DateFormatSymbols.getInstance(Locale.ROOT) behaves more closely to English locale for targetSdkVersion <= 29
In Android Q or before, when LocaleData class tries to load {@link Locale#ROOT} data, en_US_POSIX
locale data is incorrectly loaded.
The class used to pass "und" string as BCP47 language tag to our jni code, which then
passes the string as as ICU Locale ID to ICU4C. ICU4C 63 or older version doesn't recognize
"und" as a valid locale id, and fallback the default locale. The default locale is
normally selected in the Locale picker in the Settings app by the user and set via
frameworks. But this class statically cached the ROOT locale data before the
default locale being set by framework. Thus, in Q or before, en_US_POSIX data is loaded.
As https://unicode-org.atlassian.net/browse/ICU-20273, an upstream bug, is fixed,
ICU version 64.1 resolved inconsistent behavior of
"root", "und" and "" (empty) Locale ID which libcore previously relied on, and they are
recognized correctly as {@link Locale#ROOT} since R. This ChangeId gated the change,
and fallback to the old behavior by checking targetSdkVersion version.
Bug: 159514442
Bug: 159047832
Test: atest CtsLibcoreTestCases
Change-Id: I62207fcb104bbc5d1d970b57b13d8f8ecb1e1ba0
4 files changed