Post-merge fixes: minor perlification and get rid of an
annoying run-time warning (undef value in string comparison)

Closes #709

If a mtr test case has started two mysqld processes (replication tests),
then kills the first one and kills the second one before starting the
first (so at some point there are two mysqlds down), then the ./mtr
waiting process bricks and forgets to monitor the "expect" file of the
first mysqld, so it never gets started again, even when its contents is
changed to "restart".

A victim of this deficiency is at least galera.galera_gcache_recover.

The fix is to keep a list of all mysqlds we should wait to start, not
just one (the last one killed).

extra/mariabackup/fil_cur.cc:361:42: warning: format specifies type 'unsigned long' but the argument has type 'ib_int64_t' (aka 'long long') [-Wformat]
extra/mariabackup/fil_cur.cc:376:9: warning: format specifies type 'unsigned long' but the argument has type 'ib_int64_t' (aka 'long long') [-Wformat]
sql/handler.cc:6196:45: warning: format specifies type 'unsigned long' but the argument has type 'wsrep_trx_id_t' (aka 'unsigned long long') [-Wformat]
sql/log.cc:1681:16: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
sql/log.cc:1687:16: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
sql/wsrep_sst.cc:1388:86: warning: format specifies type 'long' but the argument has type 'wsrep_seqno_t' (aka 'long long') [-Wformat]
sql/wsrep_sst.cc:232:86: warning: format specifies type 'long' but the argument has type 'wsrep_seqno_t' (aka 'long long') [-Wformat]
storage/connect/filamdbf.cpp:450:47: warning: format specifies type 'short' but the argument has type 'int' [-Wformat]
storage/connect/filamdbf.cpp:970:47: warning: format specifies type 'short' but the argument has type 'int' [-Wformat]
storage/connect/inihandl.cpp:197:16: warning: address of array 'key->name' will always evaluate to 'true' [-Wpointer-bool-conversion]
storage/innobase/btr/btr0scrub.cc:151:17: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/innobase/buf/buf0buf.cc:5085:8: warning: nonnull parameter 'bpage' will evaluate to 'true' on first encounter [-Wpointer-bool-conversion]
storage/innobase/fil/fil0crypt.cc:2454:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/innobase/handler/ha_innodb.cc:18685:7: warning: format specifies type 'unsigned long' but the argument has type 'wsrep_trx_id_t' (aka 'unsigned long long') [-Wformat]
storage/innobase/row/row0mysql.cc:3319:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/innobase/row/row0mysql.cc:3327:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/maria/ma_norec.c:35:10: warning: implicit conversion from 'int' to 'my_bool' (aka 'char') changes value from 131 to -125 [-Wconstant-conversion]
storage/maria/ma_norec.c:42:10: warning: implicit conversion from 'int' to 'my_bool' (aka 'char') changes value from 131 to -125 [-Wconstant-conversion]
storage/maria/ma_test2.c:1009:12: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
storage/maria/ma_test2.c:1010:12: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
storage/mroonga/ha_mroonga.cpp:9189:44: warning: use of logical '&&' with constant operand [-Wconstant-logical-operand]
storage/mroonga/vendor/groonga/lib/expr.c:4987:22: warning: comparison of constant -1 with expression of type 'grn_operator' is always false [-Wtautological-constant-out-of-range-compare]
storage/xtradb/btr/btr0scrub.cc:151:17: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/xtradb/buf/buf0buf.cc:5047:8: warning: nonnull parameter 'bpage' will evaluate to 'true' on first encounter [-Wpointer-bool-conversion]
storage/xtradb/fil/fil0crypt.cc:2454:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/xtradb/row/row0mysql.cc:3324:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/xtradb/row/row0mysql.cc:3332:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
unittest/sql/mf_iocache-t.cc:120:35: warning: format specifies type 'unsigned long' but the argument has type 'int' [-Wformat]
unittest/sql/mf_iocache-t.cc:96:35: note: expanded from macro 'INFO_TAIL'

don't use C11 atomics unless HAVE_GCC_C11_ATOMICS is defined

(failed configure with old clang)

galera_new_cluster.sh: unused variables

Check if the argument of the FLUSH TABLE is a VIEW and handle it
accordingly.

This regression was introduced in MDEV-16515.
We would fail to drop a temporary table on client disconnect,
because trx_is_interrupted() would hold. To add insult to
injury, in MariaDB 10.1, InnoDB temporary tables are actually
persistent, so the garbage temporary tables will never be dropped.

row_drop_table_for_mysql(): If several iterations of
buf_LRU_drop_page_hash_for_tablespace() are needed,
do not interrupt dropping a temporary table even after
the transaction was marked as killed.

