Problem:
=======
DROP TABLE IF EXISTS was killed. The table still exists on
the master but the DDL was still logged.

Analysis:
=========
During the execution of DROP TABLE command "ha_delete_table" call is invoked
to delete the table. If the query is killed at this point, the kill command
is not handled within the code. This results in two issues.
1) The table which is not dropped also gets written into the binary log.
2) The code continues further upon receiving 'KILL QUERY'.

Fix:
===
Upon receiving the KILL command the query should stop its current execution.
Tables which were successfully dropped prior to KILL command should be
included in the binary log.

If there're multiple row versions in InnoDB, reading one row from PK
may have O(N) complexity and reading from secondary keys may have
O(N^2) complexity.

The problem occurs when there are many pending versions of the same
row, meaning that the primary key is the same, but a secondary key is
different.  The slowdown occurs when the secondary index is
traversed. This patch creates a helper class for the function
row_sel_get_clust_rec_for_mysql() which can remember and re-use
cached_clust_rec & cached_old_vers so that rec_get_offsets() does not
need to be called over and over for the clustered record.

Corrections by Kevin Lewis <kevin.lewis@oracle.com>

MDEV-20341 Unstable innodb.innodb_bug14704286

Removed test that tested the ability of interrupting long query which
is not long anymore.

Enable the rocksdb test suite. It now passes the valgrind tests.

- Include the valgrind suppressions from the FB upstream

- Use HAVE_Valgrind, not HAVE_Purify (like the rest of MariaDB code does)
  The call to DisownData() is now actually disabled under Valgrind

Use DEBUG_SYNC to hang the execution at the interesting point,
and then kill and restart the server externally. This will work
also with Valgrind. DBUG_SUICIDE() causes Valgrind to hang,
and it could also cause uninteresting reports about memory leaks.

While we are at it, let us clean up innodb.innodb_bulk_create_index_debug
so that it will actually test the desired functionality also in future
versions (with instant ADD COLUMN and DROP COLUMN) and avoid
some unnecessary restarts.

We are adding two DEBUG_SYNC points for ALTER TABLE, because there were
none that would be executed right before ha_commit_trans().

Galera threads were not registered to performance schema and
used pthread_create when mysql_thread_create should have been
used.

Added test case to verify current galera performance schema
instrumentation does work.

Test changes only.

Skip the test on big-endian systems.
In MariaDB Server 10.0 and 10.1 (as well as MySQL 5.6),
the implementation of innodb_checksum_algorithm=crc32
wrongly assumes little-endian byte order.

Fix incorrect else that should have been else if.

MDEV-17614 flags INSERT…ON DUPLICATE KEY UPDATE unsafe for statement-based
replication when there are multiple unique indexes. This correctly fixes
something whose attempted fix in MySQL 5.7
in mysql/mysql-server@c93b0d9a972cb6f98fd445f2b69d924350f9128a
caused lock conflicts. That change was reverted in MySQL 5.7.26
in mysql/mysql-server@066b6fdd433aa6673622341f1a2f0a3a20018043
(with a substantial amount of other changes).

In MDEV-17073 we already disabled the unfortunate MySQL change when
statement-based replication was not being used. Now, thanks to MDEV-17614,
we can actually remove the change altogether.

This reverts commit 8a346f31 (MDEV-17073)
and mysql/mysql-server@c93b0d9a972cb6f98fd445f2b69d924350f9128a while
keeping the test cases.

- mysqltest didn't free read_command_buf
- wait_for_slave_param did write different things to the log if valgrind
  was used.
- Table open cache should not write the initial variable value as it
  can depend on the configuration or if valgrind is used
- A variable in GetResult was used uninitalized

... produces "bytes lost" warnings

When rocksdb_validate_update_cf_options() returns an error,
the update won't happen.
Free the copy of the string in this case.

Problem:-
When mysql executes INSERT ON DUPLICATE KEY INSERT, the storage engine checks
if the inserted row would generate a duplicate key error. If yes, it returns
the existing row to mysql, mysql updates it and sends it back to the storage
engine.When the table has more than one unique or primary key, this statement
is sensitive to the order in which the storage engines checks the keys.
Depending on this order, the storage engine may determine different rows
to mysql, and hence mysql can update different rows.The order that the
storage engine checks keys is not deterministic. For example, InnoDB checks
keys in an order that depends on the order in which indexes were added to
the table. The first added index is checked first. So if master and slave
have added indexes in different orders, then slave may go out of sync.

