row_ins_cascade_calc_update_vec(): Remove the output parameter
fts_col_affected, and instead return whether any fulltext index
is affected by the cascade operation.

row_ins_foreign_check_on_constraint(): Narrow the scope of some
variables.

ib_dec_in_dtor: Remove.

If setting user variable was used in the specification of a recursive CTE
then Item_func_set_user_var::fix_fields() went into an infinite loop.

                 does not return error

Corrected the code of st_select_lex::find_table_def_in_with_clauses() for
a proper identification of CTE references used in embedded CTEs.

When identifying a table name the following should be taken into account:
a CTE name cannot be qualified with a database name, otherwise the table
name is considered as the name of a non-CTE table.

replace with awk (yuck!), avoiding gensub (which wasn't recognized)

all mmap-related functions take size_t lengh.
mmaped_length was casted to size_t *every single time*

conversion from 'my_off_t' to '::size_t', possible loss of data

get_rec_bits() must return uchar, it's result is often
assigned to uchar. And len is always less than 8.

this fixes the crash of main.fulltest

because dbug_print_item() can be invoked any time in gdb,
also before fix_fields.

this fixes a crash of main.win in debug builds

it was set before big if() that could decide not to merge and
go with materialization.

this fixes a crash in main.view test

in gcc `-Wno-unsupported-something` will not be an error or even a warning,
so cmake will think the flag is supported. But if there's any other
warning during compilation, for any reason, unknown option will
be a warning too. Or an error when -Werror, even if that "other warning"
would not be an error on itself.

So we need to detect whether `-Wno-unsupported-something` is *really*
supported. Luckily, `-Wunsupported-something` will always fail with an
error.

So, whenever there's a need to detect if -Wno-something is supported,
test -Wsomething instead.

Problem was that wrong error message was returned when insert
returned FK-error and there was no duplicate key to process.

row_ins
	If error from insert was DB_NO_REFERENCED_ROW and there was
	no duplicate key we should ignore ON DUPLICATE KEY UPDATE
	and return original error message.

Suppress some messages that are emitted rarely
(when the FIL_PAGE_FILE_FLUSH_LSN of the first page of ibdata1
does not match the latest redo log checkpoint).

Previously, the function could theoretically return an uninitialized
value if the system tablespace contained no data files. It should be
impossible for InnoDB to start up in such scenario.

xtrabackup_init_temp_log(): Remove a redundant variable and limit scope.

Two follow-up tasks were filed for MySQL 5.7.21 changes that
were not applied here:

MDEV-15179 performance_schema.file_instances does not reflect RENAME TABLE
MDEV-14222 Unnecessary 'cascade' memory allocation for every updated
row when there is no FOREIGN KEY

The merge omitted some InnoDB and XtraDB conflict resolutions,
most notably, failing to merge the fix of MDEV-12173.

ibuf_merge_or_delete_for_page(), lock_rec_block_validate():
Invoke fil_space_acquire_silent() instead of fil_space_acquire().
This fixes MDEV-12173.

wsrep_debug, wsrep_trx_is_aborting(): Removed unused declarations.

_fil_io(): Remove. Instead, declare default parameters for the XtraDB
fil_io().

buf_read_page_low(): Declare default parameters, and clean up some
callers.

os_aio(): Correct the macro that is defined when !UNIV_PFS_IO.

row_rename_partitions_for_mysql(): Remove. This should only be relevant
in an upgrade into MySQL 5.7, which has InnoDB native partitioning.

Remove a test that does not apply to MariaDB

In MariaDB, there are no high-priority transactions (no tx_priority).
This should also mean that all references to TRX_STATE_FORCED_ROLLBACK
are dead code.

Reviewed-by: Sunny Bains <sunny.bains@oracle.com>

Bug#23590280 NO WARNING WHEN REDUCING INNODB_BUFFER_POOL_SIZE
INSIZE (sic) THE FIRST CHUNK

innodb_buffer_pool_size_validate(): Issue a warning if the
requested innodb_buffer_pool_size is less than
innodb_buffer_pool_chunk_size, because we cannot shrink individual
chunks.

Import and adjust the innodb.innodb_buffer_pool_resize tests,
except innodb.innodb_buffer_pool_resize_debug, which would time out.

buf_pool_clear_hash_index(): Adjust assertions.

* use a longer timeout, 10ms is not always enough
* stop waiting as long as the data is read, do not unconditionally
  wait for timeout every time

mysqltest cannot free all memory on exit by design,
so there's no need to check.

mysql frees memory in mysql_end(), so enable memory-leak-on-exit check
only after it was initialized enough to use  mysql_end() - early exits
use my_end().

If binary logging is not enabled thd->user_var_events_alloc
would never be initialized.

The algorithm change is based on a MySQL 8.0 fix for
BUG #26818787: ASSERTION: DATA0DATA.IC:430:TUPLE
by Krzysztof Kapuścik
https://github.com/mysql/mysql-server/commit/ee606e62bbddd7ac3579b4a20ef8684fa7cd83fe

If a record had been inserted in place of a delete-marked purgeable
record by modifying that record, and purge was accessing that record
before the off-page columns were written, row_build_index_entry()
would have returned NULL, causing a crash.

row_vers_non_virtual_fields_equal(): Check whether all non-virtual fields
of an index are equal. Replaces row_vers_non_vc_match(). A more complex
version of this function was called row_vers_non_vc_index_entry_match()
in the MySQL 8.0 fix.

row_vers_impl_x_locked_low(): This change is not directly related to
the reported problem, but apparently to the removal of the function
row_vers_non_vc_match(). This function checks if a secondary index
record was modified by a transaction that has not been committed yet.
For comparing the non-virtual columns, construct a secondary index
tuple from the table row.

row_vers_vc_matches_cluster(): Replace row_vers_non_vc_match() with
code that is equivalent to the row_vers_non_vc_index_entry_match()
in the MySQL 8.0 fix. Also, deduplicate some code by using goto.