Mismatches in MySQL engines test suite

Initially reported by Rich Prohaska at https://lists.launchpad.net/maria-developers/msg04772.html

Completed: Failed 37/323 tests, 88.54% were successful.

Failing test(s): engines/funcs.an_calendar
engines/funcs.datetime_function engines/funcs.db_alter_collate_ascii
engines/funcs.db_alter_collate_utf8 engines/funcs.db_use_error
engines/funcs.de_calendar_range
engines/funcs.in_calendar_2_unique_constraints_duplicate_update
engines/funcs.in_calendar_pk_constraint_duplicate_update
engines/funcs.in_calendar_pk_constraint_error
engines/funcs.in_calendar_pk_constraint_ignore
engines/funcs.in_calendar_unique_constraint_duplicate_update
engines/funcs.in_calendar_unique_constraint_error
engines/funcs.in_calendar_unique_constraint_ignore
engines/funcs.in_multicolumn_calendar_pk_constraint_duplicate_update
engines/funcs.in_multicolumn_calendar_pk_constraint_error
engines/funcs.in_multicolumn_calendar_pk_constraint_ignore
engines/funcs.in_multicolumn_calendar_unique_constraint_duplicate_update
engines/funcs.in_multicolumn_calendar_unique_constraint_error
engines/funcs.in_multicolumn_calendar_unique_constraint_ignore
engines/funcs.in_multicolumn_number_pk_constraint_duplicate_update
engines/funcs.in_number_boundary_error
engines/funcs.in_number_decimal_boundary_error
engines/funcs.ld_all_number_string_calendar_types
engines/funcs.se_join_left engines/funcs.se_join_left_outer
engines/funcs.se_join_natural_left
engines/funcs.se_join_natural_left_outer engines/funcs.sq_all
engines/funcs.sq_error engines/funcs.up_calendar_range
engines/iuds.delete_time engines/iuds.insert_decimal
engines/iuds.insert_number engines/iuds.insert_time
engines/iuds.type_bit_iuds engines/iuds.update_delete_number
engines/iuds.update_time

I found several types of mismatches.

1. Numerous extra warnings produced by MariaDB (comparing to MySQL) on value truncation, e.g. when a datetime value is inserted into a TIME field, etc. MySQL does it silently. Throwing a warning seems fine, so only result files need to be updated, but better to check where the difference comes from.

2. SQL states can be different: HY000 in MySQL vs 22007 in MariaDB. 22007 looks better, need double-check that it is always relevant and fix result files.

3. Error messages can be different: the text contains 'MariaDB' instead of 'MySQL'. Need to fix result files.

4. Some SELECTs return rows in a different order. Those are SELECTs without ORDER BY, and there is no sorted_result in test files. Need to add sorted_result and possibly update result files afterwards.

4. THere are several cases when SELECT returns different number of rows. It is usually something like
SELECT * FROM t1 WHERE a > ALL (SELECT b FROM t2)
and b contains NULL values (but not only NULLs). MariaDB does not return anything, MySQL does. Empty result set seems correct, and postgres also returns empty. Need to confirm and update result files.

5. A few cases where CURRENT_TIME() or NOW() returns different values (the tests set TIMESTAMP to a constant before, so it does not depend on the execution time). It turns out that in MySQL tests are run with GMT, on any machine, while in MariaDB it depends on the system time zone. Need to figure out where the difference comes from.