The warning was originally added in
commit c6766305
(MySQL 4.1.12, 5.0.3) to trace claimed undo log corruption that
was analyzed in https://lists.mysql.com/mysql/176250
on November 9, 2004.

Originally, the limit was 20,000 undo log headers or transactions,
but in commit 9d6d1902
in MySQL 5.5.11 it was increased to 2,000,000.

The message can be triggered when the progress of purge is prevented
by a long-running transaction (or just an idle transaction whose
read view was started a long time ago), by running many transactions
that UPDATE or DELETE some records, then starting another transaction
with a read view, and finally by executing more than 2,000,000
transactions that UPDATE or DELETE records in InnoDB tables. Finally,
when the oldest long-running transaction is completed, purge would
run up to the next-oldest transaction, and there would still be more
than 2,000,000 transactions to purge.

Because the message can be triggered when the database is obviously
not corrupted, it should be removed. Heavy users of InnoDB should be
monitoring the "History list length" in SHOW ENGINE INNODB STATUS;
there is no need to spam the error log.

- Skip 'clean' if not a git repository
  (Good for tar files)
- Add configuration for ASAN builds

Roll back to most general duplicate removing strategi in case of different stratagies for one position.

Replace most occurrences of the REFMAN macro. For some pages there
is no replacement yet.

recv_log_recover_10_3(): Determine if a log from MariaDB 10.3 is clean.

recv_find_max_checkpoint(): Allow startup with a clean 10.3 redo log.

srv_prepare_to_delete_redo_log_files(): When starting up with a 10.3 log,
display a "Downgrading redo log" message instead of "Upgrading".

Backport the fix from 10.0.33 to 5.5, in case someone compiles XtraDB
with -DUNIV_LOG_ARCHIVE

The XtraDB option innodb_track_changed_pages causes
the function log_group_read_log_seg() to be invoked
even when recv_sys==NULL, leading to the SIGSEGV.

This regression was caused by
MDEV-11027 InnoDB log recovery is too noisy

is set to ERR

This matches gcc/clang handling.

with recursive reference in subquery

If a recursive CTE uses a subquery with recursive reference then
the virtual function reset() must be called after each iteration
performed at the execution of the CTE.

innodb/buf_LRU_get_free_block
	Add debug instrumentation to produce error message about
	no free pages. Print error message only once and do not
	enable innodb monitor.

xtradb/buf_LRU_get_free_block
	Add debug instrumentation to produce error message about
	no free pages. Print error message only once and do not
	enable innodb monitor. Remove code that does not seem to
	be used.

innodb-lru-force-no-free-page.test
	New test case to force produce desired error message.

row_insert_for_mysql(): Remove some duplicated code

dict_foreign_find_index(): Ignore incompletely created indexes.
After a failed ADD UNIQUE INDEX, an incompletely created index
could be left behind until the next ALTER TABLE statement.

recv_parse_or_apply_log_rec_body(): Tolerate MLOG_4BYTES for
dummy-writing the FIL_PAGE_SPACE_ID, written by fil_crypt_rotate_page().

rec_get_trx_id(): Because rec is not necessarily residing in
a buffer pool page (it could be an old version of a clustered index
record, allocated from heap), remove the debug assertions that
depend on page_align(rec).

There is a race condition on a test. con1 is the older transaction
as it query started wait first. Test continues so that con1 gets
lock wait timeout first. There is possibility that default connection
gets lock timeout also or as con1 is rolled back it gets the locks
it waited and does the update. Fixed by removing query outputs as
they could vary and accepting success from default connection
query.

This bug affects both writing and reading encrypted redo log in
MariaDB 10.1, starting from version 10.1.3 which added support for
innodb_encrypt_log. That is, InnoDB crash recovery and Mariabackup
will sometimes fail when innodb_encrypt_log is used.

MariaDB 10.2 or Mariabackup 10.2 or later versions are not affected.

log_block_get_start_lsn(): Remove. This function would cause trouble if
a log segment that is being read is crossing a 32-bit boundary of the LSN,
because this function does not allow the most significant 32 bits of the
LSN to change.

log_blocks_crypt(), log_encrypt_before_write(), log_decrypt_after_read():
Add the parameter "lsn" for the start LSN of the block.

log_blocks_encrypt(): Remove (unused function).

using VIEW and WITH RECURSIVE.

The cause of this crash was the same as of the crash reported in mdev-14755.

2cd31691 broke conf_to_src,
because strings library is now dependend on mysys (my_alloc etc are used
now directly in string lib)

Fix by adding appropriate dependency.

Also exclude conf_to_src from VS IDE builds. EXCLUDE_FROM_ALL
is not enough for that.

with condition_pushdown_for_derived=on

This bug is a consequence of the bug mdev-14368 fixed in 5.5.59.

If the specification of a CTE contains a reference to a temporary table
then THD::open_temporary_table() must be called for this reference for
any occurrence of the CTE in the query. By mistake this was done only
for the first occurrences of CTEs.
The patch fixes this problem in With_element::clone_parsed_spec().
It also moves there the call of check_dependencies_in_with_clauses()
to its proper place before the call of check_table_access().
Additionally the patch optimizes the number of calls of the
function check_dependencies_in_with_clauses().

row_sel_get_clust_rec_for_mysql(): Look up the page from the
buffer pool, similar to how MySQL 5.7 does it.

debug_key_management
encrypt_and_grep
innodb_encryption

If real table count is different from what is expected by the test, it
just hangs on waiting to fulfill hardcoded number. And then exits with
**failed** after 10 minutes of wait: quite unfriendly and hard to
figure out what's going on.