- Type casting was not consequent, thus when adding a DATE type with
a WEEK interval the result type was DATETIME and not DATE as is the
norm.
- By changing the order of the date internal enumerations the deviant
type casting is resolved (Item_date_add_interval::fix_length_and_dec()
which determines result type for this operation assumes that addition
of any interval with value <= INTERVAL_DAY to date value will result
in date). There are two independant places to change:
interval_names[] and interval_type.
- Print warning that says display width is not supported for datatype TIMESTAMP, if user tries to create a TIMESTAMP column with display width.
- Use display width for TIMESTAMP only in type_timestamp test to make sure warning is displayed correctly.