Solution:-
Make INSERT...ON DUPLICATE KEY UPDATE unsafe while using stmt or mixed format
When there is more then one unique key.
Although there is two exception.
  1. Auto Increment key is not counted because Innodb will get gap lock for
    failed Insert and concurrent insert will get a next increment value. But if
    user supplies auto inc value it can be unsafe.
  2. Count only unique keys for which insertion is performed.

So this patch also addresses the bug id #72921

MDEV-17717
Assertion `!table->pos_in_locked_tables' failed in tc_release_table on
flushing RocksDB table under SERIALIZABLE
MDEV-17998
Deadlock and eventual Assertion `!table->pos_in_locked_tables' failed
in tc_release_table on KILL_TIMEOUT
MDEV-19591
Assertion `!table->pos_in_locked_tables' failed in tc_release_table upon
altering table into S3 under lock.

The problem was that thd->open_tables->pos_in_locked_tables was not reset
when alter table failed to reopen a locked table.

- pcretest.c could use macro with side effect
- maria_chk could access freed memory
- Initialized some variables that could be accessed uninitalized
- Fixed compiler warning in my_atomic-t.c

The general reason why innodb redo log file is limited by 512G is that
log_block_convert_lsn_to_no() returns value limited by 1G. But there is no
need to have unique log block numbers in log group. The fix removes 512G
limit and limits log group size by
(uint32_t maximum value) * (minimum page size), which, in turns, can be
removed if fil_io() is no longer used for innodb redo log io.

- The commit ab6dd774 wrongly sets the
condition inside innobase_srv_conc_enter_innodb().  Problem is that
InnoDB makes the thread to sleep indefinitely if it is a replication
slave thread.

Thanks to Sujatha Sivakumar for contributing the replication test case.

Non-owning reference to elements.

Use it as function argument instead of pointer+size pair or instead of
const std::vector<T>.

Do not use it for strings!

More info is here http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines
Or just google about it.

MDEV-18930: Failed CREATE OR REPLACE TEMPORARY not written into binary log makes data on master and slave diverge

Problem:
=======
Failed CREATE OR REPLACE TEMPORARY TABLE statement which dropped the table but
failed at a later stage of creation of temporary table is not written to
binarylog in row based replication. This causes the slave to diverge.

Analysis:
========
CREATE OR REPLACE statements work as shown below.

CREATE OR REPLACE TABLE table_name (a int);
is basically the same as:

DROP TABLE IF EXISTS table_name;
CREATE TABLE table_name (a int);

Hence every CREATE OR REPLACE TABLE command which dropped the table should be
written to binary log, even when following CREATE TABLE part fails. In order
to achieve this, during the execution of CREATE OR REPLACE command, when a
table is dropped 'thd->log_current_statement' flag is set. When table creation
results in an error within 'mysql_create_table' code, the error handling part
looks for this flag. If it is set the failed CREATE OR REPLACE statement is
written into the binary log inspite of error. This ensure that slave doesn't
diverge from the master. In case of row based replication the error handling
code returns very early, if the table is of type temporary. This is done based
on the assumption that temporary tables are not replicated in row based
replication.

It fails to handle the cases where a temporary table was created as part of
statement based replication at an earlier stage and the binary log format was
changed to row because of an unsafe statement. In this case when a CREATE OR
REPLACE statement is executed on this temporary table it will dropped but the
query will not be written to binary log. Hence slave diverges.

Fix:
===
In error handling code check the return status of create table operation. If
it is successful and replication mode is row based and table is of type
temporary then return. Other wise proceed further to the code which checks for
thd->log_current_statement flag and does appropriate logging.

A combination of:
* lots of include'd test files where each has "--source
  include/have_rocksdb.inc"
* for each such occurrence, MTR adds testsuite's arguments into server
  arguments
* which hits some limit on the length of argv array on Windows, causing
  the server to get garbage data in the last argument.

Work around this by commenting out one of the totally redundant
"source include/have_rocksdb.inc" lines.

- Fix the LooseScan code to support storage engines that return
  HA_ERR_END_OF_FILE if the index scan goes out of provided range
  bounds
- Add a DBUG_EXECUTE_IF("force_group_by",...) to allow a test to
  force a LooseScan
- Adjust rocksdb.group_min_max test not to use features not present
  in MariaDB 10.2 (e.g. optimizer_trace.  In MariaDB 10.4 it's present
  but it doesn't meet the  assumptions that the test makes about it
- Adjust the test result file:
  = MariaDB doesn't support "Enhanced Loose Scan" that FB/MySQL has
  = MariaDB has different cost calculations.

Help user distinguish between space ID and page number.