Remove plugin functions via item_create_remove() at deinit time.

Item_func_history (is_history()) is a bool function that checks if the
row is the history row by checking row_end->is_max(). The argument to
this function must be row_end system field.

Added the above function to conjunction with SYSTEM_TIME_BEFORE
versioning condition.

row_merge_is_index_usable(): Allow access to any SEQUENCE, even if it was
created after the read view. SQL sequences are no-rollback tables with no
history at all.

Quoting MDEV reporter Daniel Lewart:

Starting MariaDB with default configuration causes the following problems:

    "[Warning] Could not increase number of max_open_files to more than 16384 (request: 32186)"
    silently reduces table_open_cache_instances from 8 (default) to 4

Default Server System Variables:

    extra_max_connections = 1
    max_connections = 151
    table_open_cache = 2000
    table_open_cache_instances = 8
    thread_pool_size = 4

LimitNOFILE=16834 is in the following files:

    support-files/mariadb.service.in
    support-files/mariadb@.service.in

Looking at sql/mysqld.cc lines 3837-3917:
wanted_files= (extra_files + max_connections + extra_max_connections +
tc_size * 2 * tc_instances);
wanted_files+= threadpool_size;

Plugging in the default values:
wanted_files = (30 + 151 + 1 + 2000 * 2 * 8 + 4) = 32186

However, systemd configuration has LimitNOFILE = 16384, which is far smaller.

I suggest increasing LimitNOFILE to 32768.

This is a backport of
commit fd9ca2a7 (MDEV-23295) and
commit 9a156e1a (MDEV-23345) to 10.3.

An instant ADD/DROP/reorder column could create a dummy table
object with the wrong ROW_FORMAT when innodb_default_row_format
was changed between CREATE TABLE and ALTER TABLE.

prepare_inplace_alter_table_dict(): If we had promised that
ALGORITHM=INPLACE is supported, we must preserve the ROW_FORMAT.

The rest of the changes are related to adding
Alter_inplace_info::inplace_supported to cache the return value of
handler::check_if_supported_inplace_alter().

Back port upstream fix

commit 1800b015a1d487330f7b15f2020b887be348a66b
Author: Venkatesh Duggirala <venkatesh.duggirala@oracle.com>
Date:   Fri Sep 8 20:29:22 2017 +0530

Bug#26027024    SLAVE_COMPRESSED_PROTOCOL DOESN'T WORK WITH
SEMI-SYNC REPLICATION IN MYSQL-5.7

Analysis: In mysql-5.6, dump thread (the thread that is created
on Master after Slave requested for a binlog dump) is also used
to receive acknowledgements from the Slave and act on them accordingly.
For performance reasons, a special thread called Ack Receiver thread
is added in mysql-5.7 Semi synchronous replication plugin.
This thread does not have special handling to receive acknowledgements
if Slave has enabled compression in the protocol. Hence Master is
unable to handle any slave if Slave_compressed_protocol is enabled
on it.

Fix: Enable compress flag on the communication channels if the Slave
has Slave_compressed_protocol ON.

(trivial backport to 10.2)
Add a testcase

(trivial backport to 10.2)
The optimizer removes redundant GROUP BY operations. If GROUP BY element
is a subselect, it is "eliminated".

However one must not eliminate the item if it is used both in the select
list and in the GROUP BY, like so:

  select (select ... ) as SUBQ from ... group by SUBQ

Do not eliminate such items.

Add a testcase

The optimizer removes redundant GROUP BY operations. If GROUP BY element
is a subselect, it is "eliminated".

However one must not eliminate the item if it is used both in the select
list and in the GROUP BY, like so:

  select (select ... ) as SUBQ from ... group by SUBQ

Do not eliminate such items.

complemented the fix for MDEV-24823 in 10.2. As it is the only call of
this function in 10.3 the commit also has added the code of the function.

except commit 1288dfff

It is possible that an object that was originally created by
open_purge_table() will remain cached and reused for SQL execution.
Our previous fix wrongly assumed that ha_innobase::open() would
always be called before SQL execution starts. Therefore, we must
invoke dict_stats_init() in ha_innobase::info_low() instead of
only doing it in ha_innobase::open().

Note: Concurrent execution of dict_stats_init() on the same table
is possible, but it also was possible between two calls to
ha_innobase::open(), with no ill effects observed.

This should fix the assertion failure on stat_initialized.
A possibly easy way to reproduce it would have been
to run the server with innodb_force_recovery=2 (disable the purge of
history), update a table so that an indexed virtual column will be
affected, and finally restart the server normally (purge enabled),
to observe a crash when the table is accessed from SQL.

The problem was first observed and this fix verified by
Elena Stepanova. Also Thirunarayanan Balathandayuthapani
repeated the problem.

row_sel_sec_rec_is_for_clust_rec(): If the field in the
clustered index record stored off page, always fetch it,
also when the secondary index field has been built on the
entire column. This was broken ever since the InnoDB Plugin
for MySQL Server 5.1 introduced ROW_FORMAT=DYNAMIC and
ROW_FORMAT=COMPRESSED for InnoDB tables. That code was first
introduced in this tree in
commit 3945d5e5.

For the original ROW_FORMAT=REDUNDANT and the MySQL 5.0.3
ROW_FORMAT=COMPRESSED, there was no problem, because for
those tables we always stored at least a 768-byte prefix of
each column in the clustered index record.

row_sel_sec_rec_is_for_blob(): Allow prefix_len==0 for matching
the full column.

