dict_drop_index_tree(): Even if SYS_INDEXES.PAGE contains the
special value FIL_NULL, the tablespace identified by SYS_INDEXES.SPACE
may exist and may need to be dropped. This would definitely be the case
if the server had been killed right after a FILE_CREATE record was
persistently written during CREATE TABLE, but before the transaction
was committed.

btr_free_if_exists(): Simplify the interface, to avoid repeated
tablespace lookup.

One more scenario is known to be broken: If the server is killed
during DROP TABLE (or table-rebuilding ALTER TABLE) right after a
FILE_DELETE record has been persistently written but before the
file was deleted, then we could end up recovering no tablespace
at all, and failing to delete the file, in either of fil_name_process()
or dict_drop_index_tree().

Thanks to Elena Stepanova for providing "rr replay" and data directories
of these scenarios.

Make DDL operations that involve FULLTEXT INDEX atomic.
In particular, we must drop the internal FTS_ tables in the same
DDL transaction with ALTER TABLE.

Remove all references to fts_drop_orphaned_tables().

row_merge_drop_temp_indexes(): Drop also the internal FTS_ tables
that are associated with index stubs that were created in
prepare_inplace_alter_table_dict() for
CREATE FULLTEXT INDEX before the server was killed.

fts_clear_all(): Remove the fts_drop_tables() call. It has to be
executed before the transaction is committed!

dict_load_indexes(): Do not load any metadata for index stubs
that had been created by prepare_inplace_alter_table_dict()

fts_create_one_common_table(), fts_create_common_tables(),
fts_create_one_index_table(), fts_create_index_tables():
Remove redundant error handling. The tables will be dropped
just fine by dict_drop_index_tree().

commit_try_norebuild(): Also drop the FTS_ tables when dropping
FULLTEXT INDEX.

The changes to the test case innodb_fts.crash_recovery has been
extensively tested. The non-debug server will be killed while
the 3 ALTER TABLE are in any phase of execution. With the debug
server, DEBUG_SYNC should make the test deterministic.

The test innodb.doublewrite could occasionally fail with 64KiB page size
because the page 0 would no longer be in the doublewrite buffer.
Let us stop purge before the server is killed, and ensure that
the entire buffer pool will be flushed before we initiate an extra
write of page 0.

galera_var_wsrep_on_off : Add wait conditions to make sure DDL is
replicated before continuing.

wsrep.[variables|variables_debug] :  Remove unnecessary parts
and add check to correct number of variables or skip

galera_ssl_reload: Add version check and SSL checks.

Fixed NULL pointer reference to db.str

Keep the readline installation step in Salsa-CI stages that install
MariaDB.org packages in Debian Sid (or releases after is, such as
Debian 11 "Bullseye" or Ubuntu 21.04 "Hirsute") as those old packages
still depend on readline for the MariaDB Server itself.

Problem:
=======
Test assertion fails on slave.

Assertion text: 'Last_Seen_Transaction should show .'
Assertion condition: '"0-1-1" = ""'
Assertion condition, interpolated: '"0-1-1" = ""'
Assertion result: '0'

Analysis:
========
Test case creates a table on master and it waits for it to be replicated to
slave and applied by slave applier. On completion 'Last_Seen_Transaction'
value from 'performance_schema.replication_applier_status_by_worker' table
is compared with '@@gtid_slave_pos' to ensure its correctness. The test
should ensure that user table and 'gtid_slave_pos' table are of same engine
type 'InnoDB' to get consistent test results. This guarantees that
'gtid_slave_pos' table is updated as part of transaction commit. In the of
such an engine consistency, user table gets created in default MyISAM
storage engine and 'mysql.gtid_slave_pos' table gets created in Aria
storage engine. When the test code reaches above assert there might be a
delay in an update to 'gtid_slave_pos' table, which leads to test assertion
failure.

Fix:
===
Use InnoDB engine for both user table and 'mysql.gtid_slave_pos' table.

