icu::TimeZone::createDefault() was returning the timezone that was set
when current_time_zone() was first called or the timezone set via
set_current_time_zone().
This meant that even when the system timezone changed and we instructed
all WebContent processes to invoke
ConnectionFromClient::system_time_zone_changed(), the updated timezone
system was not being used as we fetched from icu's default timezone.
icu::TimeZone::detectHostTimeZone() gets the timezone from the current
host system configuration and ensures we are always synced with the host
if we have no timezone cache.
Some callers need the raw nul-terminated c-string in this callback, to
pass to some other ICU method. But other callers will want a StringView.
We know the length already in `icu_string_enumeration_to_list`, so let's
just pass it along to avoid `strlen`.
We were manually doing this for the calendar keyword, and would need to
do so for the collation keyword as well. I wasn't aware of this API
originally, so let's start using it.
On Windows, ICU does not look at the TZ environment variable at all. So
to support changing time zones in test-js, let's set ICU's default time
zone directly.
Note that we no longer deal with "null" time zone strings. We just cache
whatever ICU thinks is the current time zone before attempting to change
it, for which we never have a null result.
Co-authored-by: Andrew Kaster <andrew@ladybird.org>
This updates our local ICU overlay port to use ICU 76.1. This includes
Unicode 16 and CLDR 46.
Upstream vcpkg is not able to supply versions past 74 yet due to various
dependency issues, but we are able to use this version ourselves. The
overlay port now includes a patch to revert ICU's dependence on autoconf
2.72 for now, as this version is not yet available on all systems.
All of the test changes were cross-referenced with Firefox to ensure
correctness.
