The only change is a change of the version number.
As noted in commit 02af6278
there were no changes to InnoDB between MySQL 5.6.46 and 5.6.47
either.

The function wsrep_on() was being called rather frequently
in InnoDB and XtraDB. Let us cache it in trx_t and invoke
trx_t::is_wsrep() instead.

innobase_trx_init(): Cache trx->wsrep = wsrep_on(thd).

ha_innobase::write_row(): Replace many repeated calls to current_thd,
and test the cheapest condition first.

fix embedded innodb_plugin tests

followup for 7198c6ab

Backport INSALL_SYMLINK cmake macro from 10.3.
It'll make libmysqlclient_r.* symlinks to link to the actual
shared library file, not to another symlink.

As a bonus it'll fix cmake warning about deprecated LOCATION property

This is a backport of the applicable part of
commit 93475aff and
commit 2c39f69d
from 10.4.

Before 10.4 and Galera 4, WSREP_ON is a macro that points to
a global Boolean variable, so it is not that expensive to
evaluate, but we will add an unlikely() hint around it.

WSREP_ON_NEW: Remove. This macro was introduced in
commit c863159c
when reverting WSREP_ON to its previous definition.

We replace some use of WSREP_ON with WSREP(thd), like it was done
in 93475aff. Note: the macro
WSREP() in 10.1 is equivalent to WSREP_NNULL() in 10.4.

Item_func_rand::seed_random(): Avoid invoking current_thd
when WSREP is not enabled.

_ma_fetch_keypage(): Correct an assertion that used to always hold.
Thanks to clang -Wint-in-bool-context for flagging this.

double_to_datetime_with_warn(): Suppress -Wimplicit-int-float-conversion
by adding a cast. LONGLONG_MAX converted to double will actually be
LONGLONG_MAX+1.

Since commit 7198c6ab
the ./mtr --embedded tests would fail to start innodb_plugin
because of an undefined reference to the symbol wsrep_log().

Let us define a stub for that function. The embedded server
is never built WITH_WSREP, but there are no separate storage
engine builds for the embedded server. Hence, by default,
the dynamic InnoDB storage engine plugin would be built WITH_WSREP
and it would fail to load into the embedded server library due to
a reference to the undefined symbol.

maria_page_crc_check_index(): Do not attempt to convert
HA_ERR_WRONG_CRC (176) to my_bool (char).
On platforms where char is signed, the 176 will be converted to -80.

It turns out that the callers only care whether the result is zero.
Let us return 1 in this case, like we do in all other error cases.

Several tests that involve stored procedures fail on 10.4 kvm-asan
(clang 10) due to stack overrun. The main contributor to this stack
overrun is mysql_execute_command(), which is invoked recursively
during stored procedure execution.

Rebuilding with cmake -DWITH_WSREP=OFF shrunk the stack frame size
of mysql_execute_command() by more than 10 kilobytes in a
WITH_ASAN=ON, CMAKE_BUILD_TYPE=Debug build. The culprit
turned out to be the macro WSREP_LOG, which is allocating a
separate 1KiB buffer for every occurrence.

We replace the macro with a function, so that the stack will be
allocated only when the function is actually invoked. In this way,
no stack space will be wasted by default (when WSREP and Galera
are disabled).

This backports commit b6c5657e
from MariaDB 10.3.1.

Without ASAN, compilers can be smarter and optimize the stack usage.
The original commit message mentions that 1KiB was saved on GCC 5.4,
and 4KiB on Mac OS X Lion, which presumably uses a clang-based compiler.

After MDEV-12353, the consistency check that I originally added for
commit 1b9fe0bb
(InnoDB Plugin for MySQL 5.1) started randomly failing.

It turns out that the IMPORT TABLESPACE code was always incorrect:
it did not update the (redundantly stored) tablespace ID
in index tree root pages. It only does that for page headers
and BLOB pointers.

PageConverter::update_index_page(): Update the tablespace ID
in the BTR_SEG_TOP and BTR_SEG_LEAF of index root pages.

This is a backport of commit b8b3edff.

For some reason, when mbstream is compiled with GCC 10,
ld will fail to link it due to a multiple definition of
datasink_buffer. The code appears to have been like that
since the very beginning.

Let us remove the duplicate dummy definition.

Windows GNU patch 2.7.6 is ok without it.

So account for the old buildbot version for now.

Linux works without it.

--binary fails on FreeBSD-12.0:

$ patch --version
patch 2.0-12u11 FreeBSD
$ patch --binary
patch: unrecognized option `--binary'

This reverts commit 1749a689.

