The long semaphore wait appeared to be the caused by the following
pattern in the MTR test:

```
SET DEBUG_SYNC = "now SIGNAL wsrep_after_certification_continue";
SET DEBUG_SYNC = "now SIGNAL signal.wsrep_apply_cb;
```

Raising two signals, one right after another, caused one signal to
overwrite the other, before the signal was consumed by the thread.
This caused one thread to be stuck until the debug sync point would
timeout.

MDEV-21454 Show actual mismatching values in mismatch error messages from row_import::match_table_columns()

Patch by Hartmut Holzgraefe

Analysis:
========
'max_binlog_cache_size' is configured and a huge transaction is executed. When
the transaction specific events size exceeds 'max_binlog_cache_size' the event
cannot be written to the binary log cache and cache write error is raised.
Upon cache write error the statement is rolled back and the transaction cache
should be truncated to a previous statement specific position.  The truncate
operation should reset the cache to earlier valid positions and flush the new
changes. Even though the flush is successful the cache write error is still in
marked state. The truncate code interprets the cache write error as cache flush
failure and returns abruptly without modifying the write cache parameters.
Hence cache is in a invalid state. When a COMMIT statement is executed in this
session it tries to flush the contents of transaction cache to binary log.
Since cache has partial events the cache write operation will report
'writer.remains' assert.

Fix:
===
Binlog truncate function resets the cache to a specified size. As a first step
of truncation, clear the cache write error flag that was raised during earlier
execution. With this new errors that surface during cache truncation can be
clearly identified.

MDEV-18046: Assortment of crashes, assertion failures and ASAN errors in mysql_show_binlog_events

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following assert when ASAN is enabled.

uint32 binlog_get_uncompress_len(const char*):
  Assertion `(buf[0] & 0xe0) == 0x80' failed

Fix:
===
**Part11: Converted debug assert to error handler code**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following ASAN error.

AddressSanitizer: heap-buffer-overflow on address
READ of size 1 at 0x60e00009cf71 thread T28
#0 0x55e37e034ae2 in net_field_length

Fix:
===
**Part10: Avoid reading out of buffer**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following assert when ASAN is enabled.

Query_log_event::Query_log_event(const char*, uint,
    const Format_description_log_event*, Log_event_type):
  Assertion `(pos) + (6) <= (end)' failed

Fix:
===
**Part9: Removed additional DBUG_ASSERT**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following ASAN error

AddressSanitizer: SEGV on unknown address
The signal is caused by a READ memory access.
User_var_log_event::User_var_log_event(char const*, unsigned int,
    Format_description_log_event const*)

Implemented part of upstream patch.
commit: mysql/mysql-server@a3a497ccf7ecacc900551fb1e47ea4078b45c351

Fix:
===
**Part8: added checks to avoid reading out of buffer limits**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following ASAN error
"heap-buffer-overflow on address" and some times it asserts.

Table_map_log_event::Table_map_log_event(const char*, uint,
    const Format_description_log_event*)
Assertion `m_field_metadata_size <= (m_colcnt * 2)' failed.

Fix:
===
**Part7: Avoid reading out of buffer**


Converted debug assert to error handler code.

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following ASAN error

AddressSanitizer: heap-buffer-overflow on address 0x60400002acb8
Load_log_event::copy_log_event(char const*, unsigned long, int,
    Format_description_log_event const*)

Fix:
===
**Part6: Moved the event_len validation to the begin of copy_log_event function**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following ASAN error

AddressSanitizer: heap-buffer-overflow on address
String::append(char const*, unsigned int)
Query_log_event::pack_info(Protocol*)

Fix:
===
**Part5: Added check to catch buffer overflow**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following ASAN error

heap-buffer-overflow within "my_strndup" in Rotate_log_event

my_strndup /mysys/my_malloc.c:254
Rotate_log_event::Rotate_log_event(char const*, unsigned int,
    Format_description_log_event const*)

Fix:
===
**Part4: Improved the check for event_len validation**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following crash when ASAN is enabled.

SEGV on unknown address
in inline_mysql_mutex_destroy
in my_bitmap_free
in Update_rows_log_event::~Update_rows_log_event()

Fix:
===
**Part3: Initialize m_cols_ai.bitmap to NULL**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> reports following assert when ASAN is enabled.

Rows_log_event::Rows_log_event(const char*, uint,
    const Format_description_log_event*):
Assertion `var_header_len >= 2'

Implemented part of upstream patch.
commit: mysql/mysql-server@a3a497ccf7ecacc900551fb1e47ea4078b45c351

Fix:
===
**Part2: Avoid reading out of buffer limits**

Problem:
========
SHOW BINLOG EVENTS FROM <pos> causes a variety of failures, some of which are
listed below. It is not a race condition issue, but there is some
non-determinism in it.

Analysis:
========
"show binlog events from <pos>" code considers the user given position as a
valid event start position. The code starts reading data from this event start
position onwards and tries to map it to a set of known events. Each event has
a specific event structure and asserts have been added to ensure that read
event data satisfies the event specific requirements. When a random position
is supplied to "show binlog events command" the event structure specific
checks will fail and they result in assert.

