From 10.4.13, the `mariadb.sys` user was created to replace `root` definers.
 - In commit 0253ea7f, definer of
   Add/DropGeometryColumn procedures was changed to `mariadb.sys`, in
   `scripts/maria_add_gis_sp.sql.in`.
   However, maria_add_gis_sp.sql only applies to new databases created by
   installation script. Databases upgraded from old versions will miss this
   change.
 - In addition, according to commit
   0d6d801e(MDEV-23102), in some scenarios
   when root user is replaced it will skip creating `mariadb.sys` user.

This commit is to update the definer from `root` to `mariadb.sys` during
upgrade. It only makes the change if the original definers are root.

Doesn't choose to execute `maria_add_gis_sp.sql` in upgrade script to
recreate the procedures is because of considering the scenarios of
MDEV-23102 that `root` user is replaced and `mariadb.sys` is not created.

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.

Sys_lc_messages, Sys_lc_time_names: Use offsetof(MY_LOCALE, ...)
because the type has standard layout.

mdl_hash_function(): Use plain offsetof; MDL_key has standard layout.

Currently, SST scripts assume that the filename specified in
the --log-bin-index argument either does not contain an extension
or uses the standard ".index" extension. Similar assumptions are
used for the log_bin_index parameter read from the configuration
file. This commit adds support for arbitrary extensions for the
index file paths.

If the server is started with the --innodb-force-recovery argument
on the command line, then during SST this argument can be passed to
mariabackup only at the --prepare stage, and accordingly it must be
removed from the --mysqld-args list (and it is not should be passed
to mariabackup otherwise).

This commit fixes a flaw in the SST scripts and add a test that
checks the ability to run the joiner node in a configuration that
uses --innodb-force-recovery=1.

MDEV-23805 simplified the treatment of empty tables during ALTER TABLE,
which could prevent the scenarios that were previously reported and
fixed as MDEV-16131 and MDEV-24730.

With the MDEV-23805 fix, the statement
SET DEBUG_SYNC = 'now WAIT_FOR copied';
could occasionally time out, depending on timing.
Apparently, there was a race condition where purge could resume
(and empty the table) before ALTER TABLE got the chance to execute.
We must prevent the purge of history from running before
ALTER TABLE has started executing.

fil_space_decrypt(): change signature to return status via dberr_t only.
Also replace impossible condition with an assertion and prove it via
test cases.

  This bug affected queries with two or more references to a CTE referring
another CTE if the definition of the latter contained an invocation of
a stored function that used a base table. The bug could lead to a bogus
error message or to an assertion failure.
  For any non-first reference to CTE cte1 With_element::clone_parsed_spec()
is called that parses the specification of cte1 to construct the unit
structure for this usage of cte1. If cte1 refers to another CTE cte2
outside of the specification of cte1 then With_element::clone_parsed_spec()
has to be called for cte2 as well. This call is made by the function
LEX::resolve_references_to_cte() within the invocation of the function
With_element::clone_parsed_spec() for cte1.
  When the specification of a CTE is parsed all table references encountered
in it must be added to the global list of table references for the query.
As the specification for the non-first usage of a CTE is parsed at a
recursive call of the parser the function With_element::clone_parsed_spec()
invoked at this recursive call should takes care of appending the list of
table references encountered in the specification of this CTE cte1 to the
list of table references created for the query. And it should do it after
the call of LEX::resolve_references_to_cte() that resolves references to
CTEs defined outside of the specification of cte1 because this call may
invoke the parser again for specifications of other CTEs and  the table
references from their specifications must ultimately appear in the global
list of table references of the query.
  The code of With_element::clone_parsed_spec() misplaced the call of
LEX::resolve_references_to_cte(). As a result LEX::query_tables_last used
for the query that was supposed to point to the field 'next_global' of the
last element in the global list of table references actually pointed to
'next_global' of the previous element.
  The above inconsistency certainly caused serious problems when table
references used in the stored functions invoked in cloned specifications
of CTEs were added to the global list of table references.

- In ha_innobase::prepare_inplace_alter_table(), InnoDB should
check whether the table is empty. If the table is empty then
server should avoid downgrading the MDL after prepare phase.
It is more like instant alter, does change only in dicationary
and metadata.

- Changed few debug test case to make non-empty DDL table

Upon investigation, decided this to be a compiler bug
(happens with new compiler, on code that did not change for the last 15 years)

Fixed by de-optimizing single function remove_key(), using MSVC pragma

MDEV-26991: CURRENT_TEST: main.mysql_binary_zero_insert 'grep' is not recognized as an internal or external command, operable program or batch file.

Removed grep from mysqldump command stream and instead,
extend the search_file pattern to search for rows containing
binary zeros instead of any occurance of '00' in the input

If it is not enabled, build wsrep as static "stub" library from wsrep_dummy.cc
´

Allow static plugins to export symbols (on Unix)
wsrep_info relies on wsrep defined symbols (e.g  LOCK_wsrep_config_state)
exported from mysqld

Means, plugin will not be available in embedded, even if compiled-in

This reverts commit 1a3570de.

This reverts commit e45f7f48.

- Add unit test.

Code cleanup: Remove Json_writer::is_on_fmt_helper_call. We already
maintain this state in fmt_helper.

If it is not enabled, build wsrep as static "stub" library from wsrep_dummy.cc
´

Allow static plugins to export symbols (on Unix)
wsrep_info relies on wsrep defined symbols (e.g  LOCK_wsrep_config_state)
exported from mysqld

in test main.range_vs_index_merge one path requires named JSON object:
assert.c:0(.annobin_assert.c_end)[0x7fe9d2270a76]
sql/my_json_writer.cc:43(Json_writer::on_start_object())[0x555e284f048a]
sql/my_json_writer.cc:59(Json_writer::start_object())[0x555e284ee6e8]
sql/my_json_writer.h:377(Json_writer_object::Json_writer_object(THD*))[0x555e281dce11]
sql/opt_range.cc:5137(get_best_disjunct_quick(PARAM*, SEL_IMERGE*, double))[0x555e287c576b]
sql/opt_range.cc:5492(merge_same_index_scans(PARAM*, SEL_IMERGE*, TRP_INDEX_MERGE*, double))[0x555e287c6cf6]
sql/opt_range.cc:5287(get_best_disjunct_quick(PARAM*, SEL_IMERGE*, double))[0x555e287c607a]
sql/opt_range.cc:3000(SQL_SELECT::test_quick_select

another one requires unnamed JSON:
mariadbd: /home/name/server/sql/my_json_writer.cc:379: bool Single_line_formatting_helper::on_add_member(const char*, size_t): Assertion `state== INACTIVE || state ==
assert.c:0(.annobin_assert.c_end)[0x7f33d8df8a76]
sql/my_json_writer.cc:380(Single_line_formatting_helper::on_add_member(char const*, unsigned long))[0x558362f6a717]
sql/my_json_writer.cc:150(Json_writer::add_member(char const*, unsigned long))[0x558362f69a91]
sql/my_json_writer.cc:146(Json_writer::add_member(char const*))[0x558362f69a5f]
sql/my_json_writer.h:383(Json_writer_object::Json_writer_object(THD*, char const*))[0x558362ceccaa]
sql/opt_range.cc:5139(get_best_disjunct_quick(PARAM*, SEL_IMERGE*, double))[0x5583632407d0]
sql/opt_range.cc:3000(SQL_SELECT::test_quick_select

This fixes up commit d22c8cae