if two threads were calling mi_assign_to_key_cache() for the same table,
one could change share->key_cache while the other was having
share->key_cache->op_lock locked. The other thread would crash then,
trying to unlock share->key_cache->op_lock (because it would be a different mutex).

fixed by caching the value of share->key_cache in a local variable. The thread can still
call flush_key_blocks() for an unassigned keycache, but it's harmless.

in some VMs readline thinks that the window size is zero. ignore it.

MDEV-5461 Assertion `length <= column->length' fails in write_block_record with functions in select list, GROUP BY, ORDER BY

Old code in create_tmp_table(), that created an extra one-byte field (recinfo)
before every NULL-able grouping field (Field) in the tmp table, did not actually work.
Because the matching code in end_update(), that was supposed to update this byte,
was using a wrong offset, updating the first byte of the Field, not a byte before it.
Normally this wasn't an issue, because the Field value (written later in end_update)
was overwriting this byte anyway. But in this bug the Field was Field_null, with zero
length, so end_update() was overwriting the first byte of the following field.
And the following field was not-nullable constant, which was stored only once in
create_tmp_table and never updated later.

Fixed by removing the code that didn't do any useful work anyway.

Added variable "OLD_MODE" that can be used to turn off the new behavior

mysql-test/r/insert.result:
  Added test case
mysql-test/r/mysqld--help.result:
  Added old_mode
mysql-test/suite/sys_vars/r/old_mode_basic.result:
  Added testing of new variable
mysql-test/suite/sys_vars/t/old_mode_basic.test:
  Added testing of new variable
mysql-test/t/insert.test:
  Added test case
sql/sql_class.h:
  Added bit flags for OLD_MODE
sql/sql_insert.cc:
  Disable duplicate key warnings for INSERT IGNORE of OLD_MODE NO_DUP_KEY_WARNINGS_WITH_IGNORE is used
sql/sql_show.cc:
  Don't show progress reporting on SHOW PROCESSLIST if OLD_MODE NO_PROGRESS_INFO is used
sql/sys_vars.cc:
  Added OLD_MODE

sql/item.h:
  Added cache for setup_natural_join_row_types
sql/sql_base.cc:
  Cache old value of first_name_resolution_table for next call.
  (It's not safe to try to recalculate the value as the join structure may have been changed by the optimizer)

Added test cases

mysql-test/r/mysql_tzinfo_to_sql_symlink.result:
  Updated results
mysql-test/std_data/zoneinfo/garbage:
  test file
mysql-test/std_data/zoneinfo/ignored.tab:
  test file
mysql-test/t/mysql_tzinfo_to_sql_symlink.test:
  Added test cases for all options
sql/tztime.cc:
  Better error messages.
  Fixed wrong place for 'continue'

Marked very long running tests as big_test

Problem was that ALTER TABLE DISABLE KEYS incremented create_trid for the table,
which made the new index entries invisible until the global trid catched up.

Fixed by only updating create_trid if we are rewriting all rows and indexes.


mysql-test/suite/maria/alter.result:
  Added test case
mysql-test/suite/maria/alter.test:
  Added test case
storage/maria/ha_maria.cc:
  Only updating create_trid if we are doing a full repair (and thus rewriting all rows and indexes).
storage/maria/trnman.c:
  More DBUG_PRINT

Assertion `mon > 0 && mon < 13' failed.'

MDEV-5337: Wrong result in mariadb 5.5.32 with ORDER BY + LIMIT when 
index_condition_pushdown=on
- in test_if_skip_sort_order(), correct the condition under which
  we have the code that restores the previously pushed index condition.

- in test_if_skip_sort_order(), correct the condition under which
  we have the code that restores the previously pushed index condition.

- Warnings about wrong symlink messages or non-timezone files with '.tab' are now only given if run with --verbose
- Added long option handling
- Added --help, --verbose and --version options


sql/tztime.cc:
  Add usage of my_getopt, to get long options

The crash happened because Item_func_monthname was derived from
Item_func_month, so Item_func_monthname::is_null() did not work fine.
Backporting a change from 5.5: Item_func_monthname is now derived from
Item_str_func.

