After fix of MDEV-6728, the KILL signal is reset at the start of query
execution. This means that in this test case, we need to wait for the
to-be-killed query to have started; otherwise the kill signal can be lost,
causing the test case to fail.

The test case deliberately crashes the server. If this crash happens in the
middle of a page write, InnoDB crash recovery recovers the page from the
doublewrite buffer, writing a message to the error log that is flagged as a
test failure by mysql-test-run. So add a suppression for this.

  on the multiple table result to obtain the same result on Windows
  and Linux (because files can be retrieved in a different order)
modified:
  storage/connect/mysql-test/connect/r/json.result
  storage/connect/mysql-test/connect/t/json.test

added:
  storage/connect/json.cpp
  storage/connect/json.h
  storage/connect/mysql-test/connect/r/json.result
  storage/connect/mysql-test/connect/std_data/biblio.jsn
  storage/connect/mysql-test/connect/std_data/expense.jsn
  storage/connect/mysql-test/connect/std_data/mulexp3.jsn
  storage/connect/mysql-test/connect/std_data/mulexp4.jsn
  storage/connect/mysql-test/connect/std_data/mulexp5.jsn
  storage/connect/mysql-test/connect/t/json.test
  storage/connect/tabjson.cpp
  storage/connect/tabjson.h
modified:
  storage/connect/CMakeLists.txt
  storage/connect/engmsg.h
  storage/connect/filamtxt.h
  storage/connect/ha_connect.cc
  storage/connect/msgid.h
  storage/connect/mycat.cc
  storage/connect/plgdbsem.h
  storage/connect/tabdos.cpp
  storage/connect/value.cpp
  storage/connect/value.h

added:
  storage/connect/json.cpp
  storage/connect/json.h
  storage/connect/mysql-test/connect/r/json.result
  storage/connect/mysql-test/connect/std_data/biblio.jsn
  storage/connect/mysql-test/connect/std_data/expense.jsn
  storage/connect/mysql-test/connect/std_data/mulexp3.jsn
  storage/connect/mysql-test/connect/std_data/mulexp4.jsn
  storage/connect/mysql-test/connect/std_data/mulexp5.jsn
  storage/connect/mysql-test/connect/t/json.test
  storage/connect/tabjson.cpp
  storage/connect/tabjson.h
modified:
  storage/connect/CMakeLists.txt
  storage/connect/engmsg.h
  storage/connect/filamtxt.h
  storage/connect/ha_connect.cc
  storage/connect/msgid.h
  storage/connect/mycat.cc
  storage/connect/plgdbsem.h
  storage/connect/tabdos.cpp
  storage/connect/value.cpp
  storage/connect/value.h

MDEV-6220 mysqldump will not backup database with --flush-logs parameter and log_error my.cnf parameter defined

some checks were "if [ -n "$err_log" ]", others were "if [ $want_syslog -eq 0 ]",
so when both are set, error log file was only partially initialized.
To avoid this ambiguity we reset want_syslog when error log file is used.

correct the check for PLUGIN_VAR_STR

mtr internally does the following:
1. $default_vardir=....
2. $opt_vardir=$default_vardir unless $opt_vardir;
3. $opt_vardir=realpath $opt_vardir unless IS_WINDOWS
4. if ($opt_vardir eq $default_vardir) { .... use /dev/shm ... }

thus we have to realpath $default_datadir too, otherwise
the comparison logic might be broken

Using a boolean flag for 'there is a RESET MASTER in progress' doesn't
work very well for multiple concurrent RESET MASTER statements.
Changed to a counter.

MDEV-7299 Assertion `m_status == DA_ERROR || m_status == DA_OK' fails on concurrent execution of DDL, queries from I_S, and KILL QUERY

Fix MDL to report an error when a wait was killed, but preserve
the old documented behavior of GET_LOCK() where killing it is not an error.

Also remove race conditions in main.create_or_replace test

revert the code in filesort that conditionally updated 'found_rows',
rely on filesort_limit_arg instead.

MDEV-7186 get_lock() crashes on Windows, main.sp_notembedded and main.trigger_notembedded fail in buildbot

user locks are not affected by lowed_case_table_names

change the test not to use absolute values of Key_blocks_unused.

reset KILL_QUERY when a new query execution is just about to be started

copy the workaround from 5.5

This patch ports the work that facebook has performed
to make innochecksum handle compressed tables.
the basic idea is to use actual innodb-code to perform
checksum verification rather than duplicating in innochecksum.cc.
to make this work, innodb code has been annotated with
lots of #ifndef UNIV_INNOCHECKSUM so that it can be
compiled outside of storage/innobase.

A new testcase is also added that verifies that innochecksum
works on compressed/non-compressed tables.

Merged from commit fabc79d2ea976c4ff5b79bfe913e6bc03ef69d42 
from https://code.google.com/p/google-mysql/

The actual steps to produce this patch are:

    take innochecksum from 5.6.14
    apply changes in innodb from facebook patches needed to make innochecksum compile
    apply changes in innochecksum from facebook patches
    add handcrafted testcase

The referenced facebook patches used are:

    https://github.com/facebook/mysql-5.6/commit/91e25120e75272db4cdbc07d0e45877d9dea5715
    https://github.com/facebook/mysql-5.6/commit/847fe76ea5239b09fa361b023c56e6be76d32046
    https://github.com/facebook/mysql-5.6/commit/1135628a5a9b3412621b93233478f3804bcef51a
    https://github.com/facebook/mysql-5.6/commit/4dbf7c240ce2f08b7d6572d9452c9779ce90641c

mysql-test/suite/maria/insert_select.result:
  Added test case
mysql-test/suite/maria/insert_select.test:
  Added test case
mysys/thr_lock.c:
  Ensure we don't allow concurrent_insert when a read_no_write lock is in use

Stage "Filling schema table" is now properly shown in 'show processlist'


mysys/mf_keycache.c:
  Simple cleanup with more comments
sql/lock.cc:
  Return to original stage after mysql_lock_tables
  Made 'Table lock' as a true stage
sql/sql_show.cc:
  Restore original stage after get_schema_tables_result

- The code that tested if
     WHERE expr=value AND expr=const
  can be rewritten to:
     WHERE const=value AND expr=const
  was incomplete in case of STRING_RESULT.
- Moving the test into a new function, to reduce duplicate code.

FULLTEXT indexes do not permit index first lookups. By calling:
ha_index_first() with a garbage parameter, random data gets overwritten
that causes the table->field array to be corrupted. Subsequently, when
the field array is accessed, a segfault occurs.

By not allowing index statistics for FULLTEXT indexes, the problem is
resolved.

Fixing a wrong assymetric code in Arg_comparator::set_cmp_func().
It existed for a long time, but showed up in 10.0.14 after the fix
for "MDEV-6666 Malformed result for CONCAT(utf8_column, binary_string)".