On Thu, 9 Apr 2026 18:01:34 GMT, Sergey Bylokhov <[email protected]> wrote:
>> The bug happens when List.select(int) is used in multiple selection mode. It >> only appears when the List is added to a Frame, because in that case, the >> selection is handled by the platform peer, and the internal logic in the >> List class is skipped. >> >> To fix this, the code now uses >> [addSelectionInterval](https://github.com/openjdk/jdk/blob/910bb68e5191f830ff6f3dff5753e4e5f6214a7b/src/java.desktop/share/classes/javax/swing/ListSelectionModel.java#L93) >> instead of setSelectedIndex. This method works correctly for multiple >> selection mode when using JList as the delegate on macOS. >> >> I added DeselectionUnitTest and SelectionUnitTest tests for some selection >> and deselection cases. At first, it was one big test, but I split it because >> it got too large. >> >> **Notes on invalid index handling** >> According to the java.awt.List >> [spec](https://github.com/openjdk/jdk/blob/0e5655e6680762a99b5aecb58369b880ea913565/src/java.desktop/share/classes/java/awt/List.java#L573), >> using invalid indexes is undefined behavior. For now, I have decided not to >> validate these cases fully in this patch, but I did add a check in the >> `LWListPeer.select()` to handle them more safely. >> >> The previously used setSelectedIndex method >> [ignored](https://github.com/openjdk/jdk/blob/0e5655e6680762a99b5aecb58369b880ea913565/src/java.desktop/share/classes/javax/swing/JList.java#L2229) >> indexes greater than the list size, unlike addSelectionInterval. So I added >> an explicit check to skip all indexes larger than the list size. >> >> Later, I discovered that passing a negative index not only causes an >> exception (which is acceptable, since it's undefined behavior), but also >> leaves the peer in an inconsistent state. This happens because >> setSkipStateChangedEvent(false) at the end of LWListPeer.select() is not >> called if an exception is thrown. >> >> To prevent this, I added a check to skip all negative values as well. As a >> result, the peer now cleanly ignores all out-of-range indexes. >> >> **Description of how invalid indexes are handled on other platforms:** >> - The shared code in java.awt.List stores elements and selection >> separately, so it accepts invalid indexes. This can cause exceptions if the >> selection and data become out of sync. >> - On Windows, all invalid indexes are ignored, except for the special value >> -1, which is used to select or deselect all elements. This happens because >> the indexes are passed to the win api without validation. >> - XAWT uses the same logic as the shared code, so it can... > > Sergey Bylokhov has updated the pull request with a new target base due to a > merge or a rebase. The pull request now contains 11 commits: > > - add @build > - reuse /test/lib > - Implement LWListPeer.setMultipleMode > - Update LWListPeer.java > - Merge branch 'master' into JDK-8369327 > - Merge branch 'openjdk:master' into JDK-8369327 > - Update ProblemList.txt > - Update SelectInvalid.java > - Validate "index >= 0 && index < model.getSize()" > - Create SelectInvalid.java > - ... and 1 more: https://git.openjdk.org/jdk/compare/f21e47db...15732626 LGTM ------------- Marked as reviewed by azvegint (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/27682#pullrequestreview-4115966216
