EINVAL means that the filesystem doesn't support posix_fallocate().

There were two places where this error was issued, one checked for
EINVAL, the other did not. This commit fixed the other place
to also check for EINVAL.

Also, remove the space after the REFMAN to get the valid url
with no space in the middle.

Also don't say "Make sure the file system supports this function."
when posix_fallocate() fails, because this message is only shown
when the filesystem does support this function.

fix Item_default_value not to pretend being const_item
if the field's default_value expression isn't parsed yet

MDEV-11750 Assertion `vfield' failed in TABLE::update_virtual_fields after crash recovery on corrupted MyISAM table

Adjust the length of the BIT field
(same as in _mi_put_key_in_record())

move TABLE::key_read into handler. Because in index merge and DS-MRR
there can be many handlers per table, and some of them use
key read while others don't. "keyread" is really per handler,
not per TABLE property.

MDEV-11784 View is created with invalid definition which causes ERROR 1241 (21000): Operand should contain 1 column(s)

set the correct print precedence for IN subqueries

Item_default_value::calculate was updating table->s->default_values,
but it is supposed to be read-only

Optionally do table->update_default_fields() even for INSERT
that supposedly provides values for all column. Because these
"values" might be DEFAULT, which would need table->update_default_fields()
at the end.

Also set Item_default_value::used_tables() from the default expression.
Non-zero used_field() means that mysql_insert() will initialize all
fields to their default values (with restore_record()) even if
all columns are later provided with values. Because default expressions
may refer to other columns and they must be initialized.

Remove also the field trx_t::read_write that was only used by
the Memcached hooks.

Oracle introduced a Memcached plugin interface to the InnoDB
storage engine in MySQL 5.6. That interface is essentially a
fork of Memcached development snapshot 1.6.0-beta1 of an old
development branch 'engine-pu'.

To my knowledge, there have not been any updates to the Memcached code
between MySQL 5.6 and 5.7; only bug fixes and extensions related to
the Oracle modifications.

The Memcached plugin is not part of the MariaDB Server. Therefore it
does not make sense to include the InnoDB interfaces for the Memcached
plugin, or to have any related configuration parameters:

    innodb_api_bk_commit_interval
    innodb_api_disable_rowlock
    innodb_api_enable_binlog
    innodb_api_enable_mdl
    innodb_api_trx_level

Removing this code in one commit makes it possible to easily restore
it, in case it turns out to be needed later.

log_crypt_101_read_checkpoint(): Read the encryption information
from a MariaDB 10.1 checkpoint page.

log_crypt_101_read_block(): Attempt to decrypt a MariaDB 10.1
redo log page.

recv_log_format_0_recover(): Only attempt decryption on checksum
mismatch. NOTE: With the MariaDB 10.1 innodb_encrypt_log format,
we can actually determine from the cleartext portion of the redo log
whether the redo log is empty. We do not really have to decrypt the
redo log here, if we did not want to determine if the checksum is valid.

We can use log_sys->buf instead of recv_sys->last_block during
crash recovery. Remove the redundant buffer.

innodb_shutdown(), trx_sys_close(): Startup may be aborted between
purge_sys and trx_sys creation. Therefore, purge_sys must be freed
independently of trx_sys.

innobase_start_or_create_for_mysql(): Remember to free purge_queue if
it was not yet attached to purge_sys.

These are different bugs, but the fixing code is the same:
if window functions are used over implicit grouping then
now the execution should follow the general path calling
the function set in JOIN::first_select.

Corrected an assertion in JOIN::create_postjoin_aggr_table():
JOIN::join_tab[0] can be the first aggregation table if
the query uses window functions.

main thread may destroy mutexes that bootstrap is using in
THD destructor.

Print the message as a note instead of warning.

New default sql_mode includes:
* STRICT_TRANS_TABLES
* ERROR_FOR_DIVISION_BY_ZERO
* NO_ENGINE_SUBSTITUTION
* NO_AUTO_CREATE_USER

The supplied sql_mode(s) should be converted to ASCII first,
before comparing it with the sql_mode set.

innodb_autoinc_lock_mode            = 2
innodb_buffer_pool_dump_at_shutdown = ON
innodb_buffer_pool_dump_pct         = 25
innodb_buffer_pool_load_at_startup  = ON
innodb_checksum_algorithm           = CRC32
innodb_file_format                  = Barracuda
innodb_large_prefix                 = ON
innodb_log_compressed_pages         = ON
innodb_purge_threads                = 4
innodb_strict_mode                  = ON
binlog_annotate_row_events          = ON
binlog_format                       = MIXED
binlog-row-event-max-size           = 8192
group_concat_max_len                = 1M
lock_wait_timeout                   = 86400
log_slow_admin_statements           = ON
log_slow_slave_statements           = ON
log_warnings                        = 2
max_allowed_packet                  = 16M
replicate_annotate_row_events       = ON
slave_net_timeout                   = 60
sync_binlog                         = 1
aria_recover                        = BACKUP,QUICK
myisam_recover_options              = BACKUP,QUICK

MDEV-10554: Assertion `!derived->first_select()->exclude_from_table_unique_test || derived->outer_select()-> exclude_from_table_unique_test' failed in TABLE_LIST::set_check_merged()

Mark and check excluded because of merging derived tables and views.

Due to this bug many queries that contained a window function
with MIN/MAX aggregation returned wrong results.

Calculation of a MIN/MAX aggregate function uses cache objects
and a comparator object that are created and set up in
Item_sum_hybrid::fix_fields () by a call of Item_sum_hybrid::setup_hybrid().
The latter binds the objects to the first argument of the
MIN/MAX function. Meanwhile window function perform aggregation
over fields of a temporary table. So binding must be done rather to
these fields. The earliest moment when setup the objects used in
MIN/max functions can be done is after all calls of the method
split_sum_func().

This patch introduces this late setup, but only for aggregate
functions used in window functions.
Probably it makes sense to use this late setup for all MIN/MAX
objects.

        Test fixed.

        Fix json_merge implementation.

        Test result updated.

This is follow-up to commit 1293e5e5.