On Tue, 30 Jun 2026 17:22:25 GMT, Justin Lu <[email protected]> wrote:
> This PR corrects the special case handling in `Locale.Builder.setLocale`. The
> current handling always assumes a `Locale` matching the `ja/JP/JP` and
> `th/TH/TH` special cases will contain the correct compatibility extensions. A
> user can remove the extension or create a Locale in the form of the special
> case without the correct compatibility extension.
>
> For example, the current implementation does the following,
>
>> jshell> loc = new Builder().setLocale(Locale.of("ja", "JP",
>> "JP").stripExtensions()).build()
>> loc ==> ja_JP
>>
>> jshell> loc = new
>> Builder().setLocale(Locale.forLanguageTag("ja-JP-u-ca-foobar-x-lvariant-JP")).build()
>> loc ==> ja_JP_#u-ca-foobar
>
> That is, it silently discards the ill-formed JP variant.
>
> With assertions on, this instead becomes a `NullPointerException` when the
> extensions are not present, or an `AssertionError` when the extension has the
> wrong value.
>
> For the example above, one would expect an `IllFormedLocaleException` to be
> thrown, since without a correct compatibility extension, JP is merely an
> invalid variant and `setLocale(Locale)` throws on ill-formed fields.
>
> The changes in this PR ensure that these cases throw as expected.
>
> ---------
> - [x] I confirm that I make this contribution in accordance with the [OpenJDK
> Interim AI Policy](https://openjdk.org/legal/ai).
This pull request has now been integrated.
Changeset: d343e6c8
Author: Justin Lu <[email protected]>
URL:
https://git.openjdk.org/jdk/commit/d343e6c854f2851c3bd09d850898b0d79950e718
Stats: 131 lines in 7 files changed: 80 ins; 7 del; 44 mod
8387455: Restrict legacy Locale compatibility handling to exact matches
Reviewed-by: naoto
-------------
PR: https://git.openjdk.org/jdk/pull/31728
