Chery-picked commits from codership/mysql-wsrep.

MW-284: Slave I/O retry on ER_COM_UNKNOWN_ERROR

Slave would treat ER_COM_UNKNOWN_ERROR as fatal error and stop.
The fix here is to treat it as a network error and rely on the
built-in mechanism to retry.

MW-284: Add an MTR test

Clang warns on this code because it is memsetting over a vtable contained in a
struct in the best_positions array. The diagnostic text is:

mariadb/sql/sql_select.cc:24462:10: error: destination for this 'memset' call is
a pointer to class containing a dynamic class 'Duplicate_weedout_picker'; vtable
pointer will be overwritten [-Werror,-Wdynamic-class-memaccess]
  memset(best_positions, 0, sizeof(POSITION) * (table_count + 1));
  ~~~~~~ ^

Patch contributed by David Gow.

MDEV-9884: Existing /var/lib/mysql/.sst directory (with contents) causes SST to fail with xtrabackup-v2

[Fix taken from https://github.com/percona/percona-xtradb-
cluster/commit/b3ee75949ed82b88f355ca2e26431350cc1c89ac]

During SST, the receiver node creates .sst directory under
datadir to process/prepare the received data and removes it
at the end of the process. In case of error, this directory,
however, was not removed, which later caused subsequent SSTs
to fail. Fixed by removing this directory at the beginning
of SST if it existed.

as it fails on new builders.

msxml6 is found on all Windows we support, thus there is no reason to
search for it.

1.04.0006

5.6.29-76.2

5.6.30

in case of prelocking, don't check table->grant.privilege
in handler::external_lock(), do it in
handler::start_stmt().

Fixed memory leaks in gen_lex_hash.

take into account that agg_arg_charsets_for_comparison()
can replace Item_field's with Item_func_conv_charset

        Added SSL support to the mysqlbinlog.

Problem was that notify_shared_lock() didn't abort an insert delayed thread
if it was in thr_upgrade_write_delay_lock().

ALTER TABLE first takes a weak_mdl_lock, then a thr_lock and then tries to upgrade
the mdl_lock.
Delayed insert thread first takes a mdl lock followed by a
thr_upgrade_write_delay_lock()
This caused insert delay to wait for alter table in thr_lock, while
alter table was waiting for the mdl lock by insert delay.

Fixed by telling mdl to run thr_lock_abort() for the insert delay thread table.
We also set thd->mysys_var->abort to 1 for the delay thread when it's killed
by alter table to ensure it doesn't ever get locked in thr_lock.

restore the error message that was removed by mistake in ec38c1bb

Backport a part of

commit 439f75f8
Author: Kristian Nielsen <knielsen@knielsen-hq.org>
Date:   Mon Jun 30 13:59:21 2014 +0200

    Fix test failures in rpl.rpl_checksum and rpl.rpl_gtid_errorlog.

- Fixed wait condition in kill_processlist-6619
- Updated Ssl_chiper for openssl tests
- Added supression for valgrinds when using libcrypto
- Fixed wrong argument to pthread_mutex in server_audit.c when compiling with debug
- Adding missing debug_sync_update() to debug_sync.h
- Added initializers to some variables and fixed error handling in jsonudf.cpp
- Fixed cluster_filter_unpack_varchar which doesn't have a stable index type.
- Updated compiler_warnings.supp

  when joining a table to a MYSQL indexed table.
  modified:   storage/connect/myconn.cpp
  modified:   storage/connect/myconn.h
  modified:   storage/connect/tabmysql.cpp

- Add more tests to the mysql_index.test file
  modified:   storage/connect/mysql-test/connect/r/mysql_index.result
  modified:   storage/connect/mysql-test/connect/t/mysql_index.test

- Fix and error causing remote indexing to fail when for not unique index.
  Was experienced with MYSQL, ODBC and JDBC tables.
  modified:   storage/connect/connect.cc

- Fix MDEV-9966 (zero lines returned)
  modified:   storage/connect/ha_connect.cc
  modified:   storage/federatedx/ha_federatedx.cc

Fixed wait condition to wait for InnoDB to actually acquire row locks instead
of waiting for thread to enter "Searching rows for update" state (which happens
earlier).

Also use default wait timeout, 2 seconds can be too few for threads to enter
appropriate state.

Spider:
  SunPro only supports array declarations with
  constant size. Spider already has a workaround for
  that, inside #ifdef _MSC_VER. Enable this code
  also for __SUNPRO_CC

Connect:
  Don't use anonymous union.
  Cast for mmap.
  Don't pass gcc-ish -W... options to SunPro

This fixes:
MDEV-7693 MariaDB - mysql-test - SUITE:funcs_1 - funcs_1.is_tables_mysql is failing on TABLE_COLLATION /DATABASE_COLLATION
MDEV-8487 mysql-test - main.information_schema 'xtradb' fails
MDEV-8486 mysql-test - main.bootstrap fails

disable the test when DES doesn't work

* check for openssl errors in DES_ENCRYPT/DES_DECRYPT
* disable the test when DES doesn't work
* also disable main.func_des_encrypt

disable the test when crypt(3) doesn't work

add a test case

let handler::check_if_supported_inplace_alter()
(that detects frm-only changes) to work for partitioned
tables too.

clarify Alter_inplace_info::ALTER_PARTITIONED

use get_current_user() to distinguish user name without
a hostname and a role name.

move privilege checks inside mysql_show_grants() to remove
duplicate get_current_user() calls