After MDEV-12288 and MDEV-13536, the DB_TRX_ID of old clustered index
records for which no history is available should be reset to 0.

This caused crashes in online table-rebuilding ALTER, because the
row_log_table_apply() is built on the assumption that the PRIMARY KEY
together with DB_TRX_ID,DB_ROLL_PTR identifies the record.

Both when copying the old table and when writing log about changes to
the old table, we must map "old" DB_TRX_ID to 0. "old" here is simply
"older than the trx_id of the ALTER TABLE transaction", because
the MDL_EXCLUSIVE (and exclusive InnoDB table lock) in
ha_innobase::prepare_inplace_alter_table() forces any transactions
accessing the table to commit or rollback. So, we know that we can
safely reset any DB_TRX_ID in the table that is older than the
transaction ID of the ALTER TABLE, because the undo log history would be
lost in a table-rebuilding ALTER.

Note: After a table-rebuilding online ALTER TABLE, the rebuilt table
may end up containing some nonzero DB_TRX_ID columns. The apply logic
identifies the rows by the combination of PRIMARY KEY and DB_TRX_ID.
These nonzero DB_TRX_ID would necessarily refer to concurrent DML
operations that were started during ha_innobase::inplace_alter_table().

row_log_allocate(): Add a parameter for the ALTER TABLE transaction.

row_log_t::min_trx: The ALTER TABLE transaction ID.

trx_id_check(): A debug function to check that DB_TRX_ID makes sense
(is either 0 or bigger than the ALTER TABLE transaction ID).

reset_trx_id[]: The reset DB_TRX_ID,DB_ROLL_PTR columns.

row_log_table_delete(), row_log_table_get_pk(): Reset the
DB_TRX_ID,DB_ROLL_PTR when they precede the ALTER TABLE transaction.

row_log_table_apply_delete(), row_log_table_apply_update():
Assert trx_id_check().

row_merge_insert_index_tuples(): Remove the unused parameter trx_id.

row_merge_read_clustered_index(): In a table-rebuilding ALTER,
reset the DB_TRX_ID,DB_ROLL_PTR when they precede the ALTER TABLE
transaction. Assert trx_id_check() on clustered index records that
are being buffered.

Storage engine independent support for column compression.

TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT,
VARCHAR and VARBINARY columns can be compressed.

New COMPRESSED column attribute added:
COMPRESSED[=<compression_method>]

System variables added:
column_compression_threshold
column_compression_zlib_level
column_compression_zlib_strategy
column_compression_zlib_wrap

Status variables added:
Column_compressions
Column_decompressions

Limitations:
- the only supported method currently is zlib
- CSV storage engine stores data uncompressed on-disk even if COMPRESSED
  attribute is present
- it is not possible to create indexes over compressed columns.

It doesn't serve any purpose, but generates extra virtual function call.

Updated qc_info tests, added new test that checks HITS is incremented.

Added hit_count field to Query_cache_query and methods to get and increment it.
The counter is incremented when query results are read from query cache.

READ_RECORD read_record;
...
// this
// read_record.read_record(&read_record);
// becomes just
read_record.read_record();

Force -march=i686 (just like innodb used to do for years).

And disable query_response_time plugin, it fails to compile with

/mnt/server/plugin/query_response_time/query_response_time.cc:279: error: unable to find a register to spill in class ‘GENERAL_REGS’
/mnt/server/plugin/query_response_time/query_response_time.cc:279: error: this is the insn:
(insn:HI 70 69 71 9 /mnt/server/include/my_atomic.h:194 (parallel [
            (set (reg:DI 82)
                (mem/v:DI (plus:SI (reg/f:SI 79)
                        (reg:SI 78)) [-1 S8 A32]))
            (set (mem/v:DI (plus:SI (reg/f:SI 79)
                        (reg:SI 78)) [-1 S8 A32])
                (unspec_volatile:DI [
                        (mem/v:DI (plus:SI (reg/f:SI 79)
                                (reg:SI 78)) [-1 S8 A32])
                        (reg:DI 82)
                        (reg:SI 83)
                        (reg:SI 84)
                    ] 10))
            (set (reg:CCZ 17 flags)
                (compare:CCZ (unspec_volatile:DI [
                            (mem/v:DI (plus:SI (reg/f:SI 79)
                                    (reg:SI 78)) [-1 S8 A32])
                            (reg:DI 82)
                            (reg:SI 83)
                            (reg:SI 84)
                        ] 11)
                    (reg:DI 82)))
        ]) 1101 {*sync_double_compare_and_swap_ccdi_pic} (insn_list:REG_DEP_TRUE 68 (insn_list:REG_DEP_TRUE 69 (nil)))
    (expr_list:REG_DEAD (reg:SI 84)
        (expr_list:REG_DEAD (reg:SI 83)
            (nil))))

only do it before crashing.

Otherwise it introduces a noticable slowdown and,
most importantly, changes errno, when the caller
doesn't expect it.

In the test, SET GLOBAL innodb_purge_rseg_truncate_frequency = 1
in order to ensure that everything is purged in the slow shutdown.

This could be viewed as a flaw of the slow shutdown.

This address is from reserved range (rfc5737), and this ensures that DNS
won't resolve it into a name

the test expects 192.168.0.1 not to resolve to anything.
this is a fragile assumption. use 127.0.0.2 instead
(which only marginally better)

on many builders oqgraph failed to compile because isfinite wasn't defined.

fix this mess of ifdefs/defines to work properly no matter
whether isfinite/isnan/isinf is a function or a macro
and whether stl header undefines it or not.

and remove the hackish workaround from oqgraph.

