5.5 version. for cmake, not autotools.

The problem was increment of aborted_threads variable due to thd->killed which was set when threadpool connection was terminated .  The fix is not to set thd->killed anymore, there is no real reason for doing it..

Added a test that checks that status variable aborted_clients does not grow for ordinary disconnects, and that successful KILL increments this variable.

MDEV-214 lp:967242 Wrong result with JOIN, AND in ON condition, multi-part key, GROUP BY, subquery and OR in WHERE

The problem was in the code (update_const_equal_items()) which marked
index parts constant independently of the place where the equality was used.
In the test suite it marked t2_1.c part constant despite the fact that
it connected by OR with other expression.

Solution is to mark constant only top equalities connected with AND.

Fix is to set  maybe_null  flag for Item_func_last_day.

unnecessary date->string->date conversion

Create an Item_cache based on item's cmp_type, not result_type in 
subselect_engine.

Use result_field in Item_cache_temporal::cache_value(),
just like all other Item_cache*::cache_value() do.

  Points and lines should disappear if we got negative D.
  To make it work properly inside the GEOMETRYCOLLECTION,
  we add the empty operation there.

bug #986977 Assertion `!cur_p->event' failed in Gcalc_scan_iterator::arrange_event(int, int).
  The double->inernal coord conversion produced -0 (minus zero) on some data.
  That minus-zero produces invalid comparison results when compared agains plus-zero.
  So we fixed the gcalc_set_double() to avoid it.

per-file comments:
  mysql-test/r/gis-precise.result
        result updated.
  mysql-test/t/gis-precise.test
        tests for #977021 and #986977 added.
  sql/gcalc_slicescan.cc
        bug #986977. The gcalc_set_double fixed to not produce minus-zero.
  sql/item_geofunc.cc
        bug #977021. Add the NOOP for the disappearing features.

MDEV-216 lp:976104 - Assertion `0' failed in my_message_sql on UPDATE IGNORE, or unknown error on release build

Don't send_error at the end of mysql_multi_update() if select failed.
The error, if there was any, was already sent by mysql_select

Analysis:

The reason for the wrong result is the interaction between constant
optimization (in this case 1-row table) and subquery optimization.

- First the outer query is optimized, and 'make_join_statistics' finds that
table t2 has one row, reads that row, and marks the whole table as constant.
This also means that all fields of t2 are constant.

- Next, we optimize the subquery in the end of the outer 'make_join_statistics'.
The field 'f2' is considered constant, with value '3'. The subquery predicate
is rewritten as the constant TRUE.

- The outer query execution detects early that the whole query result is empty
and calls 'return_zero_rows'. Since the query is with implicit grouping, we
have to produce one row with special values for the aggregates (depending on
each aggregate function), and NULL values for all non-aggregate fields.  This
function calls 'no_rows_in_result' to set each aggregate function to the
default value when it aggregates over an empty result, and then calls
'send_data', which in turn evaluates each Item in the SELECT list.

- When evaluation reaches the subquery predicate, it executes the subquery
with field 'f2' having a constant value '3', and the subquery produces the
incorrect result '7'.

Solution:

Implement Item::no_rows_in_result for all subquery predicates. In order to
make this work, it is also needed to make all val_* methods of all subquery
predicates respect the Item_subselect::forced_const flag. Otherwise subqueries
are executed anyways, and override the default value set by no_rows_in_result
with whatever result is produced from the subquery evaluation.

remove a redundant line in Makefile.am

install all private headers in mysql/private/

As part of derived tables redesign, values for VIEW_ALGORITHM_MERGE and VIEW_ALGORITHM_TMPTABLE have changed from (former values 1 rsp 2 , new values 5 rsp 9).

This lead to the problem that views, created with version 5.2  or earlier would not work in all situations  (e.g "SHOW CREATE VIEW"), or with mysqldump.

The fix is to restore backward compatibility for the from file, and convert algorithm={1,2} in the frm to {5,9} when reading .frm from disk, and store backward compatible values when writing from to disk. 

Also allow processing correct processing for "invalid" .frms created with MariaDB 5.3/5.5 GA releases (where algorithm stored in memory matched the one stored in frm).

  Points and lines should disappear if we got negative D.
  To make it work properly inside the GEOMETRYCOLLECTION,
  we add the empty operation there.

bug #986977 Assertion `!cur_p->event' failed in Gcalc_scan_iterator::arrange_event(int, int).
  The double->inernal coord conversion produced -0 (minus zero) on some data.
  That minus-zero produces invalid comparison results when compared agains plus-zero.
  So we fixed the gcalc_set_double() to avoid it.

per-file comments:
  mysql-test/r/gis-precise.result
        result updated.
  mysql-test/t/gis-precise.test
        tests for #977021 and #986977 added.
  sql/gcalc_slicescan.cc
        bug #986977. The gcalc_set_double fixed to not produce minus-zero.
  sql/item_geofunc.cc
        bug #977021. Add the NOOP for the disappearing features.

Fixed incorrect type casting which made all fields (except very first) changes to materialized table incorrect.
Saved list of view/derived table used items after expanding '*'.

BUG#978479: Wrong result (extra rows) with derived_with_keys+loosescan+semijoin=ON, materialization=OFF
- Part#2: Don't try to construct a LooseScan access on indexes that do not guarantee 
  index-ordered reads.

BUG#978479: Wrong result (extra rows) with derived_with_keys+loosescan+semijoin=ON, materialization=OFF
Part#1: make EXPLAIN's plan match the one by actual execution: 
Item_subselect::used_tables() should return the same value irrespectively 
of whether we're running an EXPLAIN or a SELECT.

MDEV-217 - Assertion `thd->stmt_arena != thd->progress.arena' failed in thd_progress_init on OPTIMIZE two tables when replaced by recreate

call thd_progress_end() in the copy_data_between_tables(), to match its
thd_progress_init().

(for example, one of them sets client capabilities by copying server capabilities)

We cannot fix them - let's tolerate them

for a plugin installed run-time

(--xxx=ON behaving as --xxx=FORCE)