MDEV-13073. This patch is a followup of the previous one to convert the trailing underscore identifier to mariadb standard. For identifier representing class private members the underscore is replaced with a `m_` prefix. Otherwise `_` is just removed.

MDEV-13073. This part converts the Ali patch`s identifiers to the MariaDB standard. Also some renaming is done as well as white spaces removal.

and its custom trace faciltiy with standard DBUG_ based equivalents.

one) and affected result files.

Specifically to rpl_semi_sync_after_sync*, the changed results reflect
a fact that thanks to fixes in the dump thread functionality
there's no longer zombie thread to kill neither such thread represent
a semisync client (so the counter drops).

is defined statically. Consequently the observer interfaces are removed
as well.

and specifically the ack receiving functionality.
Semisync is turned to be static instead of plugin so its functions
are invoked at the same points as RUN_HOOKS.
The RUN_HOOKS and the observer interface remain to be removed by later
patch.

Todo:
  React on killed status by repl_semisync_master.wait_after_sync(). Currently
  Repl_semi_sync_master::commit_trx does not check the killed status.

  There were few bugfixes found that are present in mysql and its unclear
  whether/how they are covered. Those include:

  Bug#15985893: GTID SKIPPED EVENTS ON MASTER CAUSE SEMI SYNC TIME-OUTS
  Bug#17932935 CALLING IS_SEMI_SYNC_SLAVE() IN EACH FUNCTION CALL
                 HAS BAD PERFORMANCE
  Bug#20574628: SEMI-SYNC REPLICATION PERFORMANCE DEGRADES WITH A HIGH NUMBER OF THREADS

RUN_HOOK() is only called if semisync is enabled

As the server can't disable the hooks if something is in progress, I added
a new variable, run_hooks_enabled, that is set the first time semi sync is
used. This means that RUN_HOOK will have no overhead, unless semi sync
master or slave has been enabled once.

Some of the changes was just to get rid of warnings for embedded server

Part of MDEV-13073 AliSQL Optimize performance of semisync

The idea it to use a dedicated lock detecting if there is new data in
the master's binary log instead of the overused LOCK_log.

Changes:
- Use dedicated COND variables for the relay and binary log signaling.
  This was needed as we where the old 'update_cond' variable was used
  with different mutex's, which could cause deadlocks.
   - Relay log uses now COND_relay_log_updated and LOCK_log
   - Binary log uses now COND_bin_log_updated and LOCK_binlog_end_pos
- Renamed signal_cnt to relay_signal_cnt (as we now have two signals)
- Added some missing error handling in MYSQL_BIN_LOG::new_file_impl()
- Reformatted some comments with old style
- Renamed m_key_LOCK_binlog_end_pos to key_LOCK_binlog_end_pos
- Changed 'signal_update()' to update_binlog_end_pos() which works for
  both relay and binary log

Part of MDEV-13073 AliSQL Optimize performance of semisync

Did the following renames to match other similar variables
key_ss_mutex_LOCK_binlog_       > key_LOCK_bing
key_ss_cond_COND_binlog_send_  -> key_COND_binlog_send
COND_binlog_send_              -> COND_binlog_send
LOCK_binlog_                   -> LOCK_binlog

debian/mariadb-server-10.2.install does not install semisync libs.

It's better to prohibit pushdown of conditions that involve
regexp_substr() and regexp_replace() into materialized derived
tables / views until proper implementations of the get_copy()
virtual method are provided for those functions.

The support of embedded CTEs was not correct in the cases when
embedded CTEs were used multiple times. The problems occurred with
both non-recursive (bug mdev-13780) and recursive (bug mdev-14184)
embedded CTEs.

in joined table + GROUP BY + GROUP_CONCAT + HAVING + ORDER BY
[by field from HAVING] + 1 row expected

The fix is actually a port of the fix for bug #17055185 from
mysql code line (see commit f289aeeef0743508ff87211084453b3b88a6d017
by Mithun C Y into mysql-5.6). The test case for the bug #17055185
was also ported.

- FB/MySQL 5.6' MyRocks has START TRANSACTION WITH CONSISTENT
  ROCKSDB SNAPSHOT, which returns binlog position.

- MariaDB has a cross-engine START TRANSACTION WITH CONSISTENT
  SNAPSHOT. It can be used for the same purpose. Binlog position
  can be obtained from Binlog_snapshot_file/position status vars.

os_file_set_size(): If posix_fallocate() returns EINVAL, fall back
to writing zero bytes to the file. Also, remove some error log output,
and make it possible for a server shutdown to interrupt the fall-back
code.

MariaDB 10.2 used to handle the EINVAL return value from posix_fallocate()
before commit b731a5bc
which refactored os_file_set_size() to try posix_fallocate().

Why is the EINVAL returned? The GNU posix_fallocate() function
would first try the fallocate() system call, which would return
-EOPNOTSUPP for many file systems (notably, not ext4). Then, it
would fall back to extending the file one block at a time by invoking
pwrite(fd, "", 1, offset) where offset is 1 less than a multiple of
the file block size. This would fail with EINVAL if the file is in
O_DIRECT mode, because O_DIRECT requires aligned operation.

The failing test was main.gis-json

- Expand paths also for jemalloc
- Test also if tcmalloc or jemalloc is in /usr/lib64
- Take into account that .so has a version
- Remove automatic adding of flavors ( _minial, _debug). Better to
  have user specify these directly
- Changed documentation link to MariaDB
- Don't give extra error if mysqld_safe_helper doesn't exist

Also don't abort if global_status_var.global_memory_used != 0 on not
normal exit as then it's likely that not all memory is released.

MDEV-13568: Purge is not blocked by LOCK TABLES. Should it?

MDEV-13893/MDEV-12699: Crash recovery of corrupted or non-decryptable
pages is broken.

Signed-off-by: Daniel Black <daniel@linux.vnet.ibm.com>

When MariaDB 10.1.0 introduced table options for encryption and
compression, it unnecessarily changed
ha_innobase::check_if_supported_inplace_alter() so that ALGORITHM=COPY
is forced when these parameters differ.

A better solution is to move the check to innobase_need_rebuild().
In that way, the ALGORITHM=INPLACE interface (yes, the syntax is
very misleading) can be used for rebuilding the table much more
efficiently, with merge sort, with no undo logging, and allowing
concurrent DML operations.

If InnoDB or XtraDB recovered committed transactions at server
startup, but the processing of recovered transactions was
prevented by innodb_read_only or by innodb_force_recovery,
an assertion would fail at shutdown.

This bug was originally reproduced when Mariabackup executed
InnoDB shutdown after preparing (applying redo log into) a backup.

trx_free_prepared(): Allow TRX_STATE_COMMITTED_IN_MEMORY.

trx_undo_free_prepared(): Allow any undo log state. For transactions
that were resurrected in TRX_STATE_COMMITTED_IN_MEMORY
the undo log state would have been reset by trx_undo_set_state_at_finish().

Forgot to put the updated rocksdb.result in

Downscale rocksdb.add_index_inplace_sstfilewriter to be 10x smaller

Fix a race condition in the testcase.