in file buf0mtflu.cc line 570.

Analysis: Real timing bug, we should take the mutex before we
try to send those shutdown messages, that would make sure
that threads doing a unfinished flush (they have acquired
this mutex) have time to do their work before we add shutdown
messages to work queue. Currently, we just add those shutdown
messages to work queue and code assumes that at flush, there
is constant number of items to be processed and thus
leading to assertion.

Forgot the code

- Add support for DELETE .. RETURNING statement in ANALYZE code.

variables and reduce the number of ifdef's

- In print_explain_row(), do not forget to print r_rows.
- Switch Explain_update from using its own counters to re-using
  Table_access_tracker.
- Make ANALYZE UPDATE code structure uniform with ANALYZE DELETE.

add a comment

-Wl,-z,relro,-z,now
-pie
-fstack-protector --param=ssp-buffer-size=4
-D_FORTIFY_SOURCE=2

move MY_CHECK_C_COMPILER_FLAG and MY_CHECK_CXX_COMPILER_FLAG
to a separate file, introduce MY_CHECK_AND_SET_COMPILER_FLAG,
use it where possible.

This reverts commit 0bf9fd89.

        Scripts added that create OpenGIS-required views and tables they're based upon.

Conflicts:
	storage/xtradb/handler/ha_innodb.cc

be set to unsupported value.

MDEV-6350: Excessive unnecessary memory allocation at InnoDB/XtraDB
startup if LZO is installed.

In JOIN_TAB::update_explain_data(), take into account that
- the table that may have pre-sorted is the first non-const table
- Tables that are eliminated by table elimination are marked
  as const tables, but are not present in the Explain data structures

- "ANALYZE $stmt" should discard select's output, but it should still
  evaluate the output columns (otherwise, subqueries in select list
  are not executed)
- SHOW EXPLAIN's code practice of calling JOIN::save_explain_data()
  after JOIN::exec() is disastrous for ANALYZE, because it resets
  all counters after the first execution. It is stopped
  = "Late" test_if_skip_sort_order() calls explicitly update their part
    of the query plan.
  = Also, I had to rewrite I_S optimization to actually have optimization
    and execution stages.

* Introduce a set of PLUGIN_xxx cmake options with values
  NO, STATIC, DYNAMIC, AUTO, YES (abort if plugin is not compiled)
* Deprecate redundant and ambiguous WITH_xxx, WITH_PLUGIN_xxx,
  WITH_xxx_STORAGE_ENGINE, WITHOUT_xxx, WITHOUT_PLUGIN_xxx,
  WITHOUT_xxx_STORAGE_ENGINE
* Actually check whether a plugin is disabled (DISABLED keyword was
  always present, but it was ignored until now).
* Support conditionally disabled plugins - keyword ONLY_IF
* Use ONLY_IF for conditionally skipping plugins, instead of
  doing MYSQL_ADD_PLUGIN conditionally as before. Because if
  MYSQL_ADD_PLUGIN isn't done at all, PLUGIN_xxx=YES cannot work.

mark path-related variables (AIO_LIBRARY, ODBC_LIBRARY, ODBC_INCLUDE_DIR,
Thrift_LIBS, Thrift_INCLUDE_DIRS, CRYPTO_LIBRARY, OPENSSL_LIBRARIES,
OPENSSL_ROOT_DIR, OPENSSL_INCLUDE_DIR) as advanced - paths are
automatically discovered by cmake.

mark few choice variables (ENABLED_LOCAL_INFILE, WITHOUT_SERVER,
DISABLE_SHARED) as not advanced - they are user choices, not automatically
configured values.

remove unused BACKUP_TEST variable.

* enum values to index different ACL tables, instead of hard-coded numbers
  (even different in diffent functions).
* move TABLE_LIST initialization into open_grant_tables()
  and use it everywhere
* change few my_bool's to bool's