it was generating broken spec files

eliminate_item_equal() uses quick_fix_field() for Item objects it creates.
It computes some of their attributes on its own (see update_used_tables()
call) but it doesn't update not_null_tables_cache.

Recompute not_null_tables_cache also. Not computing it is currently
harmless, except for producing MSAN error when some other code
propagates the wrong value of not_null_tables_cache to other item.

cmake bug #14362

- Suppress the "Difficult to find free blocks" warning
globally to avoid many different test case failing.

- Demote the error information in validate_first_page() to note.
So first page can recovered from doublewrite buffer and can throw
error in case the page wasn't found in doublewrite buffer.

to iterate over all status variables one should use
LOCK_all_status_vars not LOCK_status

this fixes sporadic mutex lock inversion in plugins.password_reuse_check:
* acl_cache->lock is taken over complex operations that might increment
  status counters (under LOCK_status).
* acl_cache->lock is needed to get the values of Acl% status variables
  when iterating over status variables

it broke tests on Windows. Use SEARCH_ABORT instead.
also, remove redundant features and simplify

when changing charset from latin1 to utf8, adjust max_length accordingly

Follow-up to fix comiler warings caused by present of
the clause override in declaration of the method Item_param::cleanup

MDEV-33622 Server crashes when the UPDATE statement (which has duplicate key) is run after setting a low thread_stack

This was caused by wrong allocation of variable on stack.
(Was allocating 4K of data instead of 512 bytes).

No test case as the original MDEV test cases is not usable for mtr.

UPDATE statement that is run in PS mode and uses positional parameter
handles columns declared with the clause DEFAULT NULL incorrectly in
case the clause DEFAULT is passed as actual value for the positional
parameter of the prepared statement. Similar issue happens in case
an expression specified in the DEFAULT clause of table's column definition.

The reason for incorrect processing of columns declared as DEFAULT NULL
is that setting of null flag for a field being updated was missed
in implementation of the method Item_param::assign_default().
The reason for incorrect handling of an expression in DEFAULT clause is
also missed saving of a field inside implementation of the method
Item_param::assign_default().

log_free_check(): Assert that the current thread is not holding
lock_sys.latch in any mode.

This fixes up commit 5f2dcd11

signal_hand(): Remove the cmake -DWITH_DBUG_TRACE=ON instrumentation.
It can cause a crash on shutdown when the only other thread is
waiting in wait_for_signal_thread_to_end().

innodb.autoinc_debug: Correct the test case for predictable deadlock.

In the JSON functions, the debug injection for stack overflows is
inaccurate and may cause actual stack overflows. Let us simply
inject stack overflow errors without actually relying on the ability
of check_stack_overrun() to do so.

Reviewed by: Rucha Deodhar

Fix a scenario where `mariabackup --prepare` fails with assertion
`!m_modifications || !recv_no_log_write'  in `mtr_t::commit()`. This
happens if the prepare step of the backup encounters a data directory
which happens to store wsrep xid position in TRX SYS page (this is no
longer the case since 10.3.5). And since MDEV-17458,
`trx_rseg_array_init()` handles this case by copying the xid position
to rollback segments, before clearing the xid from TRX SYS page.
However, this step should be avoided when `trx_rseg_array_init()` is
invoked from mariabackup. The relevant code was surrounded by the
condition `srv_operation == SRV_OPERATION_NORMAL`. An additional check
ensures that we are not trying to copy a xid position which has
already zeroed.

MDEV-33502 Slowdown when running nested statement with many partitions
caused this error as I failed to take into account bigendian architectures.

This patch also introduces bitmap_import() and bitmap_export() to be used
when one wants to store bitmaps in files/logs in a portable way.
Reviewed-by: Kristian Nielsen <knielsen@knielsen-hq.org>

This will makes it easier to find out what replication workers are
doing and what they are waiting for.

