on disconnect THD must clean user_var_events array before
dropping temporary tables. Otherwise when binlogging a DROP,
it'll access user_var_events, but they were allocated
in the already freed memroot.

take into account that argc can be 0
(if there were no commands on the command line)

Don't use a fixed buffer for X509_NAME_oneline() in the client.
Do as the server does - allocate it dynamically.

For a test - regenerate certificates to have the server cert with
a long subject.

MDEV-7585 Assertion `thd->is_error() || kill_errno || thd->killed == ABORT_QUERY' failed in ha_rows filesort

if we clear the error status (in THD::clear_error())
make sure to clear the thd->killed == KILL_BAD_DATA too,
because it was caused by the error that we're clearing.

Remove the too restrictive bugfix for bug#67088.
FIFO can be used for general/slow logs, but lseek() and fsync() on
FIFO fail. And open() needs to be non-blocking, in case the other
end isn't reading.

because current_thd is NULL and ER() causes sigsegv

The double call of ref used tables fixed.

MDEV-7126 replication slave - deadlock in terminate_slave_thread with stop slave and show variables of replication filters and show global status

Three-way deadlock:

  T1: SHOW GLOBAL STATUS
      -> acquire LOCK_status
  T2: STOP SLAVE
      -> acquire LOCK_active_mi
      -> terminate_slave_thread()
      -> -> cond_timedwait for handle_slave_sql to stop
  T3: sql slave thread (same applies to io thread)
      -> handle_slave_sql(), when exiting
      -> -> THD::add_status_to_global()
      -> -> -> wait for LOCK_status...
  T1: SHOW GLOBAL STATUS
      -> for "Slave_heartbeat_period" status variable
      -> -> show_heartbeat_period()
      -> -> -> wait for LOCK_active_mi

cherry-pick from 5.6:

  commit fc8b395898f40387b3468122bd0dae31e29a6fde
  Author: Venkatesh Duggirala <venkatesh.duggirala@oracle.com>
  Date:   Wed Jun 12 21:41:05 2013 +0530

    BUG#16904035-SHOW STATUS - EXCESSIVE LOCKING ON LOCK_ACTIVE_MI AND
    ACTIVE_MI->RLI->DATA_LOCK

    Problem: Excessive locking on lock_active_mi and rli->data_lock
    while executing any `show status like 'X'` command.

    Analysis: SHOW_FUNCs for Slave_running, Slave_retried_transactions,
    Slave_heartbeat_period, Slave_received_heartbeats,
    Slave_last_heartbeat are acquiring lock_active_mi and rli->data_lock
    to show their variable value. It is ok to show stale data while showing
    the status variables i.e., even if they miss one update, it will
    not cause any great trouble.

    Fix: Remove the locks from the above mentioned SHOW_FUNC functions.

Add a test case

Merge pull request #39 from openquery/MDEV-7977-mutex-unlock_LOCK_log-in-MYSQL_BIN_LOG_write_incident

MDEV-7977 MYSQL_BIN_LOG::write_incident failing to release LOCK_log

Taking into account implicit dependence of constant view field from nullable table of left join added.

Fixed finding real table to check if it turned to NULL (materialized view & derived taken into account)

Removed incorrect uninitialization.

save_prep_leaf_tables() made recursive to work with underlying view

Arena restoiring fixed in case of EOM.

convert_subq_to_sj() must check the results of in_equality->fix_fields()
call. It can fail in a meaningful way when e.g. we're trying to compare
columns with incompatible collations.

Cherry-picking https://github.com/olesalscheider/server/commit/fc4df415049271ef625783c31f2999e7d1bdc816
(it was a 10.1 pull request, we want it in 5.5)

MDEV-7820 Server crashes in in my_strcasecmp_utf8 on subquery in ORDER B...

It is possible for Item_field to have a NULL field_name. This is true if
the Item_field is created based on a field in a temporary table that has
no name. It is thus necessary to do a null check before attempting a
strcmp.

Removing a wrong assertion.

Multi-update do not need full list of leaf tables. It also do not use it on prepare (mysql_multi_update_prepare()).

This adds a unlock(LOCK_log) for the unlikely(!is_open()) branch

        The serve_audit_query_log_limit variable implemented.
        Also QUERY_DCL filter added.

Update test results after the patch for MDEV-7474.

when using function.

Merged upstream fix to Bug#16221433 MYSQL REJECTS QUERY DUE TO BAD
RESOLUTION OF NAMES IN HAVING; VIEW UNREADABLE
authored by Guilhem Bichot <guilhem.bichot@oracle.com>.

If the spatial key is used within an equality comparison, the comparison
does not produce relevant results generally as identical geometry can be
stored differently. Still, we want to support the operation. In order
to allow a hash join plan, we must define a key_length for Field_geom.

plugin_variable_update() can get NULL as a value for a string parameter.
Needs to be checked and handled properly.

JOIN::cur_dups_producing_tables was not maintained correctly in
the cases of greedy optimization (search_depth < n_tables).

Moved it to POSITION structure where it will be maintained automatically.

Removed POSITION::prefix_dups_producing_tables since its value can now
be calculated.

MDEV-7692 MariaDB - mysql-test - SUITE:percona - percona.innodb_sys_index 'xtradb' fails - @@version_comment

The test checked version_comment which is not helpful, and it would
cause the mismatch on any build apart from default source builds.
Fixed by removing the check