RFR: 8175358: Memory leak when moving MenuButton into another Scene

[Ajit Ghaisas]

Hi Jeanette,

   Thanks for spotting additional memory leaks as part of code review.

    I have filed JDK-8244081 <https://bugs.openjdk.java.net/browse/JDK-8244081> & JDK-8244075 <https://bugs.openjdk.java.net/browse/JDK-8244075> to address them.

Regards,
Ajit

> On 27-Apr-2020, at 8:17 PM, Jeanette Winzenburg <fastegal at openjdk.java.net> wrote:
> 
> On Mon, 27 Apr 2020 11:57:58 GMT, Ajit Ghaisas <aghaisas at openjdk.org> wrote:
> 
>> Issue : https://bugs.openjdk.java.net/browse/JDK-8175358
>> 
>> Root cause : When a MenuItem is removed from a Scene, if any accelerator has been set on MenuItem, it does not get
>> removed from Scene's list of accelerators.
>> Fix : If Scene changes for a Menu, remove the registered accelerators from Scene.
>> 
>> Testing : Added a unit test that fails before the fix and passes with it.
> 
> fix looks good to me :)
> 
> Seeing the code, I think we have two follow-up issues (not introduced here, they just jump to visibility in the light
> of reading the code and recent fixes around memory leaks :)
> 
> - the listener to the control's sceneProperty is never removed, introducing a memory leak, a fix could be similar to that
>  of the recently [fixed JDK-8236840](https://bugs.openjdk.java.net/browse/JDK-8236840)
> 
> - we have the exact same issue with accelerators in a contextMenu of a control that's removed from the scene (the
>  accelerators are still active, as can be seen in adapting your test method). Not sure which collaborator should be
>  responsible for the cleanup, could be the helper class, the control, or ?
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jfx/pull/199