov     edi, 4
          call    malloc
          mov     eax, DWORD PTR [rax]
          add     rsp, 8
          ret

With GCC4.9 -O3

    bar():
          sub     rsp, 8
          mov     edi, 4
          call    malloc
          mov     DWORD PTR [rax], 0
          xor     eax, eax
          add     rsp, 8
          ret

Now we ensure the constructor initializes variables correctly by running
the reset() function in the constructor to perform the memset/bfill(0)
operation. After applying the fix, the crash is gone.

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.

During InnoDB root page split, InnoDB does the following
1) First move the root records to the new page(p1)
2) Empty the root, insert the node pointer to the root page
3) Split the new page and make it as child nodes.
4) Finds the split record, allocate another new page(p2)
to the index
5) InnoDB stores the record(ret) predecessor to the supremum
record of the page (p2).
6) In page_copy_rec_list_start(), move the records from p1 to p2
upto the split record
6) Given table is a compressed row format page, InnoDB attempts to
compress the page p2 and failed (due to innodb_compression_level = 0)
7) Since the compression fails, InnoDB gets the number of preceding
records(ret_pos) of a record (ret) on the page (p2)
8) Page (p2) is a new page, ret points to infimum record.
ret_pos can be 0. InnoDB have wrong condition that ret_pos shouldn't
be 0 and returns corruption. InnoDB has similar wrong check in
page_copy_rec_list_end()

(With trivial fixes by sergey@mariadb.com)
Added option fix_innodb_cardinality to optimizer_adjust_secondary_key_costs

Using fix_innodb_cardinality disables the 'divide by 2' of rec_per_key_int
in InnoDB that in effect doubles the Cardinality for secondary keys.
This has the biggest effect for indexes where a few rows has the same key
value. Using this may also cause table scans for very small tables (which
in some cases may be better than an index scan).

The user visible effect is that 'SHOW INDEX FROM table_name' will for
InnoDB show the true Cardinality (and not 2x the real value). It will
also allow the optimizer to chose a better index in some cases as the
division by 2 could have a bad effect for tables with 2-5 identical values
per key.

A few notes about using fix_innodb_cardinality:
- It has direct affect for SHOW INDEX FROM table_name. SHOW INDEX
  will also update the statistics in table share.
- The effect of fix_innodb_cardinality for query plans or EXPLAIN
  is only visible after first open of the table. This is why one must
  do a flush tables or use SHOW INDEX for the option to take effect.
- Using fix_innodb_cardinality can thus affect all user in their query
  plans if they are using the same tables.

Because of this, it is strongly recommended that one uses
optimizer_adjust_secondary_key_costs=fix_innodb_cardinality mainly
in configuration files to not cause issues for other users.

- This issue is caused by commit e71e6133
(MDEV-24671). Change the output of transaction lock wait
time in microseconds suffix.

Allow the NAME_CONST unwrap optimization when the client is not
in the PREPARE step of prepared statement nor in the view
analysis mode.

When mysqldump is run to dump the `mysql` system database, it generates
INSERT statements into the table `mysql.gtid_slave_pos`.
After running the backup script
those inserts did not produce the expected gtid state on slave. In
particular the maximum of mysql.gtid_slave_pos.sub_id did not make
into
   rpl_global_gtid_slave_state.last_sub_id

an in-memory object that is supposed to match the current state of the
table. And that was regardless of whether --gtid option was specified
or not. Later when the backup recipient server starts as slave
in *non-gtid* mode this desychronization may lead to a duplicate key
error.

This effect is corrected for --gtid mode mysqldump/mariadb-dump only
as the following.  The fixes ensure the insert block of the dump
script is followed with a "summing-up" SET @global.gtid_slave_pos
assignment.

For the implemenation part, note a deferred print-out of
SET-gtid_slave_pos and associated comments is prefered over relocating
of the entire blocks if (opt_master,slave_data &&
do_show_master,slave_status) ...  because of compatiblity
concern. Namely an error inside do_show_*() is handled in the new code
the same way, as early as, as before.

A regression test can be run in how-to-reproduce mode as well.
One affected mtr test observed.
rpl_mysqldump_slave.result "mismatch" shows now the new deferring print
of SET-gtid_slave_pos policy in action.

Additional tests for MDEV-28345 ASAN: use-after-poison or unknown-crash in my_strtod_int from charset_info_st::strntod or test_if_number

The test was missing a save_master_gtid.inc on the master,
leading to the slave thinking it was in sync after executing
sync_with_master_gtid.inc, despite not having executed the
latest transaction. This skipped transaction, XA COMMIT,
was supposed to error-to-be-ignored because its XID could not
be found, but be thrown out because the replication filters
would filter out the target database. However, if the slave
was able to stop before executing the transaction, then
the replication filer is reset (to empty), and when the
slave is later restarted, that transactions error would
no longer be ignored.

Additionally, as the test cases added in MDEV-33921 rely
on GTID synchronization, the test cases now force
master_use_gtid=slave_pos for consistency

This reverts commit 938b9293. Not needed after 90d376e0.

quote a database name in the slow log

remove it

refine mariadb-backup password zapping check

protect MariaDB conditional comments from a bug
in Percona MySQL comment parser

for ALTER_PARTITION_ADMIN (CHECK/REPAIR/LOAD INDEX/CACHE INDEX/etc)
partitioning marks affected partitions with PART_ADMIN state.

The assumption is that the server will call a corresponding
method of ha_partition which will reset the state back to PART_NORMAL.

This assumption is invalid, the server is not required to do so,
indeed, in CHECK ... FOR UPGRADE the server might decide early that
the table is fine and won't call ha_partition::check(), leaving
partitions in the wrong state. It will thus leak into the next
statement confusing the engine about what it is doing (see
ha_partition::create_handler_file()), causing a crash later.