Server shutdown will still terminate the loop, and also DROP TABLE
of persistent tables will keep checking if the execution was aborted.

This reverts commit 75dfd4ac.

Plugin version name fixed.

Let '\\' and '/' symbols to be part of a group name.

Merged https://github.com/MariaDB/server/pull/617 authored by
Colin Mollenhour.

MDEV-14851: galera_recovery to read correct configuration file sections

Problem was that a parallel open of a table, overwrote info->state that
was in used by repair.

Fixed by changing _ma_tmp_disable_logging_for_table() to use
a new state buffer state.no_logging to store the temporary state.

Other things:
- Use original number of rows when retrying repair to get rid of a
  potential warning "Number of rows changed from X to Y"
- Changed maria_commit() to make it easier to merge with 10.4
- If table is not locked (like with show commands), use the global
  number of rows as the local number may not be up to date.
  (Minor not critical fix)
- Added some missing DBUG_RETURN

MDEV-10754 wsrep_sst_rsync does not support innodb_data_home_dir

trx_purge_add_update_undo_to_history(): Relax the too strict assertion
by removing the condition on srv_fast_shutdown (innodb_fast_shutdown).
Rollback is allowed during any form of shutdown.

buf_dump(): Only generate the output when shutdown is in progress.

log_write_up_to(): Only generate the output before actually writing
to the redo log files.

srv_purge_should_exit(): Rate-limit the output, and instead of
displaying the work done, indicate the work that remains to be done
until the completion of the slow shutdown.

Item_subselect::is_expensive() used to return FALSE (Inexpensive) whenever
it saw that one of SELECTs in the Subquery's UNION is degenerate. It
ignored the fact that other parts of the UNION might not be inexpensive,
including the case where pther parts of the UNION have no query plan yet.

For a subquery in form col >= ANY (SELECT 'foo' UNION SELECT 'bar')
this would cause the query to be considered inexpensive when there is
no query plan for the second part of the UNION, which in turn would
cause the SELECT 'foo' to compute and free itself while still inside
JOIN::optimize for that SELECT (See MDEV comment for full description).

MDEV-15475: Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' failed on EXPLAIN EXTENDED with constant table and view

Print constant ISNULL value independent.
Fix of printing of view FRM and CREATE VIEW output

If we have a 2+ node cluster which is replicating from an async master
and the binlog_format is set to STATEMENT and multi-row inserts are executed
on a table with an auto_increment column such that values are automatically
generated by MySQL, then the server node generates wrong auto_increment
values, which are different from what was generated on the async master.

The causes and fixes:

1. We need to improve processing of changing the auto-increment values
after changing the cluster size.

2. If wsrep auto_increment_control switched on during operation of
the node, then we should immediately update the auto_increment_increment
and auto_increment_offset global variables, without waiting of the next
invocation of the wsrep_view_handler_cb() callback. In the current version
these variables retain its initial values if wsrep_auto_increment_control
is switched on during operation of the node, which leads to inconsistent
results on the different nodes in some scenarios.

3. If wsrep auto_increment_control switched off during operation of the node,
then we must return the original values of the auto_increment_increment and
auto_increment_offset global variables, as the user has set. To make this
possible, we need to add a "shadow copies" of these variables (which stores
the latest values set by the user).

MDEV-15933 Cannot resume Node SYNCED state when wsrep_desync is done after FTWRL

Moved parts of mysql.test to mysql_not_windows.test

Manually setting wsrep_desync after FTWRL should not be allowed.

Use real DACL instead of NULL DACL.
Grant Everyone just read/write access to pipe
(instead of all access like previously with NULL ACL)

truncate incorrect values in convert_period_to_month() so that
PERIOD_DIFF never returns a value outside of 2^23 range.

And, for safety, increase buffer sizes for int10_to_str
to be sufficienly big for any int10_to_str result.

* Backport from 10.4 to resolve dependency problem

Using the dependency syntax from 10.4 branch because {$LIBSSL} can not
be used.

Fixes after review and correction of the problems caused by the fact that during the SST innodb plugin is not yet initialized, as well as problems with running tests from the root user (not directly related to the MDEV-10754).

not empty

We should swap the list only when list is not empty.

InnoDB executed code that is mean to execute only when Galera
is used and in bad luck one of the transactions is selected
incorrectly as deadlock victim. Fixed by adding wsrep_on_trx()
condition before entering actual Galera transaction handling.

No always repeatable test case for this issue is known.