Before we create an InnoDB data file, we must have persistently
started a DDL transaction and written a record in SYS_INDEXES
as well as a FILE_CREATE record for creating the file.
In that way, if InnoDB is killed before the DDL transaction is
committed, the rollback will be able to delete the file in
dict_drop_index_tree().

dict_build_table_def_step(): Do not create the tablespace.
At this point, we have not written any log, not even for
inserting the SYS_TABLES record.

dict_create_sys_indexes_tuple(): Relax an assertion to tolerate
a missing tablespace before the first index has been created in
dict_create_index_step().

dict_build_index_def_step(): Relax the dict_table_open_on_name()
parameter, because no tablespace may be available yet.

tab_create_graph_create(), row_create_table_for_mysql(), tab_node_t:
Remove key_id, mode.

ind_create_graph_create(), row_create_index_for_mysql(), ind_node_t:
Add key_id, mode.

dict_create_index_space(): New function, to create the tablespace
during clustered index creation.

dict_create_index_step(): After the SYS_INDEXES record has been
written, invoke dict_create_index_space() to create the tablespace
if needed.

fil_ibd_create(): Before creating the file, persistently write a
FILE_CREATE record. This will also ensure that an incomplete DDL
transaction will be recovered. After creating the file, invoke
fsp_header_init().

InnoDB used to support at most one CREATE TABLE or DROP TABLE
per transaction. This caused complications for DDL operations on
partitioned tables (where each partition is treated as a separate
table by InnoDB) and FULLTEXT INDEX (where each index is maintained
in a number of internal InnoDB tables).

dict_drop_index_tree(): Extend the MDEV-24589 logic and treat
the purge or rollback of SYS_INDEXES records of clustered indexes
specially: by dropping the tablespace if it exists. This is the only
form of recovery that we will need.

trx_undo_ddl_type: Document the DDL undo log record types better.

trx_t::dict_operation: Change the type to bool.

trx_t::ddl: Remove.

trx_t::table_id, trx_undo_t::table_id: Remove.

dict_build_table_def_step(): Remove trx_t::table_id logging.

dict_table_close_and_drop(), row_merge_drop_table(): Remove.

row_merge_lock_table(): Merged to the only callers, which can
call lock_table_for_trx() directly.

fts_aux_table_t, fts_aux_id, fts_space_set_t: Remove.

fts_drop_orphaned_tables(): Remove.

row_merge_rename_index_to_drop(): Remove. Thanks to MDEV-24589,
we can simply delete the to-be-dropped indexes from SYS_INDEXES,
while still being able to roll back the operation.

ha_innobase_inplace_ctx: Make a few data members const.
Preallocate trx.

prepare_inplace_alter_table_dict(): Simplify the logic. Let the
normal rollback take care of some cleanup.

row_undo_ins_remove_clust_rec(): Simplify the parsing of SYS_COLUMNS.

trx_rollback_active(): Remove the special DROP TABLE logic.

trx_undo_mem_create_at_db_start(), trx_undo_reuse_cached():
Always write TRX_UNDO_TABLE_ID as 0.

galera_var_wsrep_on_off : Add wait conditions to make sure DDL is
replicated before continuing.

wsrep.[variables|variables_debug] :  Remove unnecessary parts
and add check to correct number of variables or skip

galera_ssl_reload: Add version check and SSL checks.

                after previous error upon multi-RENAME

- InnoDB fails to rename the foreign key constraint while
rollbacking the rename operation. In that case, InnoDB should
rename the FK constraint too.

This happens during repair when a temporary table is opened
with HA_OPEN_COPY, which resets 'share->born_transactional', which
the encryption code did not like.

Fixed by resetting just share->now_transactional.

MDEV-22265 Connect string character limit too small for full 64 character InnoDB table-name limit when using ad-hoc Spider server definitions.

Fix length for getting default table name.

xdes_get_descriptor_with_space_hdr(): Use the correct mode
BUF_GET_POSSIBLY_FREED also when the tablespace is larger
than innodb_page_size pages. This function could be called by
fseg_free_step().

fsp_alloc_seg_inode(): For completeness (and for improved robustness
in case of a corrupted tablespace), use BUF_GET_POSSIBLY_FREED.
With this, the entire compilation unit fsp0fsp.cc will use that mode.

make os_file_rename_func work on Windows the same as on Unix.

In commit 54e2e701
we relaxed a debug assertion in the POSIX version of
os_file_rename_func() only. Let us relax it also on Windows,
so that the test innodb.truncate_crash will pass.

