* ignore CHECK constraint for historical rows;
* FOREIGN KEY test case.

TODO:
MDEV-16301 IB: use real table name for error messages on ALTER

Closes tempesta-tech/mariadb#491
Closes #748

MDEV-15947 ASAN heap-use-after-free in Item_ident::print or in my_strcasecmp_utf8 or unexpected ER_BAD_FIELD_ERROR upon call of stored procedure reading from versioned table

Closes #728

MDEV-15645 Assertion `table->insert_values' failed in write_record upon REPLACE into a view with underlying versioned table

Right temporary storage for system versioning operations is table->record[2],
not table->insert_values

Closes #712

RBR not versioned -> versioned

do it for all write_row events, not only for WRITE_ROWS_EVENT_V1

Use GetLastError() instead.

table->in_use is not always set and a KILL signal can arrive anytime.

MDEV-7257 made a dump thread to read from binlog concurrently with
writers as long as the read bytes are below a water-mark
(MYSQL_BIN_LOG::binlog_end_pos). However it appeared to be possible a
dump thread reader reach out for bytes past the water mark through a
feature of IO_CACHE that fills in the internal buffer and while doing
so it could read what the reader is not supposed to see (the bytes
above MYSQL_BIN_LOG::binlog_end_pos).

The issue is fixed with constraining the IO_CACHE buffer fill to respect
the watermark.

An added unit test proves reading from file is bound to an external
parameter
passed to {IO_CACHE::end_of_file} cache member.

Problem:

push_handler() created sp_handler_entry instances on THD::main_mem_root,
which is freed only after the SP instructions execution.
So in case of a CONTINUE HANDLER inside a loop (e.g. WHILE) this approach
leaked thread memory on every loop iteration.

Changes:
- Removing sp_handler_entry declaration, it's not really needed.
- Fixing the data type of sp_rcontext::m_handlers from
  Dynamic_array<sp_handler_entry*> to Dynamic_array<sp_instr_hpush_jump*>
- Fixing sp_rcontext::push_handler() to push the pointer to
  an sp_instr_hpush_jump instance to the handler stack.
  This instance contains everything we need.
  There is no a need to allocate anything else.

rnd_pos_by_record calls ha_rnd_pos, which does the counting

MDEV-7257 made a dump thread to read from binlog concurrently with
writers as long as the read bytes are below a water-mark
(MYSQL_BIN_LOG::binlog_end_pos). However it appeared to be possible a
dump thread reader reach out for bytes past the water mark through a
feature of IO_CACHE that fills in the internal buffer and while doing
so it could read what the reader is not supposed to see (the bytes
above MYSQL_BIN_LOG::binlog_end_pos).

The issue is fixed with constraining the IO_CACHE buffer fill to respect
the watermark.

An added unit test proves reading from file is bound to an external
parameter
passed to {IO_CACHE::end_of_file} cache member.

Different fix, just use NULL, not no_db,

The previous correction of the patch for mdev-16473 did not work
correctly for the databases whose names started with '*'.
Added a test case with a database named "*".

Only close stdin if it was open initinally. Otherwise we may close file
descriptor which is reused for different puprose (specifically for binlog
index file in case of this bug).

This is a typical systemd response where it tries to shutdown the
joiner (due to "timeout") before the joiner manages to complete SST.

wsrep_sst_wait
wsrep_SE_init_wait
	While waiting the operation to finish use mysql_cond_timedwait
	instead of mysql_cond_wait and if operation is not finished
	extend systemd timeout (if needed).

Problem:

push_cursor() created sp_cursor instances on THD::main_mem_root,
which is freed only after the SP instructions loop.

Changes:
- Moving sp_cursor declaration from sp_rcontext.h to sql_class.h
- Deriving sp_instr_cpush from sp_cursor. So now sp_cursor is created
  only once (at the SP parse time) and then reused on all loop iterations
- Adding a new method reset() into sp_cursor (and its parent classes)
  to reset an sp_cursor instance before reuse.
- Moving former sp_cursor members m_fetch_count, m_row_count, m_found
  into a separate class sp_cursor_statistics. This helps to reuse
  the code in sp_cursor constructors, and in sp_cursor::reset()
- Adding a helper method sp_rcontext::pop_cursor().
- Adding "THD*" parameter to so_rcontext::pop_cursors() and pop_all_cursors()
- Removing "new" and "delete" from sp_rcontext::push_cursor() and
  sp_rconext::pop_cursor().
- Fixing sp_cursor not to derive from Sql_alloc, as it's now allocated
  only as a part of sp_instr_cpush (and not allocated separately).
- Moving lex_keeper->disable_query_cache() from sp_cursor::sp_cursor()
  to sp_instr_cpush::execute().
- Adding tests

	NULL values when there is no DEFAULT

- Fixed the test failure, assigned number of rows read to new table.

dict0dict.cc

buf_LRU_drop_page_hash_for_tablespace(): Return whether any adaptive
hash index entries existed. If yes, the caller should keep retrying to
drop the adaptive hash index.

row_import_for_mysql(), row_truncate_table_for_mysql(),
row_drop_table_for_mysql(): Ensure that the adaptive hash index was
entirely dropped for the table.

MDEV-15953 Alter InnoDB Partitioned Table Moves Files (which were originally not in the datadir) to the datadir

ha_innobase::prepare_inplace_alter_table: preserve DATA DICTIONARY for table

Before this patch if no default database was set the server threw
an error for any table name reference that was not fully qualified by
database name. In particular it happened for table names referenced
CTE tables. This was incorrect.
The error message was thrown at the parser stage when the names referencing
different tables were not resolved yet.
Now if no default database is set and  a with clause is used in the
processed statement  any table reference is just supplied with a dummy
database name "*none*" at the parser stage. Later after a call
of check_dependencies_in_with_clauses() when the names for CTE tables
can be resolved error messages are thrown only for those names that
refer to non-CTE tables. This is done in open_and_process_table().

register changes of last_gtid

  MDEV-10581 sql_mode=ORACLE: Explicit cursor FOR LOOP
  MDEV-12098 sql_mode=ORACLE: Implicit cursor FOR loop

Cleanup changes:
- Removing sp_lex_cursor::m_cursor_name
- Adding sp_instr_cursor_copy_struct::m_cursor (the cursor global index)
- Fixing sp_instr_cursor_copy_struct::print() to access to the cursor
  name using m_ctx and m_cursor (like other cursor related instructions do)
  instead of m_cursor_name.

This change is needed to unify sp_assignment_lex and sp_cursor_lex later,
to fix this problem easier:
 MDEV-16558 Parenthesized expression does not work as a lower FOR loop bound

	NULL values when there is no DEFAULT

- Fixed typecasting failure for log->n_rows in row0log.cc