RFR: 8089398: [ChoiceBox, ComboBox] throws NPE on setting value on null selectionModel [v6]

[Ajit Ghaisas]

On Tue, 27 Jul 2021 12:41:00 GMT, Marius Hanl <mhanl at openjdk.org> wrote:

>> This PR fixes multiple NPEs in Choice-and ComboBox, when the selection model is null.
>> 
>> ChoiceBox: 
>> - Null check in **valueProperty()** listener
>> 
>> ComboBox:
>> - Null check in **editableProperty()** listener
>> - Null check in **valueProperty()** listener
>> - Null check in **ComboBoxListViewSkin#updateValue()**
>> - Null check in **ComboBoxListViewSkin#layoutChildren()**
>> - 2x Null check in **ComboBoxListViewSkin#createListView()**
>> 
>> ~~The tests checks, that no NPE is printed to the console.
>> Some checks, that the set value is still displayed (either in the ComboBox button cell or the ChoiceBox display label)~~
>
> Marius Hanl has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fixed another NPE on skin creation when the cbx selection model is null

The latest patch does not apply cleanly due to the change in copyright headers.
It was fixed in - [JDK-8270960](https://bugs.openjdk.java.net/browse/JDK-8270960)

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PR: https://git.openjdk.java.net/jfx/pull/557