Added unregistering writers in case of log error.
Added more debugging control about adding/removing writers to the buffers.

           SELECT .. LIMIT 0 (new variant)

This is another attempt to fix the problem of mdev-14515.

update table->pos_in_table_list during prepare,
just like it's done in normal execution.

otherwise it'll be a dangling pointer

adjust tests

rewrite tautological engine descriptions

The order of outputting stored procedures is important. Stored
procedures must be available on view creation, for views which make use
of them. Make sure to print them before outputting tables.

Undo the revert that happened by mystake in commit 7fca4b50.

GCC-8 introduced multiple warnings and increased the level of
strictness.

* -Wshadow will warn if a local variable shadows a typedef.
* GCC will also warn when memsetting a non-trivial type.
  In this case a non-trivial type can not have a custom constructor.
  For all intents and purposes, the class is trivially-copyable.
* GCC will also warn if you use too many paranthesses which are not
necessary

This reverts commit 1735fa34.

Assign all tests added via MY_ADD_TEST to a bogus default_ignore target,
so that they are not ran by default when doing bare make test. Add default
test named MTR that calls mysql-test-run suite, which is now the single
test run by make test.

In consequence, modified unit/suite.pm to exclude the MTR test and run the
real ctests flagged for default_ignore target, thus no circular
loop.

This is happening because they are declared as packed
and clang has -Waddress-of-packed-member when passing the
address of a packed member, a legit concern on different
architectures. The easiest way to get rid of the errors is to
remove the packed attribute from said structs.

Fix build on macOS 10.13:

39dceaae MDEV-10983: TokuDB does not compile on OS X 10.12
Make use of a different function to get the current tid.
Additionally, librt doesn't exist on OS X. Use System library instead.

 storage/tokudb/PerconaFT/cmake_modules/TokuFeatureDetection.cmake | 4 +++-
 storage/tokudb/PerconaFT/portability/portability.cc               | 9 ++++++++-
 storage/tokudb/PerconaFT/portability/tests/test-xid.cc            | 9 ++++++++-
 storage/tokudb/PerconaFT/portability/toku_config.h.in             | 1 +
 4 files changed, 20 insertions(+), 3 deletions(-)

The bug arises when one uses --auto-generate-sql-guid-primary (and
--auto-generate-sql-secondary-indexes) with mysqlslap and also have
sql_mode=STRICT_TRANS_TABLE.

When using this option, mysqlslap should create a column with varchar(36),
but it appears to create it as a varchar(32) only. Then if one has
sql_mode=STRICT_TRANS_TABLES, it throws an error, like:

  mysqlslap: Cannot run query INSERT INTO t1 VALUES (...)
  ERROR : Data too long for column 'id' at row 1

Upstream bug report: BUG#80329.

Partially revert 4ef74979
that caused regression.

Any ssl- option must imply use_ssl=1, even if mysql_set_ssl() was not
used.

For non-semi-join subquery optimization we do a cost based decision between
Materialisation and IN -> EXIST transformation. The issue in this case is that for IN->EXIST transformation
we run JOIN::reoptimize with the IN->EXISt conditions and we come up with a new query plan. But when we compare
the cost with Materialization, we make the decision to chose Materialization so we need to restore the query plan
for Materilization.
The saving and restoring for keyuse array and join_tab keyuse is only done when we have atleast
one element in the keyuse_array , we are now changing to do it even for 0 elements to main the generality.

gdb's "set args" equivalent for lldb would be "settings set target.run-args",
however it doesn't play well with double dashed args (--).

           upon SELECT .. LIMIT 0

The code must differentiate between a SELECT with contradictory
WHERE/HAVING and one with LIMIT 0.
Also for the latter printed 'Zero limit' instead of 'Impossible where'
in the EXPLAIN output.

It should work ok on all Unixes, but on Windows ,only worked by accident
in the past, with client not being Unicode safe.

It stopped working with Visual Studio 2017 15.7 update now.

When Item_insert_value needs a dummy field,
use zero-length Field_string, not Field_null.
The latter isn't compatible with CREATE ... SELECT.

Analyze core independently of max-save-datadir and max-save-core setting.

Increment $num_saved_cores only if core was actually saved.

"Move any core files from e.g. mysqltest" independently of
max-save-datadir setting. Note: it may overwrite core from mysqld, which
might not be desired (it did work this way even before).

MDEV-654 Assertion `share->now_transactional' failed in flush_log_for_bitmap on concurrent workload with Aria tables

Problem was that we the bitmap needs to be flushed before disabling
logging of redo entires, as writing the bitmap to disk by
background checkpoint may cause redo entries.

QUERY_DML_NO_SELECT flag added.

a better fix

fix another similar line

followup for 7828ba0d

multiple times with different arguments.

If the ON expression of an outer join is an OR formula with one
of the disjunct being a constant formula then the expression
cannot be null-rejected if the constant formula is true. Otherwise
it can be null-rejected and if so the outer join can be converted
into inner join. This optimization was added in the patch for
mdev-4817. Yet the code had a defect: if the query was used in
a stored procedure with parameters and the constant item contained
some of them then the value of this constant item depended on the
values of the parameters. With some parameters it may be true,
for others not. The validity of conversion to inner join is checked
only once and it happens only for the first call of procedure.
So if the  parameters in the first call allowed the conversion it
was done and next calls used the transformed query though there
could be calls whose parameters made the conversion invalid.

Fixed by cheking whether the constant disjunct in the ON expression
originally contained an SP parameter. If so the expression is not
considered as null-rejected. For this check a new item's attribute
was intruduced: Item::with_param. It is calculated for each item
by fix fields() functions.
Also moved the call of optimize_constant_subqueries() in
JOIN::optimize after the call of simplify_joins(). The reason
for this is that after the optimization introduced by the patch
for mdev-4817 simplify_joins() can use the results of execution
of non-expensive constant subqueries and this is not valid.

MDEV-13699: Assertion `!new_field->field_name.str || strlen(new_field->field_name.str) == new_field->field_name.length' failed in create_tmp_table on 2nd execution of PS with semijoin

The problem was that SJ (semi-join) used secondary list (array) of subquery select list. The items there was prepared once then cleaned up (but not really freed from memory because it was made in statement memory).
Original list was not prepared after first execution because select was removed by conversion to SJ.
The solution is to use original list but prepare it first.

in a specially crafted invalid packet, one can get end_pos < pos here

disable online alter add primary key for innodb, if the
table is opened/locked more than once in the current connection

(see assert in ha_innobase::add_index())

test case

Any expensive WHERE condition for a table-less query with
implicit aggregation was lost. As a result the used aggregate
functions were calculated over a non-empty set of rows even
in the case when the condition was false.