In file sql/opt_range.cc,when calculate_cond_selectivity_for_table() is called with optimizer_use_condition_selectivity=4 then
	- thd->no_errors is set to 1
	- the original value of thd->no_error is not restored to its original value
	- this is causing the assertion to fail in the subsequent queries

Fixed by restoring the original value of thd->no_errors

     Tasks:-
         Changes in wsrep_dirty_reads variable
         1.) Global + Session scope (Current: session-only)
         2.) Can be set using command line.
         3.) Allow all commands that do not change data (besides SELECT)
         4.) Allow prepared Statements that do not change data
         5.) Works with wsrep_sync_wait enabled

This reverts commit 7ed5563b.

Reduce the number of calls to encryption_get_key_get_latest_version
when doing key rotation with two different methods:

(1) We need to fetch key information when tablespace not yet
have a encryption information, invalid keys are handled now
differently (see below). There was extra call to detect
if key_id is not found on key rotation.

(2) If key_id is not found from encryption plugin, do not
try fetching new key_version for it as it will fail anyway.
We store return value from encryption_get_key_get_latest_version
call and if it returns ENCRYPTION_KEY_VERSION_INVALID there
is no need to call it again.

After applying/replaying the transaction, the memory that
stored the query string was also wrongly freed.

... causes MariaDB to crash

On error, the wsrep replication buffer (binlog) is dumped to a file
to aid investigations. In order to also include the binlog header,
FDLE object is also needed. This object is only available for wsrep-
threads.
Fix: Instantiate an FDLE object for non-wsrep threads.

Add 'which' to REQUIRES list.

Role names with trailing whitespaces are truncated in length as of
956e92d9 to fix MDEV-8609. The problem
is that the code that creates role mappings expects the string to be null
terminated.

Add the null terminator to account for that as well. In the future
the rest of the code can be cleaned up to never assume c style strings
but only LEX_STRINGS.

        Functions from sql/statistics.cc don't seem to expect
        stat tables to fail or to have inadequate structure.
        Table open errors suppressed and some validity
        checks added. Invalid tables reported to the server
        log.

MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))

Different fix. Don't allow Item_func_sp to be evaluated unless
all tables are prelocked.

Extend the test case to make sure Item_func_sp::val_str is called
(the table must have at least one row for that).

Revert "MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))"

This reverts commit 035a5ac6.

Two minor problems and one regression:
1. caching the value in str_result. Other Item methods may use it,
   destroying the cache. See, for example, Item::save_in_field, where
   str_result is moved to use a local buffer (this failed main.grant)
2. Item_func_conv_charset::safe is now set too late, it's initialized
   only in val_str() but checked before that, this failed many tests
   in optimized builds.

to fix 1 - use tmp_result instead of str_result, to fix 2, use
the else branch in the Item_func_conv_charset constructor to set
safe purely from charset properties.

But this introduces a regression, constant strings can no longer be
converted, say, from utf8 to latin1 (because 'safe' will be false).
This fails few tests too. There is no way to fix it without reverting
the commit and converting constants, as before, in the constructor.

The race condition happened if mark_xid_done was considerably delayed,
and an extra Binlog_checkpoint event was written into the binary log
which was later indicated in an error message. Fixed by ensuring
that the event is written before the binary log is rotated to the one
which is used in the output.

The reason is a simple race condition. Initially the test was meant to synchronize with master
before showing tables, but it turned out that the slave IO thread should fail by this point,
and synchronization was removed along with a server bugfix. Now added an intermediate sync
instead, to make sure that slave has replicated events before the point of failure

MDEV-11162 Assertion `num_records == m_idx_array.size()' failed in Filesort_buffer::alloc_sort_buffer(uint, uint)

Updating result for the group_by_innodb.test

MDEV-11162 Assertion `num_records == m_idx_array.size()' failed in Filesort_buffer::alloc_sort_buffer(uint, uint)

When JOIN::destroy() is called for a JOIN object that has
   - join->tmp_join != NULL
   - also has join->table[0]->sort

then the latter was not cleaned up.
This could cause a memory leak and/or asserts in the subsequent queries.

Fixed by adding a cleanup call.

truncate unused IO_CACHE backing store files in binlog_cache_data
to release the disk space they were occupying

        Rpl_filter::parse_filter_rule() made NULL-safe.

Update mysqld_multi man page

fixes MDEV-11354 twin include

Update mysqldump man page

check for VIEW/DERIVED fields

MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))

Move expression execution out of Item constructor.

Exclude untouched in prepare phese subqueries from the select/unit tree
because they became unreachable by execution.

when crashing on a signal, don't exit(), but re-signal it, so that
the caller could check WIFSIGNALED()

mysqld_safe: don't close stdout and stderr if --dry-run

support encrypted binlogs. Not decryption, but at least recognizing
that event are encrypted and prining them as such

MDEV-11288 Server crashes in Binlog_crypt_data::init trying to feed encrypted log without decryption capabilities

The problem was that null_value was not set to "false" on a well-formed row.
If an ill-formed row was followed by a well-forned row, null_value remained
"true" in the call of Item::send() for the well-formed row.

- created binlog_encryption test suite and added it to the default list
- moved some tests from rpl, binlog and multisource suites to extra
  so that they could be re-used in different suites
- made minor changes in include files

Check for readline before checking for curses headers, because
MYSQL_CHECK_READLINE fails when curses is not found, but
CHECK_INCLUDE_FILES simply remembers the fact and continues.  So if
there's no curses, MYSQL_CHECK_READLINE will abort, the user will then
installs curses and continue the build. Thus, CHECK_INCLUDE_HEADERS
will remember that there is no curses, but other checks from
MYSQL_CHECK_READLINE will remember that curses are there. It will
result in inconsistent HAVE_xxx defines.

crashes server

This bug is the result of merging the Oracle MySQL follow-up fix
BUG#22963169 MYSQL CRASHES ON CREATE FULLTEXT INDEX
without merging the base bug fix:
Bug#79475 Insert a token of 84 4-bytes chars into fts index causes
server crash.

Unlike the above mentioned fixes in MySQL, our fix will not change
the storage format of fulltext indexes in InnoDB or XtraDB
when a character encoding with mbmaxlen=2 or mbmaxlen=3
and the length of a word is between 128 and 84*mbmaxlen bytes.
The Oracle fix would allocate 2 length bytes for these cases.

Compatibility with other MySQL and MariaDB releases is ensured by
persisting the used maximum length in the SYS_COLUMNS table in the
InnoDB data dictionary.

This fix also removes some unnecessary strcmp() calls when checking
for the legacy default collation my_charset_latin1
(my_charset_latin1.name=="latin1_swedish_ci").

fts_create_one_index_table(): Store the actual length in bytes.
This metadata will be written to the SYS_COLUMNS table.

fts_zip_initialize(): Initialize only the first byte of the buffer.
Actually the code should not even care about this first byte, because
the length is set as 0.

FTX_MAX_WORD_LEN: Define as HA_FT_MAXCHARLEN * 4 aka 336 bytes,
not as 254 bytes.

row_merge_create_fts_sort_index(): Set the actual maximum length of the
column in bytes, similar to fts_create_one_index_table().

row_merge_fts_doc_tokenize(): Remove the redundant parameter word_dtype.
Use the actual maximum length of the column. Calculate the extra_size
in the same way as row_merge_buf_encode() does.