unix_timestamp() and time_to_sec() are hybrid items,
  returning integer or double depending on the argument.

  TIMESTAMP -> TIMESTAMP(6)
  TIME -> TIME(6)
in general_log and slow_log tables.

include/my_sys.h:
  use constants

sql/event_parse_data.cc:
  don't use "not_used" variable
sql/item_timefunc.cc:
  Item_temporal_func::fix_length_and_dec()
  and other changes
sql/item_timefunc.h:
  introducing Item_timefunc::fix_length_and_dec()
sql/share/errmsg.txt:
  don't say "column X" in the error message that used not only for columns

* my_getsystime() is only an interval timer. Its value can beused for calculating
  time intervals.
* renamed my_getsystime() to my_interval_timer(), to make the semantics
  clearer and let the compiler catch wrong usages of my_getsystime()
  (also future ones, that may come in merges).
* increased its granularity from 100ns to 1ns, old value was for UUID,
  but as UUID can no longer use it directly there is no need to downgrade
  the OS provided value
* fixed the UUID code to anchor the my_interval_timer() on the epoch, as
  required by the UUID standard. That is, this was only needed by UUID,
  and now I've moved it to UUID code from my_getsystime().
* fixed other wrong usages of my_getsystime() - e.g. in calculating
  times for pthread_cond_timedwait. It was buggy and could've caused
  long waits if OS clock would be changed.

include/my_time.h:
  remove duplicate defines.
  cast to ulonglong to avoid overflow
sql/field.cc:
  perform sign extension when reading packed TIME values
sql/item_cmpfunc.cc:
  when converting a string to a date for the purpose of comparing it with another date,
  we should ignore strict sql mode.
sql/item_timefunc.cc:
  better error message
sql/item_timefunc.h:
  limit decimals appropriately
sql/share/errmsg.txt:
  don't refer to an object as a "column" in error messages that are used not only for columns.

Prior to this patch it returned microseconds since 1 Jan 1601 (Windows epoch)

implement Item_cache_int::getdate() and Item_cache_int::save_in_field()
that handle the case of the cached packed datetime value.

rewrite get_innobase_type_from_mysql_type() to use types as reported
by the Field objects, instead of relying on ad-hoc assumptions.

certain values of X.

- Fixes for type-conversion
  (time_t   is not interchangeable  with  my_time_t on Windows as time_t s 64 bit while my_time_t is long)
- BIGENDIAN-> ARCH_BIGENDIAN . 
  BIGENDIAN constant  is defined in winsock2.h (as 0)
- added explicit cast for longlong->double conversion in sql/item.h  (fixed many warnings) 

Also, HAVE_SNPRINTF is now defined and snprintf is defined to _snprintf in config-win.h

fix a typo in the boundary test.
simplify make_truncated_value_warning call.

fix a typo in the boundary test.
simplify make_truncated_value_warning call.

lp:737496 Assertion `(was_cut & 1) == 0' failed in Field_temporal::store_TIME_with_warning() in 5.1-micro

fix incorrect assert

fix the return value of Item_func_coalesce::get_date()

implement Item_func_min_max::get_date()

better default for Field::cast_to_int_type()

respect fuzzydate flags in Item_*::get_date() methods

and a different fix for lp:736370

cache temporal expression in Item_cache_int, not in Item_string.
invoke get_datetime_value() to create a correct Item_cache_int.
Implement Item_cache_int::clone, as it's a proper constant

Implement Item_func_coalesce::get_date()

lp:736370 Datetime functions in subquery context cause wrong result and bogus warnings in mysql-5.1-micro

Don't cache temporal value in an Item_string, it is compared differently.

and a test case for lp:736370 Datetime functions in subquery context cause wrong result

  Use dedicated  do_field_temporal() for Copy_field.
* check_time_range() needs to know TIME's precision to use the
  correct max value.

partial fix

Two problems:
* Item_func_convert_tz() did not tell args[0] that it needs
  TIME_NO_ZERO_IN_DATE result
* Item_func_timediff did not respect fuzzy_date limitations,
  truncated seconds when casting to signed long, resulting in
  invalid time value (hours, seconds = (uint)-1).

add missing size_of() methods to new Field* classes

issue a warning when a datetime is truncated for storing in a TIME column.
this automatically prevents optimizer from using indexes when comparing time column to a datetime

many changes:
* NOT_FIXED_DEC now create hires fields, not old ones.
  As a result, temp tables preserve microseconds (on DISTINCT, GROUP BY)
* I_S tables force decimals=0 on temporal types (backward compatibility)
* Item_func_coalesce calculates decimals for temporal types
* no precision for TIME/DATETIME in CAST means 0, not NOT_FIXED_DEC
* addtime/timediff calculate decimals from arguments (not NOT_FIXED_DEC)

sql/field.h:
  NOT_FIXED_DEC now create hires fields, not old ones
sql/item.h:
  force decimals=0 for I_S tables
sql/item_cmpfunc.cc:
  Item_func_coalesce calculates decimals for temporal types
sql/item_create.cc:
  no precision for TIME/DATETIME in CAST means 0, not NOT_FIXED_DEC
sql/item_timefunc.cc:
  addtime calculates decimals from arguments (not NOT_FIXED_DEC)
sql/item_timefunc.h:
  timediff calculates decimals from arguments (not NOT_FIXED_DEC)