Since `DateTimeZone` does not implement a `compare_objects` handler,
nor has any properties, two `DateTimeZone` instances always compare as
being equal, even if they designate totally different timezones. Even
worse, after calling `var_dump()` on these objects, the actual
comparison may yield a correct result.
We therefore introduce a `compare_objects` handlers, which prevents
different behavior before/after `var_dump()`, and which allows us to
clearly define the intended semantics.
We check that the given microsecond fraction is in the valid range
[0, 1000000[, and otherwise mark it as invalid. We also drop the
useless do loop; a plain block is sufficient here.
When getting the properties of a DatePeriod instance we have to retain
the proper classes, and when restoring a DatePeriod instance we have to
cater to DateTimeImmutable instances as well.
RFC: https://wiki.php.net/rfc/tostring_exceptions
And convert some object to string conversion related recoverable
fatal errors into Error exceptions.
Improve exception safety of internal code performing string
conversions.
Arbitrary DateInterval objects don't have well-defined comparison
semantics. Throw a warning and treat the objects as uncomparable.
Support for comparing DateInterval objects returned by
DateTime::diff() may be added in the future.
Function strftime is part of the C89 standard [1] and current systems
don't need to check for its presence anymore.
Additionally, checks for strftime function in tests have been removed
since the PHP strftime function is now always available.
1: https://port70.net/~nsz/c/c89/c89-draft.html
Changes:
- PHP_TM_GMTOFF removed
- HAVE_TM_GMTOFF replaced with HAVE_STRUCT_TM_TM_GMTOFF
- HAVE_TM_ZONE replaced with HAVE_STRUCT_TM_TM_ZONE
- HAVE_TZNAME removed
The PHP_TM_GMTOFF macro can be replaced with Autoconf's AC_CHECK_MEMBERS
that defines the HAVE_STRUCT_TM_TM_GMTOFF symbol instead of the
HAVE_TM_ZONE.
The HAVE_TZNAME symbol is not used in current code. The obsolete
HAVE_TM_ZONE symbol has been replaced with more proper
HAVE_STRUCT_TM_TM_ZONE. These are defined by the AC_STRUCT_TIMEZONE
macro.