Things changed in processlist:
- Slave_SQL time was not consistent. Now time for state "Slave has
  read all relay log; waiting for more updates" shows how long it has
  waited for getting the next event.
- Slave_worker threads did often show "Closing tables" for a long
  time.  Now the state is reverted to the previous state after
  "Closing tables" is done.
- Commit and Rollback states where not shown for replication (and some
  other threads). Now Commit and Rollback states are always shown and
  the state is reverted to previous state when the Commit/Rollback
  have finished.

Code changes:
- Added thd->set_time_for_next_stage() for parallel replication when
  when starting to wait for prior transactions to commit, group commit,
  and FTWRL and for free space in thread pool.
  Before we reset the time only after the above events.
- Moved THD_STAGE_INFO(stage_rollback) and THD_STAGE_INFO(stage_commit)
  from sql_parse.cc to transaction.cc to ensure this is done for
  all commits and not only 'normal connection queries'.

Test case changes:
- close_thread_tables() reverting stage to previous stage caused the
  counter in performance_schema to be increased. In many case it is
  the 'sql/starting' stage that was effected.
- We only change to "Commit" stage if there is a need for a commit.
  This caused some "Commit" stages to disapper from perfschema reports.

TODO in 11.#:
- Slave_IO always showes "Waiting for master to send event" and the time is
  from SLAVE START. We should in 11.# change this to be the time since
  reading the last event.

The issue here is ha_innobase::get_auto_increment() could cause a
deadlock involving auto-increment lock and rollback the transaction
implicitly. For such cases, storage engines usually call
thd_mark_transaction_to_rollback() to inform SQL engine about it which
in turn takes appropriate actions and close the transaction. In innodb,
we call it while converting Innodb error code to MySQL.

However, since ::innobase_get_autoinc() returns void, we skip the call
for error code conversion and also miss marking the transaction for
rollback for deadlock error. We assert eventually while releasing a
savepoint as the transaction state is not active.

Since convert_error_code_to_mysql() is handling some generic error
handling part, like invoking the callback when needed, we should call
that function in ha_innobase::get_auto_increment() even if we don't
return the resulting mysql error code back.

MDEV-33582 Add more warnings to be able to better diagnose network issues

- Disabled "Semisync ack receiver got hangup" warning
  - One could get this warning from semisync if running
    mtr --mysqld=log-warnings=3 rpl.rpl_semi_sync_shutdown_await_ack
- Fixed result file for engines/funcs/rpl_get_lock.test

Problem:
========
 During upgrade, InnoDB does write the redo log for adjusting
the tablespace size or tablespace flags even before the log
has upgraded to configured format. This could lead to data
inconsistent if any crash happened during upgrade process.

Fix:
===
srv_start(): Write the tablespace flags adjustment, increased
tablespace size redo log only after redo log upgradation.

log_write_low(), log_reserve_and_write_fast(): Check whether
the redo log is in physical format.

- During update operation, InnoDB should avoid the initializing
the FTS_DOC_ID of foreign table if the foreign table is discarded

- Adjust the test case to check whether all tablespaces
are encrypted by comparing it with existing table count.

Warnings are added to net_server.cc when
global_system_variables.log_warnings >= 4.

When the above condition holds then:
- All communication errors from net_serv.cc is also written to the
  error log.
- In case of a of not being able to read or write a packet, a more
  detailed error is given.

Other things:
- Added detection of slaves that has hangup to Ack_receiver::run()
- vio_close() is now first marking the socket closed before closing it.
  The reason for this is to ensure that the connection that gets a read
  error can check if the reason was that the socket was closed.
- Add a new state to vio to be able to detect if vio is acive, shutdown or
  closed. This is used to detect if socket is closed by another thread.
- Testing of the new warnings is done in rpl_get_lock.test
- Suppress some of the new warnings in mtr to allow one to run some of
  the tests with -mysqld=--log-warnings=4. All test in the 'rpl' suite
  can now be run with this option.
 - Ensure that global.log_warnings are restored at test end in a way
   that allows one to use mtr --mysqld=--log-warnings=4.

Reviewed-by: <serg@mariadb.org>,<brandon.nesterenko@mariadb.com>

Like the fix for MDEV-32753 and MDEV-33242, spider init queries
creates new connections that use the global sql_mode of the existing
connection.