In commit 91599701 (MDEV-25312)
some recovery code for TRUNCATE TABLE was broken
causing a regression in a case where undo log for a RENAME TABLE
operation had been durably written but the tablespace had not been
renamed yet.

row_rename_table_for_mysql(): Add a DEBUG_SYNC point for the
test case, and simplify the logic and trim the error messages.

fil_space_t::rename(): Simplify the operation. Merge the necessary
part of fil_rename_tablespace_check(). If there is no change to
the file name, do nothing.

dict_table_t::rename_tablespace(): Refactored from
dict_table_rename_in_cache().

row_undo_ins_parse_undo_rec(): On rolling back TRX_UNDO_RENAME_TABLE,
invoke dict_table_t::rename_tablespace() even if the table name matches.

os_file_rename_func(): Temporarily relax an assertion that would
fail during the recovery in the test innodb.truncate_crash.

MDEV-25530 Error 1451 on slave: Cannot delete or update a parent row: a foreign key constraint fails

after dfb41fdd tables that failed to drop are excluded from the
binlogged DROP TABLE statement. It means that the slave should not
expect any errors when executing DROP TABLE, and the binlog should
report that no error has happened, even if it was.

Do not write error code into the binlogged DROP TABLE,
and remove all code that was needed to compute it.

MDEV-22265 Connect string character limit too small for full 64 character InnoDB table-name limit when using ad-hoc Spider server definitions.

Fix length for getting default table name.

Cluster communication should be possible even when:

1. Node 2 is TCP
2. Node 1/3 is dynamic with SSL enabled

During test we shutdown Node 2 and enable SSL on it. It should connect
back to cluster successfully.

The assert is no more reproducible in the lastest 10.5-10.6

The patch only adds testcase from MDEV-24382.

ha_innobase::start_stmt(): Always set m_prebuilt->sql_stat_start.

row_search_mvcc(): Cleanup: Simplify debug assertions.

lock_discard_for_index(): New function, to discard locks for an
index whose index tree has been purged. By definition, such indexes
must be ones for which the MDL upgrade failed in inplace ALTER TABLE
and the ADD INDEX operation was never committed.
Note: Because we do not support online ADD SPATIAL INDEX, we only
have to traverse the lock_sys.rec_hash for B-trees and not the
hash tables for R-trees.

row_purge_remove_clust_if_poss_low(): Invoke lock_discard_for_index()
if necessary before dropping a B-tree for a SYS_INDEXES record.

btr_free_if_exists(): Always use the BUF_GET_POSSIBLY_FREED mode
when accessing pages, because due to MDEV-24589 the function
fil_space_t::set_stopping(true) can be called at any time during
the execution of this function.

mtr_t::m_freeing_tree: New data member for debugging purposes.

buf_page_get_low(): Assert that the BUF_GET mode is not being used
anywhere during the execution of btr_free_if_exists().

In all code related to freeing or allocating pages, we will add some
robustness, by making more use of BUF_GET_POSSIBLY_FREED and by
reporting an error instead of crashing in some cases of corruption.

fil_check_pending_ops(), fil_check_pending_io(): Remove.
These functions were actually duplicating each other ever since
commit 118e258a (MDEV-23855).

fil_space_t::check_pending_operations(): Replaces
fil_check_pending_operations() and incorporates the logic of
fil_check_pending_ops(). Avoid unnecessary lookups for the tablespace.
Just wait for the reference count to drop to zero.

fil_space_t::io(): Remove an unnecessary condition. We can (and
probably better should) refuse asynchronous reads of undo tablespaces
that are being truncated.

fil_truncate_prepare(): Remove.

trx_purge_truncate_history(): Implement the necessary steps that used
to be in fil_truncate_prepare().

            innodb_adaptive_flushing_lwm is hit. (possible regression)

adaptive flushing should kick in if
a. dirty_pct (dirty pages in buffer pool) > innodb_max_dirty_pages_pct_lwm
OR
b. innodb_adaptive_flushing_lwm limit is reached (default to 10%)

both conditions are mutually exclusive and whichever is first to evaluate
true should kick-start the adaptive flushing.

After recent changes to simplify the flushing algorithm logic, (b) got ignored
that introduced the said regression.