&sys_buf + DATA_TRX_ID_LEN is not &(sys_buf + DATA_TRX_ID_LEN).

create_table_def(), ha_innobase::create(): Defer fts_optimize_add_table()
until after the table has been successfully created.

row_fts_merge_insert(): Correctly initialize DB_ROLL_PTR to a safe value
that will not be dereferenced by MVCC.

merge_role_db_privileges() was remembering pointers into Dynamic_array
acl_dbs, and later was using them, while pushing more elements into the
array. But pushing can cause realloc, and it can invalidate all pointers.

Fix: remember and use indexes of elements, not pointers.

MDEV-17432 Assertion `lock_trx_has_sys_table_locks(trx) == 0' failed upon ALTER TABLE .. ADD FOREIGN KEY

- Fixed innodb.table_flags test case in release build.

MDEV-17432 Assertion `lock_trx_has_sys_table_locks(trx) == 0' failed upon ALTER TABLE .. ADD FOREIGN KEY

- This is a regression of commit b26e603a. While dropping
the incompletely created table, InnoDB shouldn't consider that operation as non-atomic one.

When the with clause of a query contains a recursive CTE that is not used
then processing of EXPLAIN for this query does not require optimization
of the unit specifying this CTE. In this case if 'derived' is the
TABLE_LIST object created for this CTE then derived->derived_result is NULL
and any assignment to derived->derived_result->table causes a crash.
After fixing this problem in the code of st_select_lex_unit::prepare()
EXPLAIN for such a query worked without crashes. Yet an execution
plan for the recursive CTE appeared there. The cause of this problem was
an incorrect condition used in JOIN::save_explain_data_intern() that
determined whether CTE was to be optimized or not. A similar condition was
used in select_describe() and this patch has corrected it as well.

In 10.3, rec_is_metadata() takes a pointer, while in 10.4 it
takes a reference as a parameter. I ported this patch from
10.4 to 10.3, and then only ran a release build, not debug build.

The special flag REC_INFO_MIN_REC_FLAG used to be only set on the
first record in the leftmost node pointer page of each level of the tree.
It was never set on leaf pages.

MDEV-11369 Instant ADD COLUMN in MariaDB Server 10.3 repurposed the flag
to identify a hidden metadata record, which is stored in the first record
on the leftmost leaf page.

If the adaptive hash index points to records in the leftmost leaf page
after instant ALTER TABLE, we would have such a metadata record in the
table, an assertion could fail when trying to validate the index record.
In a release build, we might wrongly qualify the hidden metadata record
and thus return garbage results.

cmp_dtuple_rec_with_match_bytes(): If the REC_INFO_MIN_REC_FLAG is
set on the record, assert that this is the first record on the
leftmost page and that the record is a metadata record, and finally
return 1, because by definition, anything is greater than the
minimum record.

Also, related to MDEV-15522, MDEV-17304, MDEV-17835,
remove the Galera xtrabackup tests, because xtrabackup never worked
with MariaDB Server 10.3 due to InnoDB redo log format changes.

Disable tests that do not yet pass.

MDEV-17810: Improve error printout when decryption fails or we identify page as both encrypted and unencrypted

fil_space_verify_crypt_checksum
	Print out both stored checksum and calculated checksums
	for encrypted page and unencrypted page asumptions.

dict_create_add_foreigns_to_dictionary(): Do not commit the transaction.
The operation can still fail in dict_load_foreigns(), and we want
to be able to roll back the transaction.

create_table_info_t::create_table(): Never reset m_drop_before_rollback,
and never commit the transaction. We use a single point of rollback
in ha_innobase::create(). Merge the logic from
row_table_add_foreign_constraints().

This is a regression due to MDEV-17816.

When creating a table fails, we must roll back the dictionary
transaction. Because the rollback may rename tables, and because
InnoDB lacks proper undo logging for CREATE operations, we must
drop the incompletely created table before rolling back the
transaction, which could include a RENAME operation.
But, we must not blindly drop the table by name; after all,
the operation could have failed because another table by the
same name already existed.

create_table_info_t::m_drop_before_rollback: A flag that is set
if the table needs to be dropped before transaction rollback.

create_table_info_t::create_table(): Remove some duplicated
error handling.

ha_innobase::create(): On error, only drop the table if it was
actually created.

Added a testcase

The code became unused in commit 10590dd3.

Add check that file key management plugin is found.

fil_space_t::add(): Replaces fil_node_create(), fil_node_create_low().
Let the caller pass fil_node_t::handle, to avoid having to close and
re-open files.

fil_node_t::read_page0(): Refactored from fil_node_open_file().
Read the first page of a data file.

fil_node_open_file(): Open the file only once.

srv_undo_tablespace_open(): Set the file handle for the opened
undo tablespace. This should ensure that ut_ad(file->is_open())
no longer fails in recv_add_trim().

xtrabackup_backup_func(): Remove some dead code.

xb_fil_cur_open(): Open files only if needed. Undo tablespaces
should already have been opened.

trx_assign_rseg_low(): Skip dedicated undo tablespaces if
innodb_undo_tablespaces=0 has been set after the database was created.

When dropping a partially created table due to failure,
use SQLCOM_TRUNCATE instead of SQLCOM_DROP_DB, so that
no foreign key constraints will be touched. If any
constraints were added as part of the creation, they would
be reverted as part of the transaction rollback.

We need an explicit call to row_drop_table_for_mysql(),
because InnoDB does not do proper undo logging for CREATE TABLE,
but would only drop the table at the end of the rollback.
This would not work if the transaction combines both
RENAME and CREATE, like TRUNCATE now does.