The reason why we need --binary for patch is because of a bug in
patch.exe 2.5.9. We need to supply binary otherwise the patch program
crashes.

Tests will fail otherwise. Backport change from:
867809f2

Include CMAKE_C{XX,}_FLAGS=/W0 as 10k warnings
exist in 10.1 branch which cause the build to fail.

This causes problems on FreeBSD which doesn't have a patch
that supports this.

Linux and Windows don't require it either.

Was added in c3987707 without
explaination.

When index_merge_sort_union is turned off only ror scans were considered for range
scans, which is wrong.
To fix the problem ensure both ror scans and non ror scans are considered for range
access

When trying to start mariadb via systemctl, WSREP failed
to start mysqld for wsrep recovery, because the binary
"galera-recovery" is neither searching the mysqld in the
same folder as the binary itself nor in the path variable
but instead expects the root to be /usr/local/mysql.

This fix changes the current directory to the desired
directory before starting mysqld.

A new parameter has been added called xml-report, with which the
filename of the XML file is given to which the XML result is
written. There is also xml-package for adding a package value in
the XML output. Example usage:
./mysql-test-run.pl main.events_bugs innodb.count_distinct
main.explain_json innodb.file_format_defaults json.json_no_table
--suite=main,innodb,json --force --xml-report=build123456789.xml
--xml-package=simpletestrun

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

It took me a long time to debug why my configs were not being loaded,
and judging from online discussions I'm not the only one. Make the
comment in the default my.cnf a bit more helpful.

The !includedir directive is implemented in mysys/my_default.c.

- f_extensions[] is a list of file extensions. It includes .ini and .cnf
  on Windows, and only .cnf on all other platforms.
- search_default_file_with_ext() contains the !includedir directive. It
  filters files in the directory to those matching f_extensions[].

This file should only be applicable on Unix-like platforms, so only
files with the .cnf extension are read.

Closes #1485

Let us enable all GCC and clang warnings independently of the
MYSQL_MAINTAINER_MODE setting for both Debug and RelWithDebInfo
builds, and have MYSQL_MAINTAINER_MODE only enable -Werror.

The default setting of MYSQL_MAINTAINER_MODE=AUTO will continue
to apply the -Werror only to CMAKE_BUILD_TYPE=Debug. To build
a debug version without -Werror, MYSQL_MAINTAINER_MODE=OFF can
be used.

--ignore-table-data parameter added.

			FOREIGN_KEY_CHECKS is disabled

- dict_foreign_find_index() can return NULL if InnoDB already dropped
the foreign index when FOREIGN_KEY_CHECKS is disabled.

these three SHOW statements (and more) are issued from
include/analyze-sync_with_master.test too.
no need to do it twice.

The problem happened in these line:

uval0= (ulonglong) (val0_negative ? -val0 : val0);
uval1= (ulonglong) (val1_negative ? -val1 : val1);

return check_integer_overflow(val0_negative ? -(longlong) res : res,
                              !val0_negative);

when unary minus was performed on -9223372036854775808.
This behavior is undefined in C/C++.

This bug could manifest itself in a very rare cases when the optimizer
chose an execution plan by which a joined table was accessed by a table
scan and the optimizer was checking whether ranges checked for each record
could improve this plan. In such cases the optimizer evaluates range
conditions over a table that depend on other tables. For such conditions
the constructed SEL_ARG trees are marked as MAYBE_KEY. If a SEL_ARG object
constructed for a sargable condition marked as RANGE_KEY had the same
first key part as a MAYBE_KEY SEL_ARG object and the key_and() function
was called for this pair of SEL_ARG objects then an invalid SEL_ARG
object could be constructed that ultimately could lead to a crash before
the execution phase.

to work better for CPUs with more than 2000 bogomips.
old behavior is preserved if less than 2500 bogomips.

see e.g. `add_to_status()`

          'index_merge_sort_union=off'

When index_merge_sort_union is set to 'off' and  index_merge_union is set
to 'on' then any evaluated index merge scan must consist only of ROR scans.
The cheapest out of such index merges must be chosen. This index merge
might not be the cheapest index merge.

actually, page_zip_verify_checksum() generally allows all-zeroes
checksums because our CRC32 checksum is something like
crc_1 ^ crc_2 ^ crc_3

Also, all zeroes page is considered correct.

As a side effect fix nasty reinterpret_cast<> UB

Also, since c0f47a4a innodb_checksum_algorithm=full_crc32
exists which computes CRC32 in one go (without bitwise arithmetic)