MDEV-13063 Server crashes in intern_plugin_lock or assertion `plugin_ptr->ref_count == 1' fails in plugin_init

if a forced plugin is disabled (for any reason, e.g. invalid command-line
option) - it's an error

This is actually a legacy bug:
SQL_SELECT::test_quick_select() was called
with SQL_SELECT::head not set.
It looks like that this problem can be
reproduced only on queries with ORDER BY
that use IN predicates converted to semi-joins.

This patch corrects the fix for bug mdev-7599.
When the min/max optimization of the function
opt_sum_query() optimizes away all tables of
a subquery it should not ever be rolled back.

If the optimizer chose an execution plan where
a semi-join nest were materialized and the
result of materialization was scanned to access
other tables by ref access it could build a key
over columns of the tables from the nest that
were actually inaccessible.
The patch performs a proper check whether a key
that uses columns of the tables from a materialized
semi-join nest can be employed to access outer tables.

buf_page_get_gen(): Remove the error log messages about
page flushing and eviction when
innodb_change_buffering_debug=1 is in effect.

Added forgoten method of Item_func_sp to make it correctly work with LEFT/RIGHT JOIN.
Fixed inconsistency with the null table caches.

Problem:-
This crash happens because logged stmt is quite big and while writing
Annotate_rows_log_event it throws EFBIG error  but we ignore this error
and do not call cache_data->set_incident().

Solution:-
When we normally write Binlog_log_event we check for error EFBIG, but we did
do this for Annotate_rows_log_event. We check for this error and call
cache_data->set_incident() accordingly.

# Conflicts:
#	sql/log.cc

This is another correction of the patch for bug mdev-12670.
If a derived table is merged into a select with STRAIGHT_JOIN
modifier all IN subquery predicates contained in the
specification of the derived table cannot be subject to
conversion to semi-joins.

This patch is a correction of the patch for bug mdev-12670.
With the current code handling semi-joins the following must
be taken into account.
Conversion of an IN subquery predicate into semi-join
has to be blocked if the predicate occurs:
(a) in the ON expression of an outer join
(b) in the ON expression of an inner join embedded directly
    or indirectly in the inner nest of an outer join.
The patch for mdev-12670 blocked conversion to semi-joins only
in the case (a), but not in the case (b). This patch blocks
the conversion in both cases.

When an IN subquery predicate was converted to a semi-join that were
materialized and the result of the materialization happened to be
the last in the execution plan then any conjunctive condition with RAND()
turned out to be lost.

Fixed by attaching this condition to the last top base table.

with a specially corrupted master.info one can
get an invalid heartbeat_period that will
trigger a heap overflow.

At some conditions the function opt_sum_query() can apply MIN/MAX
optimizations to to Item_sum objects of a select These optimizations
becomes invalid if this select is the subquery of an IN subquery
predicate that is converted to a EXISTS subquery. Thus in this case
the MIX/MAX optimizations that have been applied in opt_sum_query()
must be rolled back.
This bug appeared in 5.3 when the code for the cost base choice between
materialization and in-to-exists transformation of non-correlated
IN subqueries was introduced. Before this code in-to-exists
transformations were always performed before the call of opt_sum_query().

A better way of finding mysqld

The code that blocked conversion of a IN subselect pedicate to a semi-join
if it occurred in the ON expression of an outer join did not do it correctly.
As a result, the conversion was blocked for IN subselect predicates
encountered in ON expressions of INNER joins or in WHERE conditions
of mergeable views / derived tables. This patch fixes this problem.

This patch corrects the fix for the bug mdev-10693.
It is critical for the function get_best_combination() not to call
create_ref_for_key() for constant tables.
This bug could manifest itself only in multi-table subqueries where
one of the tables is accessed by a constant primary key.

/home/travis/build/MariaDB/server/extra/mysqld_safe_helper.c:62:21: warning: too many arguments in call to 'do_usage'
    do_usage(argv[0]);
    ~~~~~~~~        ^
1 warning generated.

The code that chooses between materialization of a non-correlated
IN subquery and its transformation into an EXISTS correlated
subquery assumes that the execution plan for the outer select
has been already built. However it was not always so if subqueries
occurred in the expressions used for ref access to tables of
the outer select. A call of the function create_ref_for_key() in
get_best_combination() could trigger a premature execution of
the above mentioned code when the execution plan structures for
the outer select were not fully built. This could cause a crash
of the server.

The fix postpones the calls of create_ref_for_key() until the
structures for the execution plan is fully built.

of course, this combination can never succeed,
we must fail to connect here.

MDEV-12230 include/my_sys.h:600:43: error: unknown type name ‘PSI_file_key’" when -DWITHOUT_SERVER=1

cherry-pick 2c2bd8c1 (MDEV-12261 build failure without P_S) from 10.0

it could be
* O_SEARCH on Illumos
* O_EXEC on FreeBSD
* O_PATH on Linux
ugh

way-too-smart compilers don't like the "confusing indentation"

The motivation for this is that Perl is moving towards not having
current directory ./ in @INC by default. This is causing
mysql-test-run.pl to fail in latest Debian Unstable:

  https://lists.debian.org/debian-devel-announce/2016/08/msg00013.html

However, we have `use "lib"`, there is no need for current directory
in @INC, except for a gross hack. In mtr_cases.pm, there is a
`require "mtr_misc.pl"`, which hides mtr_misc.pl away in mtr_cases
namespace. And things only work because mysql-test-run.pl loads it
with a different name, `require "lib/mtr_misc.pl"`! (Perl will
`require` only once for each unique filename).

Fix this by only using `require` in main program, and referencing
functions with :: scope from other namespaces. For multi-use in
different namespaces, proper `use` modules should be used.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Also fixed a wrong result for a test case for mdev-7691
(the alternative one).
The test  cases for all these bug have materialized semi-joins used
inside dependent sub-queries.

The patch actually reverts the change inroduced by Monty in 2003.
It looks like this change is not valid anymore after the implementation
of semi-joins.
Adjusted output from EXPLAIN for many other test cases.

The test was unnecessarily depending on InnoDB purge, which can
sometimes fail to proceed.

Let us rewrite the test to use BEGIN;INSERT;ROLLBACK to cause the
immediate removal of the desired records.

shouldn't have been added in the first place, MariaDB Server is GPLv2

While writing comments if database object names has a new
line character, then next line is considered a command, rather
than a comment.
This patch fixes the way comments are constructed in mysqldump.

(cherry picked from commit 1099f9d17b1c697c2760f86556f5bae7d202b444)

failed with SELECT SQ, TEXT field

The functon find_all_keys does call Item_subselect::walk, which calls walk() for the subquery
The issue is that when a field is represented by Item_outer_ref(Item_direct_ref(Item_copy_string( ...))).
Item_copy_string does have a pointer to an Item_field in Item_copy::item but does not implement Item::walk method, so we are not
able to set the bitmap for that field. This is the reason why the assert fails.

Fixed by adding the walk method to Item_copy class.

Changed MYSQL_OPT_SSL_MODE to be the same as in 5.6 (ABI compatibility).

(cherry picked from commit 47bb4eb5df1629b5d5e30aebfa9d7a6d74388a5d)