srv_conc_t::n_active: Correct the comment, and remove an
assertion that trivially holds now that the type is unsigned.

Disable the test encryption.innodb_encryption-page-compression
because the wait_condition would seem to time out deterministically.
MDEV-14814 has to be addressed in 10.2 separately.

Datafile::validate_first_page(): Do not invoke
page_size_t::page_size_t(flags) before validating the tablespace flags.
This avoids a crash in MDEV-15333 innodb.restart test case.
FIXME: Reduce the number of error messages. The first one is enough.

This performance regression was introduced in the MariaDB 10.1
file format incompatibility bug fix MDEV-11623 (MariaDB 10.1.21
and MariaDB 10.2.4) and partially fixed in MariaDB 10.1.25 in
MDEV-12610 without adding a regression test case.

On a normal startup (without crash recovery), InnoDB should not read
every .ibd data file, because this is slow. Like in MySQL, for now,
InnoDB will still open every data file (without reading), and it
will read every .ibd file for which an .isl file exists, or the
DATA DIRECTORY attribute has been specified for the table.

The test case shuts down InnoDB, moves data files, replaces them
with garbage, and then restarts InnoDB, expecting no messages to
be issued for the garbage files. (Some messages will for now be
issued for the table that uses the DATA DIRECTORY attribute.)
Finally, the test shuts down the server, restores the old data files,
and restarts again to drop the tables.

fil_open_single_table_tablespace(): Remove the condition on flags,
and only call fsp_flags_try_adjust() if validate==true
(reading the first page has been requested). The only caller with
validate==false is at server startup when we are processing all
records from SYS_TABLES. The flags passed to this function are
actually derived from SYS_TABLES.TYPE and SYS_TABLES.N_COLS,
and there never was any problem with SYS_TABLES in MariaDB 10.1.
The problem that MDEV-11623 was that incorrect tablespace flags
were computed and written to FSP_SPACE_FLAGS.

MDEV-9962: encryption.innodb_encryption_filekeys stalled waiting for key encryption threads to decrypt all required spaces

Test changes.

MDEV-14814: encryption.innodb_encryption-page-compression failed in buildbot with timeout on wait condition

Problem is that if pages are in buffer pool there is no need for
decrypt or page decompression operations.

Avoid NULL pointer dereference when shutting down after invalid parameters
were parsed.

fts_cmp_set_sync_doc_id(), fts_load_stopword(): Start the transaction
in read-only mode if innodb_read_only is set.

fts_update_sync_doc_id(), fts_commit_table(), fts_sync(),
fts_optimize_table(): Return DB_READ_ONLY if innodb_read_only is set.

fts_doc_fetch_by_doc_id(), fts_table_fetch_doc_ids():
Remove the code to start an internal transaction or to roll back,
because this is a read-only operation.

The session object is not really needed for anything.
We can directly create and free the dummy purge_sys->query->trx.

If CREATE TABLE...FULLTEXT INDEX was initiated right before shutdown,
then the function fts_load_stopword() could commit modifications
after shutdown was initiated, causing an assertion failure in
the function trx_purge_add_update_undo_to_history().

Mark as internal all the read/write transactions that
modify fulltext indexes, so that they will be ignored by
the assertion that guards against transaction commits
after shutdown has been initiated.

fts_optimize_free(): Invoke trx_commit_for_mysql() just in case,
because in fts_optimize_create() we started the transaction as
internal, and fts_free_for_backgruond() would assert that the
flag is clear. Transaction commit would clear the flag.

MDEV-14648 Restore fix for MySQL BUG#39053 - UNINSTALL PLUGIN does not allow the storage engine to cleanup open connections

Also, allow the MariaDB 10.2 server to link InnoDB dynamically
against ha_innodb.so (which is what mysql-test-run.pl expects
to exist, instead of the default name ha_innobase.so).

wsrep_load_data_split(): Instead of referring to innodb_hton_ptr,
check the handlerton::db_type. This was recently broken by me in
MDEV-11415.

innodb_lock_schedule_algorithm: Define as a weak global symbol,
so that WITH_WSREP will not depend on InnoDB being linked statically.
I tested this manually. Notably, running a test that only does
	SET GLOBAL wsrep_on=1;
with a static or dynamic InnoDB and
	./mtr --mysqld=--loose-innodb-lock-schedule-algorithm=fcfs
will crash with SIGSEGV at shutdown. With the default VATS
combination the wsrep_on is properly refused for both the
static and dynamic InnoDB.

ha_close_connection(): Do invoke the method also for plugins
for which UNINSTALL PLUGIN was deferred due to open connections.
Thanks to @svoj for pointing this out.

thd_to_trx(): Return a pointer, not a reference to a pointer.

check_trx_exists(): Invoke thd_set_ha_data() for assigning a transaction.

log_write_checkpoint_info(): Remove an unused DEBUG_SYNC point
that would cause an assertion failure on shutdown after deferred
UNINSTALL PLUGIN.

This was tested as follows:

cmake -DWITH_WSREP=1 -DPLUGIN_INNOBASE:STRING=DYNAMIC \
-DWITH_MARIABACKUP:BOOL=OFF ...
make
cd mysql-test
./mtr innodb.innodb_uninstall

fts_cmp_set_sync_doc_id(), fts_load_stopword(): Start the transaction
in read-only mode if innodb_read_only is set.

fts_update_sync_doc_id(), fts_commit_table(), fts_sync(),
fts_optimize_table(): Return DB_READ_ONLY if innodb_read_only is set.

fts_doc_fetch_by_doc_id(), fts_table_fetch_doc_ids():
Remove the code to start an internal transaction or to roll back,
because this is a read-only operation.