Main fix was to not cache derivied tables as they may be temporary tables that are deleted before the next query.
This was a bit tricky as Item_field::fix_fields depended on cached_tables to be set to resolve some columns.



mysql-test/r/sp-bugs.result:
  Added test case
mysql-test/t/sp-bugs.test:
  Added test case
sql/item.cc:
  Fixed fix_outer_field to handle case where found field did not have in cached_table
  Idea is that if cached_table is not avaliable, use from_field->table->pos_in_table_list instead
sql/records.cc:
  Also accept INTERNAL_TMP_TABLE for memmap
sql/sql_base.cc:
  More DBUG_PRINT
  Fixed that setup_natural_join_row_types() is not run twice.
  Original code modified context->first_name_resolution_table also for second executions.
  This was wrong as this could give wrong results if some joins had been optimized away between calls.
sql/sql_derived.cc:
  Mark derived tables as internal temporary tables (INTERNAL_TMP_TABLE), not as NON_TRANSACTIONAL_TMP_TABLE.
  This is more correct as the tables are not visible by the end user.
sql/sql_insert.cc:
  Reset pos_in_table_list before calling fix_fields.
  One of the consequences of the change of not caching all generated tables in Item_ident is that
  pos_in_table_list needs to be correct in calls to fix_fields.
sql/sql_lex.cc:
  More DBUG_PRINT
sql/sql_parse.cc:
  Don't cache derivied tables as they may be temporary tables that are deleted before the next query
sql/sql_select.cc:
  Reset table_vector. This was required as some code checked the vector to see if temporary tables had already been created.
sql/table.cc:
  Mark tables with field translations as cacheable (as these will not disapper between stmt executions.

storage/tokudb/mysql-test/tokudb_bugs/r/5733_innodb.result:
  Speed up test
storage/tokudb/mysql-test/tokudb_bugs/r/5733_tokudb.result:
  Speed up test
  Fix results
storage/tokudb/mysql-test/tokudb_bugs/r/xa-6.result:
  Ensure that mysql.proc is properly closed
storage/tokudb/mysql-test/tokudb_bugs/t/5733_innodb.test:
  Speed up test
storage/tokudb/mysql-test/tokudb_bugs/t/5733_tokudb.test:
  Speed up test
  Accept both index and range scan for one query
storage/tokudb/mysql-test/tokudb_bugs/t/xa-6.test:
  Ensure that mysql.proc is properly closed

        small fix in the --replace_regex template.

        Plugins get error notifications only when my_message_sql() is called.
        But errors are launched with THD::raise_condition() calls in other
        places. These are push_warning(), implementations of SIGNAL and
        RESIGNAL commands.
        So it makes sence to notify plugins there in THD::raise_condition().

- convert_subq_to_sj() must connect child select's tables into 
  parent select's TABLE_LIST::next_local chain.  
- The problem was that it took child's leaf_tables.head() which
  is different. This could cause certain tables (in this bug's case,
  child select's non-merged semi-join) not to be present in 
  TABLE_LIST::next_local chain.  Which would cause non-merged semi-join
  not to be initialized in setup_tables(), which would lead to 
  NULL pointer dereference.

- convert_subq_to_sj() must connect child select's tables into 
  parent select's TABLE_LIST::next_local chain.  
- The problem was that it took child's leaf_tables.head() which
  is different. This could cause certain tables (in this bug's case,
  child select's non-merged semi-join) not to be present in 
  TABLE_LIST::next_local chain.  Which would cause non-merged semi-join
  not to be initialized in setup_tables(), which would lead to 
  NULL pointer dereference.

THD::thd->activate_stmt_arena_if_needed() should be used to temporary activating statement arena instead of direct usage of THD::set_n_backup_active_arena() because possible such scenario:
  1) func1 saves current arena and activates copy1 of statement arena
  2) func2 saves copy1 of statement arena setup by func1 and activates copy2
  3) some changes made for copy 2
  4) func2 stores changed copy2 back to statenet arena and activates copy1
  5) func1 store unchanged copy1 back to statemnt arena (rewrite changed copy 2 so changes become lost) and activates arena which was before.

After table->file->add_index() in mysql_alter_table() the table in the engine
has the intermediate temporary structure, it's neither the original nor the
final table structure (it'll be final after successful table->file->drop_index()
call). So, when add_index() fails with a unique key violation, we cannot simply
get the failed key number and easily map it to the key name and key structure via
table->key_info[key_no].

For now we'll create this "intermediate temporary structure", emulating InnoDB
internal rules.

This bug and the fix will go away in 10.0 that uses completely different online
alter table code.

mysql-test/t/alter_table_trans.test:
  mdev:5406

THD::thd->activate_stmt_arena_if_needed() should be used to temporary activating statement arena instead of direct usage of THD::set_n_backup_active_arena() because possible such scenario:
  1) func1 saves current arena and activates copy1 of statement arena
  2) func2 saves copy1 of statement arena setup by func1 and activates copy2
  3) some changes made for copy 2
  4) func2 stores changed copy2 back to statenet arena and activates copy1
  5) func1 store unchanged copy1 back to statemnt arena (rewrite changed copy 2 so changes become lost) and activates arena which was before.

make print_no_partition_found() to respect MYF(errflag)

mysql-test/suite/parts/t/insert_ignore-5421.test:
  mdev:5421

and support MySQL CMakeLists.txt files