Fix:
====
The fix is split into different parts. Each part addresses either an ASAN
issue or an assert/crash.

**Part1: Checksum based position validation when checksum is enabled**


Using checksum validate the very first event read at the user specified
position. If there is a checksum mismatch report an appropriate error for the
invalid event.

INNOBASE_ALTER_NOVALIDATE: Remove the set of operations
INNOBASE_ONLINE_CREATE that was accidentally included in the
definition.

In the merge of 82187a12 to 10.3
(in commit eda71979) the flags
were defined correctly.

This bug was caught by the test innodb_zip.index_large_prefix.

By default (innodb_strict_mode=ON), InnoDB attempts to guarantee
at DDL time that any INSERT to the table can succeed.
MDEV-19292 recently revised the "row size too large" check in InnoDB.
The check still is somewhat inaccurate;
that should be addressed in MDEV-20194.

Note: If a table contains multiple long string columns so that each column
is part of a column prefix index, then an UPDATE that attempts to modify
all those columns at once may fail, because the undo log record might
not fit in a single undo log page (of innodb_page_size). In the worst case,
the undo log record would grow by about 3KiB of for each updated column.

The DDL-time check (since the InnoDB Plugin for MySQL 5.1) is optional
in the sense that when the maximum B-tree record size or undo log
record size would be exceeded, the DML operation will fail and the
transaction will be properly rolled back.

create_table_info_t::row_size_is_acceptable(): Add the parameter
'bool strict' so that innodb_strict_mode=ON can be overridden during
TRUNCATE, OPTIMIZE and ALTER TABLE...FORCE (when the storage format
is not changing).

create_table_info_t::create_table(): Perform a sloppy check for
TRUNCATE TABLE (create_fk=false).

prepare_inplace_alter_table_dict(): Perform a sloppy check for
simple operations.

trx_is_strict(): Remove. The function became unused in
commit 98694ab0 (MDEV-20949).

Modify configuration so that all nodes are part of galera cluster
i.e. wsrep_on=ON. Add missing wait conditions.

test changes only.

Features:
* STL-like interface
* Fast modification: no branches on insertion or deletion
* Fast iteration: one pointer dereference and one pointer comparison
* Your class can be a part of several lists

Modeled after std::list<T> but currently has fewer methods (not complete yet)

For even more performance it's possible to customize list with templates so
it won't have size counter variable or won't NULLify unlinked node.

How existing lists differ?

No existing lists support STL-like interface.

I_List:
* slower iteration (one more branch on iteration)
* element can't be a part of two lists simultaneously

I_P_List:
* slower modification (branches, except for the fastest push_back() case)
* slower iteration (one more branch on iteration)

UT_LIST_BASE_NODE_T:
* slower modification (branches)

Three UT_LISTs were replaced: two in fil_system_t and one in dyn_buf_t.

Moved to the next problematic year (2038).

Modify configuration so that all nodes are part of galera cluster
i.e. wsrep_on=ON.

For Item_direct_view_ref , get value from val_* methods
instead of result* family
The val_* methods gets value from the item on which it is referred.

The 8 bytes at FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION
will be overwritten at page flush, in buf_page_encrypt_before_write(),
ever since commit 765a4360
(MariaDB 10.1.23, 10.2.6, 10.3.1).

btr_store_big_rec_extern_fields(): Remove useless writes to the
page header (and to the redo log) for ROW_FORMAT=COMPRESSED BLOB pages.

The function was only called by innobase_drop_tablespace(),
which was removed in commit 494e4b99
and added in commit 2e814d47.

MDEV-19680:: Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index) || (!(ptr >= table->record[0] && ptr < table->record[0] + table->s->reclength)))' or alike failed upon SELECT with mix of functions from simple view

Set read_set bitmap for view from the JOIN::all_fields list instead of JOIN::fields_list
as split_sum_func would have added items to the all_fields list.

The issue here is for degenerate joins we should execute the window
function but it is not getting executed in all the cases.

To get the window function values window function needs to be executed
always. This currently does not happen in few cases
where the join would return 0 or 1 row like
  1) IMPOSSIBLE WHERE
  2) MIN/MAX optimization
  3) EMPTY CONST TABLE

The fix is to make sure that window functions get executed
and the temporary table is setup for the execution of window functions

innodb.cmake: restrict -fno-builtin-memcmp for GCC versions older that 4.6
where optimization issue was solved.

MDEV-21189 : Dropping partition with 'wsrep_OSU_method=RSU' and 'SESSION sql_log_bin = 0' cases the galera node to hang

Test cleanup. Best practice for using RSU, is to isolate the node
up-front, so this test did not reflect real world scenario

- post-push to fix the compilation issue

- Moved the recv_sys->heap memory condition inside recv_parse_log_recs().
So that, InnoDB can mark the status as STORE_NO earlier.

- InnoDB uses one third of buffer pool chunk size for reading the redo
log records. In that case, we can avoid the scenario where buffer ran
out of memory issue during recovery.