Let's force all partitions into PART_NORMAL state after the admin
operation succeeded, in case it did so without consulting the engine.

There are 3 diff in result:
1) NULL value from SELECT
Due to incorrect truncating of the hex value, incorrect value is
written instead of original value to the view frm. This results in reading
incorrect value from frm, so eventual result is NULL.
2) 'Name_exp1' in column name (in gis.test)
This was because the identifier in SELECT is longer than 64 characters,
so 'Name_exp1' alias is also written to the view frm.
3)diff in explain extended
This was because the query plan for view protocol doesn't
contain database name. As a fix, disable view protocol for that particular
query.

Import only the required functions instead of all the functions from the
module to reduce the unnecessary functions in the namespace and prevent
shadowing. Note: All code changes are non-functional.

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.

> After May 31, 2024, CentOS Stream 8 will be archived and no further
updates will be provided. [1]

CentOS Stream 8 is now EOL and should be updated to using CentOS Stream
9 for compatibility testing in GitLab CI.

[1] https://blog.centos.org/2023/04/end-dates-are-coming-for-centos-stream-8-and-centos-linux-7/
https://www.centos.org/centos-linux-eol/

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.

MDEV-28345 ASAN: use-after-poison or unknown-crash in my_strtod_int from charset_info_st::strntod or test_if_number

This patch fixes two problems:

- The code inside my_strtod_int() in strings/dtoa.c could test the byte
  behind the end of the string when processing the mantissa.
  Rewriting the code to avoid this.

- The code in test_if_number() in sql/sql_analyse.cc called my_atof()
  which is unsafe and makes the called my_strtod_int() look behind
  the end of the string if the input string is not 0-terminated.
  Fixing test_if_number() to use my_strtod() instead, passing the correct
  end pointer.

Mroonga UDFs can't be used without loading Mroonga.

Specifying filters (filter_status, filter_user, etc) in the mytop config
previously wouldn't work, because any filter specified here was added to
the config hash as a literal string.

This change fixes that - if filter_* is defined in the config and matches
an existing filter_* key, then run the value through StringOrRegex() and
assign to the config hash.

Item_exists_subselect::fix_length_and_dec() sets explicit_limit to 1.
In the exists2in transformation it resets select_limit to NULL. For
consistency we should reset explicity_limit too.

This fixes a bug where spider table returns wrong results for queries
that gets through exists2in transformation when semijoin is off.

To avoid off-by-one in spider_get_share.

And document conn key and conn key length.

Distinguish them in two place:

when constructing connection key in create_conn_key and
spider_create_conn for both ordinary queries and spider_direct_sql

For spider_create_conn and spider_udf_direct_sql_create_conn, the
created conn gets assigned a field from the source object if and only
if source->field is non-null.

For spider_create_conn_keys and spider_udf_direct_sql_create_conn_key,
we update the encoding so that absence of keyword and keyword with an
empty value result in different keys. More specifically, if the i-th
keyword has a value, the corresponding part in the conn key begins
with the char \i, followed by the possibly empty value and ends with a
\0. If the i-th keyword is not specified, then it does not get a
mention in the conn key.

As part of this change, we also update table param / option parsing to
recognise a singleton empty string when creating an string list,
instead of writing it off as NULL.

When connection parameters are specified in COMMENT, CONNECTION and
SERVER, they are overriden in the following order:

COMMENT > CONNECTION > SERVER

Blindly recursive chown is not way to do it.
This Workaround is not much better than just chown -R but
there is small adjustment just chown MariaDB statedir and logdir
then with find only chown those files that are not correctly
owned.

Fixes lintian warnings:
 * W: mariadb-server: recursive-privilege-change "chown -R" [postinst:*]
 * W: mariadb-server: recursive-privilege-change "chown -R" [postinst:*]

- Fix view-protocol: long expressions in SELECT
  list should have "expr AS column_name".

- Also, moved the test from subselect*test to
  suite/json/t/json_table.test.

Based on the current logic, objects of classes Item_func_charset and
Item_func_coercibility (responsible for CHARSET() and COERCIBILITY()
functions) are always considered constant.
However, SQL syntax allows their use in a non-constant manner, such as
CHARSET(t1.a), COERCIBILITY(t1.a).

In these cases, the `used_tables()` parameter corresponds to table names
in the function parameters, creating an inconsistency: the item is marked
as constant but accesses tables. This leads to crashes when
conditions with CHARSET()/COERCIBILITY() are pushed into derived tables.

This commit addresses the issue by setting `used_tables()` to 0 for
`Item_func_charset` and `Item_func_coercibility`. Additionally, the items
now store the return values during the preparation phase and return
them during the execution phase. This ensures that the items do not call
its arguments methods during the execution and are truly constant.

Reviewer: Alexander Barkov <bar@mariadb.com>

ENGINE_SUBSTITUTION only applies to CREATE TABLE and ALTER TABLE, and
Storage_engine_name::resolve_storage_engine_with_error() could be
called when executing any sql command.

SPIDER_CONN::loop_check_meraged_first is useless, because all
SPIDER_CONN_LOOP_CHECKs are in SPIDER_CONN::loop_check_queue, which in
spider_db_conn::fin_loop_check() is iterated over.

This fixes the use-after-free issue when there are three spider tables
sharing the same remote, and their corresponding
SPIDER_CONN_LOOP_CHECKs getting merged in
spider_conn_queue_and_merge_loop_check()

This also fixes MDEV-34555

Same cause as MDEV-31996. This prevents reuse of conns freed
previously, e.g. during the commit of previous statement.

It does not occur in 10.4 because of the commit for MDEV-19002 removed
the call to spider_check_trx_and_get_conn().