Fixed thd_set_peer_addr() to propagate host error count from
ip_to_hostname() to check_connection(), which tests this count to clear
errors affter successful authentication.

Fix minor typo.

This bug was a regression caused by MDEV-12698.

On non-leaf pages, the delete-mark flag in the node pointer records is
basically garbage. (Delete-marking only makes sense at the leaf level
anyway. The purpose of the delete-mark is to tell MVCC, locking and purge
that a leaf-level record does not exist in the READ UNCOMMITTED view,
but it used to exist.)
Node pointer records and non-leaf pages are glue that attaches multiple
leaf pages to an index. This glue is supposed to be transparent to the
transactional layer.

When a page is split, InnoDB creates a node pointer record out of the
child page record that the cursor is positioned on. The node pointer record
for the parent page will be a copy of the child page record, amended with
the child page number. If the child page record happened to carry the
delete-mark flag, then the node pointer record would also carry this flag
(even though the flag makes no sense outside child pages).

(On a related note, for the first node pointer record in the first
node pointer page of each tree level, if the MIN_REC_FLAG is set,
the rest of the record contents (except the child page number)
is basically garbage. From this garbage you could deduce at which point
the child was originally split.)

page_scan_method_t: Replace with bool, as there are only 2 values.

dict_stats_scan_page(): Replace the parameter scan_method with is_leaf.
Ignore the bogus (garbage) delete-mark flag if !is_leaf.

The problem was that select_gtid_pos_table() was called by IO thread
without mutex protection.

This is to get core's in mysql-test-run if server doesn't die in shutdown

- Added inline lex_string_cmp() to replace my_strcase_cmp().
- Added inline lex_string_eq to first compares lengths before comparing strings

WSREP_LOG increased the stack size of all function, where it was used,
with 1024 bytes, even if it would never called. What's worse is that one
a Mac with Lion 10.7, the stack size was increased with 1024* number of
calls per function.

By moving WSREP_LOG() to a function, the stack size on Lion in function
mysql_execute() was reduced from 18K to 12K. On my main Linux machine
with gcc 5.4 the reduction was from 5k to 4k.

Before this patch running full mtr generated some 70 cores (at least
on systemd). Now no cores should be generated.

- Changed DBUG_ABORT()'s used by mysql-test-run to DBUG_SUICIDE()
- Changed DBUG_ABORT() used to crash server with core to DBUG_ASSERT(0)
- DBUG_ASSERT now flushes DBUG files

The old behavior of returning the affected rows for the last statement
in a stored procedure was more an accident than design. Having the number
of affected rows for all sub statements is more useful and will not change
just because on changes the order of statements in the stored procedure.

- Changed also a few ;; to ;

This fixes MDEV-7742 and MDEV-8305 (Allow user to specify if stored
procedures should be logged in the slow and general log)

New functionality:
- Added new variables log_slow_disable_statements and log_disable_statements
  that can be used to disable logging of certain queries to slow and
  general log. Currently supported options are 'admin', 'call', 'slave'
  and 'sp'.
  Defaults are as before. Only 'sp' (stored procedure statements) is
  disabled for  slow and general_log.
- Slow log to files now includes the following new information:
  - When logging stored procedure statements the name of stored
    procedure is logged.
  - Number of created tmp_tables, tmp_disk_tables and the space used
    by temporary tables.
- When logging 'call', the logged status now contains the sum of all
  included statements.  Before only 'time' was correct.
- Added filsort_priority_queue as an option for log_slow_filter (this
  variable existed before, but was not exposed)
- Added support for BIT types in my_getopt()

Mapped some old variables to bitmaps (old variables can still be used)
- Variable 'log_queries_not_using_indexes' is mapped to
  log_slow_filter='not_using_index'
- Variable 'log_slow_slave_statements' is mapped to
  log_slow_disabled_statements='slave'
- Variable 'log_slow_admin_statements' is mapped to
  log_slow_disabled_statements='admin'
- All the above variables are changed to session variables from global
  variables

Other things:
- Simplified LOGGER::log_command. We don't need to check for super if
  OPTION_LOG_OFF is set as this flag can only be set if one is a super
  user.
- Removed some setting of enable_slow_log as it's guaranteed to be set by
  mysql_parse()
- mysql_admin_table() now sets thd->enable_slow_log
- Added prepare_logs_for_admin_command() to reset thd->enable_slow_log if
  needed.
- Added new functions to store, restore and add slow query status
- Added new functions to store and restore query start time
- Reorganized Sub_statement_state according to types
- Added code in dispatch_command() to ensure that
  thd->reset_for_next_command() is always called for a query.
- Added thd->last_sql_command to simplify checking of what was the type
  of the last command. Needed when logging to slow log as lex->sql_command
  may have changed before slow logging is called.
- Moved QPLAN_TMP_... to where status for tmp tables are updated
- Added new THD variable, affected_rows, to be able to correctly log
  number of affected rows to slow log.

If compiling a non DBUG binary with
-DDBUG_ASSERT_AS_PRINTF asserts will be
changed to printf + stack trace (of stack
trace are enabled).

- Changed #ifndef DBUG_OFF to
  #ifdef DBUG_ASSERT_EXISTS
  for those DBUG_OFF that was just used to enable
  assert
- Assert checking that could greatly impact
  performance where changed to DBUG_ASSERT_SLOW which
  is not affected by DBUG_ASSERT_AS_PRINTF
- Added one extra option to my_print_stacktrace() to
  get more silent in case of stack trace printing as
  part of assert.