Merge branch '10.3' into trunk

rec_get_offsets_func(): Relax a bogus debug assertion.
It would fail when we are operating on a copied prefix
of a node pointer record.

row_log_table_apply_op(): Remove references to dict_table_t::n_vcols.
Virtual column information is no longer being written to the log.

row_log_t: Remove the unused fields n_old_col, n_old_vcol.

MDEV-13723: Server crashes in ha_heap::find_unique_row or Assertion `0' failed in st_select_lex_unit::optimize with INTERSECT

With INTERSECT/EXCEPT fact that subquery item of IN/ALL/ANY was not assigned value does not mean that temporary table used for calculating unit is empty (records could be deleted).

When MySQL 5.7 introduced indexed virtual columns, it introduced
several bugs into the online table-rebuilding ALTER, that is,
the row_log_table_apply() family of functions.

The online_log format that was introduced for online table-rebuilding
ALTER in MySQL 5.6 should be sufficient. Ideally, any indexed virtual
column values would be evaluated based on the log records in the temporary
file. There is no need to log virtual column values.

(For ADD INDEX, that is row_log_apply(), we always must log the values of
the keys, no matter if the columns are virtual.)

Because omitting the virtual column values removes any chance of
row_log_table_apply() working with indexed virtual columns, we
will for now refuse LOCK=NONE in table-rebuilding ALTER operations
when indexes on virtual columns exist. This restriction would be
lifted in MDEV-14341.

innobase_indexed_virtual_exist(): New predicate, to determine if
indexed virtual columns exist in a table definition.

ha_innobase::check_if_supported_inplace_alter(): Refuse online rebuild
if indexed virtual columns exist.

rec_get_converted_size_temp_v(), rec_convert_dtuple_to_temp_v(): Remove.

row_log_table_delete(), row_log_table_update(, row_log_table_insert():
Remove parameters for virtual columns.

trx_undo_read_v_rows(): Remove the col_map parameter.

row_log_table_apply(): Do not deal with virtual columns.

Conflicts:
	mysql-test/r/cte_recursive.result
	mysql-test/r/derived_cond_pushdown.result
	mysql-test/t/cte_recursive.test
	mysql-test/t/derived_cond_pushdown.test
	sql/datadict.cc
	sql/handler.cc

MDEV-14333 Mariabackup --apply-log-only crashes if incomplete transactions with update_undo logs are present

trx_undo_free_prepared(): Relax the assertion for
mariabackup --apply-log-only.

MDEV-14164: Unknown column error when adding aggregate to function in oracle style procedure FOR loop

Make differentiation between pullout for merge and pulout of outer field during exists2in transformation.
In last case the field was outer and so we can safely start from name resolution context of the SELECT where it was pulled.
Old behavior lead to inconsistence between list of tables and outer name resolution context (which skips one SELECT for merge purposes) which creates problem vor name resolution.

Recording mtr.add_suppression("Could not use .*")
instead of mtr.add_suppression("Could not open .*")
in tests:
- binlog_encryption.rpl_binlog_errors
- binlog_encryption.binlog_index

There was a problem in the recent patch for MDEV-10817:
get_date() must "return true" on null_value rather than "return 0"

(forgot to fix Item_sum_hybrid::get_date() after copying and pasting
from Item_sum_hybrid::val_str()).

FlushObserver::flush(): Never discard unwritten changes.
We do not want to risk corrupting the system tablespace
or .ibd files that are not part of a table-rebuilding ALTER.

Ever since MDEV-10813 cleaned up InnoDB use of atomic memory operations
and made buf_block_fix() an atomic operation, some conditions around
buf_block_fix() have been unnecessary.