RFR: 8189354: ArrayIndexOutOfBoundsException when listening to selection changes on TreeTableView [v8]

[Jeanette Winzenburg]

On Tue, 27 Apr 2021 19:18:59 GMT, mstr2 <github.com+43553916+mstr2 at openjdk.org> wrote:

>> This PR fixes the implementation of `ControlUtils.reducingChange`, which incorrectly computed adjacent removed indices, thus resulting in incorrect removal notifications.
>> 
>> Since there were no unit tests for this method, I also added a bunch of tests.
>> 
>> After applying this fix, I can no longer reproduce [JDK-8189354](https://bugs.openjdk.java.net/browse/JDK-8189354) and [JDK-8189228](https://bugs.openjdk.java.net/browse/JDK-8189228).
>
> mstr2 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use MockListObserver

modules/javafx.controls/src/main/java/javafx/scene/control/MultipleSelectionModelBase.java line 806:

> 804:             bitset.clear(index);
> 805:             _nextRemove(indicesIndex, index);
> 806:             _endChange();

faintly remember that we have an issue for this (can't find it right now ..)

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PR: https://git.openjdk.java.net/jfx/pull/480