<i18n dev> Integrated: 8225641: Calendar.roll(int field) does not work correctly for WEEK_OF_YEAR

[Justin Lu]

On Tue, 14 Mar 2023 22:16:45 GMT, Justin Lu <jlu at openjdk.org> wrote:

> This PR fixes the bug which occurred when `Calendar.roll(WEEK_OF_YEAR)` rolled into a minimal first week with an invalid `WEEK_OF_YEAR` and `DAY_OF_WEEK` combo.
> 
> For example, Rolling _Monday, 30 December 2019_ by 1 week produced _Monday, 31 December 2018_, which is incorrect. This is because `WEEK_OF_YEAR` is rolled from 52 to 1, and the original `DAY_OF_WEEK` is 1. However, there is no Monday in week 1 of 2019. This is exposed when a future method calls `Calendar.complete()`, which eventually calculates a `fixedDate` with the invalid `WEEK_OF_YEAR` and `DAY_OF_WEEK` combo.
> 
> To prevent this, a check is added for rolls into week 1, which determines if the first week is minimal. If it is indeed minimal, then it is checked if  `DAY_OF_WEEK` exists in that week, if not, `WEEK_OF_YEAR` must be incremented by one.
> 
> After the fix, Rolling _Monday, 30 December 2019_ by 1 week produces _Monday, 7 January 2019_

This pull request has now been integrated.

Changeset: a324fa26
Author:    Justin Lu <jlu at openjdk.org>
Committer: Naoto Sato <naoto at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/a324fa2639d29f0c5b2928e7f15ec67e396c2648
Stats:     188 lines in 2 files changed: 186 ins; 0 del; 2 mod

8225641: Calendar.roll(int field) does not work correctly for WEEK_OF_YEAR

Reviewed-by: naoto

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PR: https://git.openjdk.org/jdk/pull/13031