trx_purge_add_update_undo_to_history(): Relax the too strict assertion
by removing the condition on srv_fast_shutdown (innodb_fast_shutdown).
Rollback is allowed during any form of shutdown.

buf_dump(): Only generate the output when shutdown is in progress.

log_write_up_to(): Only generate the output before actually writing
to the redo log files.

srv_purge_should_exit(): Rate-limit the output, and instead of
displaying the work done, indicate the work that remains to be done
until the completion of the slow shutdown.

Item_subselect::is_expensive() used to return FALSE (Inexpensive) whenever
it saw that one of SELECTs in the Subquery's UNION is degenerate. It
ignored the fact that other parts of the UNION might not be inexpensive,
including the case where pther parts of the UNION have no query plan yet.

For a subquery in form col >= ANY (SELECT 'foo' UNION SELECT 'bar')
this would cause the query to be considered inexpensive when there is
no query plan for the second part of the UNION, which in turn would
cause the SELECT 'foo' to compute and free itself while still inside
JOIN::optimize for that SELECT (See MDEV comment for full description).

MDEV-15475: Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' failed on EXPLAIN EXTENDED with constant table and view

Print constant ISNULL value independent.
Fix of printing of view FRM and CREATE VIEW output

If we have a 2+ node cluster which is replicating from an async master
and the binlog_format is set to STATEMENT and multi-row inserts are executed
on a table with an auto_increment column such that values are automatically
generated by MySQL, then the server node generates wrong auto_increment
values, which are different from what was generated on the async master.

The causes and fixes:

1. We need to improve processing of changing the auto-increment values
after changing the cluster size.

2. If wsrep auto_increment_control switched on during operation of
the node, then we should immediately update the auto_increment_increment
and auto_increment_offset global variables, without waiting of the next
invocation of the wsrep_view_handler_cb() callback. In the current version
these variables retain its initial values if wsrep_auto_increment_control
is switched on during operation of the node, which leads to inconsistent
results on the different nodes in some scenarios.

3. If wsrep auto_increment_control switched off during operation of the node,
then we must return the original values of the auto_increment_increment and
auto_increment_offset global variables, as the user has set. To make this
possible, we need to add a "shadow copies" of these variables (which stores
the latest values set by the user).

MDEV-15933 Cannot resume Node SYNCED state when wsrep_desync is done after FTWRL

Moved parts of mysql.test to mysql_not_windows.test

Manually setting wsrep_desync after FTWRL should not be allowed.

Use real DACL instead of NULL DACL.
Grant Everyone just read/write access to pipe
(instead of all access like previously with NULL ACL)

truncate incorrect values in convert_period_to_month() so that
PERIOD_DIFF never returns a value outside of 2^23 range.

And, for safety, increase buffer sizes for int10_to_str
to be sufficienly big for any int10_to_str result.

* Backport from 10.4 to resolve dependency problem

Using the dependency syntax from 10.4 branch because {$LIBSSL} can not
be used.

not empty

We should swap the list only when list is not empty.

InnoDB executed code that is mean to execute only when Galera
is used and in bad luck one of the transactions is selected
incorrectly as deadlock victim. Fixed by adding wsrep_on_trx()
condition before entering actual Galera transaction handling.

No always repeatable test case for this issue is known.

After the commit b76b69cd
loose index scan for queries with DISTINCT stopped working.
That is why that commit has to be reverted.
Additionally this patch  fixes the problem of MDEV-10880.

MDEV-15511 - Use stunnel during rsync SST if available

Use table_arg that was passed to the function, instead of dereferencing
this->table, which is a NULL pointer.

with spatial index

So the issue is since it is spatial index , at the time of searching index
for key (Rows_log_event::find_row) we use wrong field image we use
Field::itRAW while we should be using Field::itMBR

fts_query(): Remove a redundant condition (result will never be NULL),
and instead check if *result is NULL, to prevent SIGSEGV in
fts_query_free_result().

The functions fts_ast_visit() and fts_query() inside
InnoDB FULLTEXT INDEX query processing are not checking
for THD::killed (trx_is_interrupted()), like anything
that potentially takes a long time should do.

This is a port of the following change from MySQL 5.7.23,
with a completely rewritten test case.

commit c58c6f8f66ddd0357ecd0c99646aa6bf1dae49c8
Author: Aakanksha Verma <aakanksha.verma@oracle.com>
Date:   Fri May 4 15:53:13 2018 +0530

Bug #27155294 MAX_EXECUTION_TIME NOT INTERUPTED WITH FULLTEXT SEARCH USING MECAB

This is a backport of the following fix from MySQL 5.7.23.
Some code refactoring has been omitted, and the test case has
been adapted to MariaDB.

commit 7a689acaa65e9d602575f7aa53fe36a64a07460f
Author: Krzysztof Kapuścik <krzysztof.kapuscik@oracle.com>
Date:   Tue Mar 13 12:34:03 2018 +0100

Bug#27082268 Invalid FTS sync synchronization

The fix closes two issues:
Bug #27082268 - INNODB: FAILING ASSERTION: SYM_NODE->TABLE != NULL DURING FTS SYNC
Bug #27095935 - DEADLOCK BETWEEN FTS_DROP_INDEX AND FTS_OPTIMIZE_SYNC_TABLE

Both issues were related to a FTS cache sync being done during
operations that perfomed DDL actions on internal FTS tables
(ALTER TABLE, TRUNCATE). In some cases the FTS tables and/or
internal cache structures could get removed while still being
used to perform FTS synchronization leading to crashes. In other
the sync operations could not get finishes as it was waiting for
dict lock which was taken by thread waiting for the background
sync to be finished.

The changes done includes:
- Stopping background operations during ALTER TABLE and TRUNCATE.
- Removal of unused code in FTS.
- Cleanup of FTS sync related code to make it more readable and
easier to maintain.

RB#18262

We did not merge Percona XtraDB 5.6.40-84.0 yet.
The changes in it are mostly cosmetic, except for
2 bug fixes from Oracle MySQL 5.6.40, which could
be security bugs.

This was achieved by taking the applicable parts
of an earlier InnoDB commit to XtraDB:

git diff 15ec8c2f{~,} storage/innobase|
sed -e s+/innobase/+/xtradb/+|patch -p1