Fixes MDEV-14761 "Assertion `!mysql_parse_status || thd->is_error() ||
thd->get_internal_handler()' failed in parse_sql"

The session object is not really needed for anything.
We can directly create and free the dummy purge_sys->query->trx.

If CREATE TABLE...FULLTEXT INDEX was initiated right before shutdown,
then the function fts_load_stopword() could commit modifications
after shutdown was initiated, causing an assertion failure in
the function trx_purge_add_update_undo_to_history().

Mark as internal all the read/write transactions that
modify fulltext indexes, so that they will be ignored by
the assertion that guards against transaction commits
after shutdown has been initiated.

fts_optimize_free(): Invoke trx_commit_for_mysql() just in case,
because in fts_optimize_create() we started the transaction as
internal, and fts_free_for_backgruond() would assert that the
flag is clear. Transaction commit would clear the flag.

MDEV-14648 Restore fix for MySQL BUG#39053 - UNINSTALL PLUGIN does not allow the storage engine to cleanup open connections

Also, allow the MariaDB 10.2 server to link InnoDB dynamically
against ha_innodb.so (which is what mysql-test-run.pl expects
to exist, instead of the default name ha_innobase.so).

wsrep_load_data_split(): Instead of referring to innodb_hton_ptr,
check the handlerton::db_type. This was recently broken by me in
MDEV-11415.

innodb_lock_schedule_algorithm: Define as a weak global symbol,
so that WITH_WSREP will not depend on InnoDB being linked statically.
I tested this manually. Notably, running a test that only does
	SET GLOBAL wsrep_on=1;
with a static or dynamic InnoDB and
	./mtr --mysqld=--loose-innodb-lock-schedule-algorithm=fcfs
will crash with SIGSEGV at shutdown. With the default VATS
combination the wsrep_on is properly refused for both the
static and dynamic InnoDB.

ha_close_connection(): Do invoke the method also for plugins
for which UNINSTALL PLUGIN was deferred due to open connections.
Thanks to @svoj for pointing this out.

thd_to_trx(): Return a pointer, not a reference to a pointer.

check_trx_exists(): Invoke thd_set_ha_data() for assigning a transaction.

log_write_checkpoint_info(): Remove an unused DEBUG_SYNC point
that would cause an assertion failure on shutdown after deferred
UNINSTALL PLUGIN.

This was tested as follows:

cmake -DWITH_WSREP=1 -DPLUGIN_INNOBASE:STRING=DYNAMIC \
-DWITH_MARIABACKUP:BOOL=OFF ...
make
cd mysql-test
./mtr innodb.innodb_uninstall

Tests that are not available in certain configurations, are marked as
Test command : NOT_AVAILABLE in ctest output.

pcre_test_bat does not work without ctest's -C option (--build-config
that was used earlier was wrong).

There were two problems related to the bug report:
1. Item_datetime::get_date() was not implemented.
   So execution went through val_int() followed
   by int-to-datetime or int-to-time conversion.
   This was the reason why the optimizer did not
   work well on data with fractional seconds.
2. Item_datetime::set() did not have a TIME specific code
   to mix months and days to hours after unpack_time().
   This is why the optimizer did not work well with negative
   TIME values, as well as huge time values.

Changes:

1. Overriding Item_datetime::get_date(), to return ltime.
   This fixes the problem N1.
2. Cleanup: Moving pack_time() and unpack_time() from
   sql-common/my_time.c and include/my_time.h to
   sql/sql_time.cc and sql/sql_time.h, as they are not needed
   on the client side.
3. Adding a new "enum_mysql_timestamp_type ts_type" parameter
   to unpack_time() and moving the TIME specific code to mix
   months and days with hours inside unpack_time().
   Adding a new "ts_type" parameter to Item_datetime::set(),
   to pass it from the caller down to unpack_time().
   So now the TIME specific code is automatically called
   from Item_datetime::set(). This fixes the problem N2.
   This change also helped to get rid of duplicate TIME specific code
   from other three places, where mixing month/days to hours
   was done immediately after unpack_time().
   Moving the DATE specific code to zero hhmmssff
   from Item_func_min_max::get_date_native to inside unpack_time(),
   for symmetry.
4. Removing the virtual method in_vector::result_type(),
   adding in_vector::type_handler() instead.
   This helps to get result_type(), field_type(),
   mysql_timestamp_type() of an in_vector easier.
   Passing type_handler()->mysql_timestamp_type() as
   a new parameter to Item_datetime::set() inside
   in_temporal::value_to_item().
5. Cleaup: Removing separate implementations of in_datetime::get_value()
   and in_time::get_value(). Adding a single implementation
   in_temporal::get_value() instead.
   Passing type_handler()->field_type() to get_value_internal().

pkg_config usually comes with Strawberry perl, and tends to find packages
that might work in mingw compilation, but not with MSVC.

Thus disable PKG_CONFIG, otherwise any FIND_PACKAGE() that is using PkgConfig
can find something (like LibXml2 from connect), can potentially find something
that is not going to compile.