Before FRM is written walk vcol expressions through
check_table_name_processor() and check if field items match (db,
table_name) qualifier.

We cannot do this in check_vcol_func_processor() as there is already
no table name qualifiers in expressions of written and loaded FRM.

Buffer overflow in ib_push_warning() fixed by using vsnprintf().

InnoDB parser was obsoleted by MDEV-16417.

Thanks to Nikita Malyavin for review and suggestion.

It's Oracle libmysqlclient license exception, we no longer include,
build or ship libmysqlclient

Before this patch mergeable derived tables / view used in a multi-table
update / delete were merged before the preparation stage.
When the merge of a derived table / view is performed the on expression
attached to it is fixed and ANDed with the where condition of the select S
containing this derived table / view. It happens after the specification of
the derived table / view has been merged into S. If the ON expression refers
to a non existing field an error is reported and some other mergeable derived
tables / views remain unmerged. It's not a problem if the multi-table
update / delete statement is standalone. Yet if it is used in a stored
procedure the select with incompletely merged derived tables / views may
cause a problem for the second call of the procedure. This does not happen
for select queries using derived tables / views, because in this case their
specifications are merged after the preparation stage at which all ON
expressions are fixed.
This patch makes sure that merging of the derived tables / views used in a
multi-table update / delete statement is performed after the preparation
stage.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

Before this patch mergeable derived tables / view used in a multi-table
update / delete were merged before the preparation stage.
When the merge of a derived table / view is performed the on expression
attached to it is fixed and ANDed with the where condition of the select S
containing this derived table / view. It happens after the specification of
the derived table / view has been merged into S. If the ON expression refers
to a non existing field an error is reported and some other mergeable derived
tables / views remain unmerged. It's not a problem if the multi-table
update / delete statement is standalone. Yet if it is used in a stored
procedure the select with incompletely merged derived tables / views may
cause a problem for the second call of the procedure. This does not happen
for select queries using derived tables / views, because in this case their
specifications are merged after the preparation stage at which all ON
expressions are fixed.
This patch makes sure that merging of the derived tables / views used in a
multi-table update / delete statement is performed after the preparation
stage.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

Fix is to changed message to be [WARNING] for backup

There is new Yukon Standard time Windows timezone.

Also fix the powershell script that generates the Windows locale mapping,
tell powershell to use TLSv1.2 to access the github (on some reason it is
TLS1.1 that powershell is using by default, and it does no work)

		to mysql interpreter

InnoDB returns uninitialized statistics to mysql interpreter
when background thread is opening the table. So it leads to
assertion failure. In that case, InnoDB avoid sending
innodb statistics information to mysql interpreter.

node->index was NULL.
But it's possible to get dict_table_t* from another source.

There was race between a committing transaction and the following in binlog
order FLUSH LOGS that could create a 2nd Binlog checkpoint (BCP) event
in the new file *before* the first logged-in-old-binlog transaction gets committed in
Innodb. That would cause the transaction loss at recovery, should
the server stop right after the BCP.

The race is tackled by enforcing the necessary set of mutexes to be acquired
by FLUSH-LOGS handler in the correct order (of the group commit leader
pattern).

Note, there remain two cases where a similar race is still possible:
  - the above race as it is when the server is run with ("unlikely")
    non-default `--binlog-optimize-thread-scheduling=0` (MDEV-24530), and
  - at unlikely event of bin-logging of Incident event (MDEV-24531) that
    also triggers binlog rotation,
    in both cases though with lesser chances after the current fixes.

Closes #1811

Since it ended up being a plain text file rather than a script
(post-fix for MDEV-25288)
Also removed main-test_sql_discovery.create from the list,
as a workaround for MDEV-25384. The bug only affects 10.3+,
but it will be simpler if 10.2 part of the tests is the same
in all branches

... to run upon building/packaging of MariaDB server

Eliminate a memory leak when init can fail by forgetting to delete the
Event_queue_element_for_exec object.

PROBLEM
-------

1. The customer had presented a stack which had many threads waiting on
   multiple mutexes like LOCK_Status, srv_innodb_monitor_mutex,  ibuf_mutex etc.
2. The root cause was that the AHI latch was held in S (shared) mode by the a thread which was
   doing a truncate of a large table .
3. There was another thread which was trying to acquire the AHI latch in X (exclusive) mode
4. With our lock implementation any thread requesting a X lock ,blocks rest of the threads
   requesting S(shared) locks,this caused many threads to wait for this shared lock.
5. The main reason why we hold the latches in truncate is to avoid disabling of AHI
   during truncate

FIX

When dropped all user key-parts we also drop key-parts of implicit system fields.

This patch sets the proper name resolution context for outer references
used in a subquery from an ON clause. Usually this context is more narrow
than the name resolution context of the parent select that were used before
this fix.
This fix revealed another problem that concerned ON expressions used in
from clauses of specifications of derived tables / views / CTEs. The name
resolution outer context for such ON expression must be set to NULL to
prevent name resolution beyond the derived table where it is used.
The solution to resolve this problem applied in sql_derived.cc was provided
by Sergei Petrunia <sergey@mariadb.com>.

The change in sql_parse.cc is not good for 10.4+. A corresponding diff for
10.4+ will be provided in JIRA entry for this bug.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

It seems some overly tolerant compilers (gcc) allow the structure
of IO_CACHE that is defined differently in libmaria to have
members equalivance to the iocache in mysys.

More strict Solaris compilers recognise that rc_pos really
isn't a structure member and won't compile.

Make Item_subselect::walk() walk the ON expressions, too.