The previous commit was erroneously marked as MDEV-23162.
The correct issue is MDEV-23478.

An alternative implementation (replacing the one based on repertoire).

This implementation makes Field send itself to Protocol_text using
data type specific Protocol methods rather than field->val_str()
followed by protocol_text->store_str().

As now Field sends itself in the same way to all protocol types
(e.g. Protocol_binary, Protocol_text, Protocol_local),
the method Field::send_binary() was renamed just to Field::send().

Note, this change introduces symmetry between Field and Item,
because Items also send themself using a single method Item::send(),
which is used for *all* protocol types.

Performance improvement is achieved by the fact that Protocol_text
implements these data type specific methods using store_numeric_string_aux()
rather than store_string_aux(). The conversion now happens only when
character_set_results is not ASCII compatible character sets
(e.g. UCS2, UTF16, UTF32).

In the old code (before any MDEV-23162 work, e.g. as of 10.5.4),
Protocol_text::store(Field*) used val_str() for all data types.
So the execution went through the character set conversion routines
even for numeric and temporal data types.

Benchmarking summary (see  details in MDEV-23478):

The new approach stably demonstrates additional improvement comparing
to the previous implementation (the smaller time - the better):

Original   - the commit before MDEV-23162
             be98036f

        1m9.336s
        1m9.290s
        1m9.300s

MDEV-23162 - the repertoire optimization

        1m6.101s
        1m5.988s
        1m6.264s

MDEV-23478 - this commit

        1m2.150s
        1m2.079s
        1m2.099s

This reverts commit eb2eaba7.

A different implementation of MDEV-23162 is coming.

As the first entry, define user 'ottok' (Otto Kekäläinen) as the person
who by default gets assigned all PRs that modify the debian/ contents.

Also, fix GCC -Og -Wmaybe-uninitialized in run_backup_stage()

Fix some more cases after merging
commit 31aef3ae.
Some warnings look possibly genuine, others are clearly bogus.

fil_page_decompress(): Remove a rather useless debug check.
We should have test coverage for reading page_compressed pages
from files, either due to buffer pool page eviction or due to
server restarts.

A similar check was removed from fil_space_encrypt() in
commit 0b36c27e (MDEV-20307).

There is no mysql_upgrade_wizard target, only mariadb-upgrade-wizard

The post-build custom command to embed Vista elevation manifest into
mariadb-upgrade-wizard.exe seems to do
something nasty to the executable, perhaps it removes and recreates it.

Thus the previously created hardlink mysql_upgrade_wizard is not marked
to require elevation.

Solved by using MANIFESTUAC linker flag, rather than invoke mt.exe.
This avoids an extra post-build step that modifies mariadb-upgrade-wizard.exe

The usage message for the innodb_compression_algorithm system variable
did not list snappy, which was added as an optional compression algorithm
in MariaDB 10.1.3 and might actually work since
commit 90c52e52 (MDEV-12615)
in MariaDB 10.1.24.

Unfortunately, we will include also unavailable compression algorithms
in the list, because ENUM parameters allow numeric values, and we do
not want innodb_compression_algorithm=3 to change meaning depending on
the way how the source code was compiled.

InnoDB only reserves 13 bits for the heap number in the record header,
limiting the heap number to be at most 8191. But, when using
innodb_page_size=64k and secondary index records of 7 bytes each,
it is possible to exceed the maximum heap number.

btr_cur_optimistic_insert(): Let the operation fail if the
maximum number of records would be exceeded.

page_mem_alloc_heap(): Move to the same compilation unit with the
only caller, and let the operation fail if the maximum heap number
has been allocated already.

The debug assertion is bogus, and we had removed it in
commit b1ab211d (MDEV-15053)
in the MariaDB Server 10.5 branch.

For a small data file, fil_space_extend_must_retry() would always
allocate a minimum size of 4*innodb_page_size.

It is possible that random read-ahead will be triggered for
a smaller file than this. In the observed case, the read-ahead
was triggered for a 6-page file that used ROW_FORMAT=COMPRESSED
with 8KiB page size. So, the desired file size was 49152 bytes,
but the actual size was 65536 bytes.

In 10.3, DBUG_ASSERT() may expand to something that includes
__builtin_expect(), which expects integer arguments, not pointers.
To avoid any compiler warnings, let us use an explicit rather than
implicit comparison to the null pointer.

innobase_pk_order_preserved(): Treat an added AUTO_INCREMENT
column in the same way as an added existing column.
In either case, the column values are not guaranteed to
be constant, and thus the ordering may change if such a column
is added before any existing PRIMARY KEY columns.

prepare_inplace_alter_table_dict(): Initialize
dict_table_t::persistent_autoinc before invoking
innobase_pk_order_preserved().

Patch 4aaa38d2 is replacing `my_config.h` with
`my_global.h` which is included in in-source build, but not for
out-of-source build tree.

Closes #1466

fil_system_t::keyrotate_next(): If space && space->is_in_rotation_list
does not hold, iterate from the start of the list.

In debug builds, we would typically have hit SIGSEGV because the
iterator would have wrapped a null pointer. It might also be that
we are dereferencing a stale pointer.

There is no test case, because the encryption is very nondeterministic
in nature, due to the use of background threads.

This scenario can be hit by setting the following:

SET GLOBAL innodb_encryption_threads=5;
SET GLOBAL innodb_encryption_rotate_key_age=0;

For some reason, GCC emits more -Wmaybe-uninitialized warnings
when using the flag -Og than when using -O2. Many of the warnings
look genuine.

The problem is caused by the fact that adding the
--defaults-group-suffix option to fix MDEV-18863 causes
mysqld to read all options from the appropriate sections
of the config file, including options specific to mysqld_multi.
Reading unknown options (which are not supported by mysqld)
causes mysqld to terminate with an error.

However, the MDEV-18863 problem has been completely fixed
by passing options on the command line, and now there is no
need to specify the --defaults-group-suffix option (we just
need to give priority to options passed through the command
line, so as not to break MDEV-18863).

IFNULL(inet6_not_null_expr, 'foo') erroneously set its nullability to NOT NULL.

Fix:
- Moving the line "maybe_null= args[1]->maybe_null" before the call
  of fix_length_and_dec2(), so the call of Type_handler method
  Item_hybrid_func_fix_attributes() can reset it when desired.

- Fixing Type_handler_inet6::Item_hybrid_func_fix_attributes()
  to ignore args[0] when detecting nullability of IFNULL().

In the merge eae968f6, it turns out that
I had accidentally initiated an in-source build in the past, and
$MYSQL_TZINFO_TO_SQL was pointing to a stale copy of the executable in
the source directory, instead of the correct one in the build directory.

During SST we need to let FTWRL to use normal timeout method
even when client is disconnected.

Some tests relied on the fact that DATETIME->DATE conversion
always produce a truncation (with a warning). This is not the case
when the SQL statement is executed at current time '00:00:00' sharp.

Adding a new SET TIMESTAMP statements to make sure time is not '00:00:00'.

Implement a workaround to shut the "memory not freed" message.