This race condition is a regression caused by MDEV-12121.

btr_cur_update_in_place(): Determine block->index!=NULL only once
in order to determine whether an adaptive hash index bucket needs
to be exclusively locked and unlocked.

If we evaluated block->index multiple times, and the adaptive hash
index was disabled before we locked the adaptive hash index, then
we would never release the adaptive hash index bucket latch, which
would eventually lead to InnoDB hanging.

innodb.truncate_inject: Replacement for innodb_zip.wl6501_error_1

Note: unlike MySQL, in some cases TRUNCATE does not return
an error in MariaDB. This should be fixed in the scope of
MDEV-13564 or similar.

MariaDB inherits the MySQL limitation that ALGORITHM=INPLACE cannot
create more than one FULLTEXT INDEX at a time. As part of the MDEV-11369
Instant ADD COLUMN refactoring, MariaDB 10.3.2 accidentally stopped
enforcing the restriction.

Actually, it is a bug in MySQL 5.6 and MariaDB 10.0 that an ALTER TABLE
statement with multiple ADD FULLTEXT INDEX but without explicit
ALGORITHM=INPLACE would return in an error message, rather than
executing the operation with ALGORITHM=COPY.

ha_innobase::check_if_supported_inplace_alter(): Enforce the restriction
on multiple FULLTEXT INDEX.

prepare_inplace_alter_table_dict(): Replace some code with debug
assertions. A "goto error_handled" at this point would result in
another error, because the reference count of ctx->new_table would be 0.

Speed up compilation

Standard C++ headers contribute a lot to compilation time. Avoid algorithm
and sstream in frequently used headers.

commit 3dc3ab1a introduced
Rows_event_tracker, using a mismatch of size_t (the native
register width) and my_off_t (the file offset width, usually
64 bits). Use my_off_t both in member fields and member functions.

This is a regression that was introduced in MySQL 5.7.6 in
https://github.com/mysql/mysql-server/commit/19855664de0245ff24e0753dc82723fc4e2fb7a5

fil_node_open_file(): Use proper 64-bit arithmetics for truncating
size_bytes to a multiple of a file extent size.

- Removed extra set -x -v used for debugging
- Fixed that that gcc version tests works for gcc 7

Server already has HMT_low/HMT_medium.

InnoDB originally skipped the redo logging of PAGE_MAX_TRX_ID changes
until I enabled it in commit e76b873f
that was part of MySQL 5.5.5 already.

Later, when a more complete history of the InnoDB Plugin for MySQL 5.1
(aka branches/zip in the InnoDB subversion repository) and of the
planned-to-be closed-source branches/innodb+ that became the basis of
InnoDB in MySQL 5.5 was pushed to the MySQL source repository, the
change was part of commit 509e761f:

 ------------------------------------------------------------------------
 r5038 | marko | 2009-05-19 22:59:07 +0300 (Tue, 19 May 2009) | 30 lines

 branches/zip: Write PAGE_MAX_TRX_ID to the redo log. Otherwise,
 transactions that are started before the rollback of incomplete
 transactions has finished may have an inconsistent view of the
 secondary indexes.

 dict_index_is_sec_or_ibuf(): Auxiliary function for controlling
 updates and checks of PAGE_MAX_TRX_ID: check whether an index is a
 secondary index or the insert buffer tree.

 page_set_max_trx_id(), page_update_max_trx_id(),
 lock_rec_insert_check_and_lock(),
 lock_sec_rec_modify_check_and_lock(), btr_cur_ins_lock_and_undo(),
 btr_cur_upd_lock_and_undo(): Add the parameter mtr.

 page_set_max_trx_id(): Allow mtr to be NULL.  When mtr==NULL, do not
 attempt to write to the redo log.  This only occurs when creating a
 page or reorganizing a compressed page.  In these cases, the
 PAGE_MAX_TRX_ID will be set correctly during the application of redo
 log records, even though there is no explicit log record about it.

 btr_discard_only_page_on_level(): Preserve PAGE_MAX_TRX_ID.  This
 function should be unreachable, though.

 btr_cur_pessimistic_update(): Update PAGE_MAX_TRX_ID.

 Add some assertions for checking that PAGE_MAX_TRX_ID is set on all
 secondary index leaf pages.

 rb://115 tested by Michael, fixes Issue #211
 ------------------------------------------------------------------------

After this fix, some bogus references to recv_recovery_is_on()
remained. Also, some references could be replaced with
references to index->is_dummy to prepare us for MDEV-14481
(background redo log apply).

This commit does not touch any variable names or any other actual code,
and thus should not in any way affect how the code works.

- Make Rdb_binlog_manager::unpack_value to not have a stack overrun
  when it is reading invalid data (which it currently does as we in
  MariaDB do not store binlog coordinates under BINLOG_INFO_INDEX_NUMBER,
  see comments in MDEV-14892 for details).
- We may need to store these coordinates in the future, so instead of
  removing the call of this function, let's make it work properly for
  all possible inputs.

Problems --------

The slave io thread did not conduct integrity check
for a group of row-based events. Specifically it tolerates missed
terminal block event that must be flagged with STMT_END. Failure to
react on its loss can confuse the applier thread in various ways.
Another potential issue was that there were no check of impossible
second in row Gtid-log-event while the slave io thread is receiving
to be skipped events after reconnect.

Fixes
-----
The slave io thread is made by this patch to track the rows event
STMT_END status.
Whenever at next event reading the IO thread finds out that a preceding
Rows event did not actually had the flag, an
explicit error is issued.

Replication can be resumed after the source of failure is eliminated,
see a provided test.

Note that currently the row-based group integrity check excludes
the compressed version 2 Rows events (which are not generated by MariaDB
master).
Its uncompressed counterpart is manually tested.

The 2nd issue is covered to produce an error in case the io thread
receives a successive Gtid_log_event while it is post-reconnect
skipping.

In CREATE SEQUENCE or CREATE TEMPORARY SEQUENCE, we should not start
an InnoDB transaction for inserting the sequence status record into
the underlying no-rollback table. Because we did this, a debug assertion
failure would fail in START TRANSACTION WITH CONSISTENT SNAPSHOT after
CREATE TEMPORARY SEQUENCE was executed.

row_ins_step(): Do not start the transaction. Let the caller do that.

que_thr_step(): Start the transaction before calling row_ins_step().

row_ins_clust_index_entry(): Skip locking and undo logging for no-rollback
tables, even for temporary no-rollback tables.

row_ins_index_entry(): Allow trx->id==0 for no-rollback tables.

row_insert_for_mysql(): Do not start a transaction for no-rollback tables.

trx reference counter was updated under mutex and read without any
protection. This is both slow and unsafe. Use atomic operations for
reference counter accesses.