RFR: 8376492: NullPointer in ContextMenu sub-menu when graphic and style classes are changed while the menu is open [v2]

[Dmitry Markov]

On Tue, 17 Feb 2026 08:20:45 GMT, eduardsdv <duke at openjdk.org> wrote:

>> Dmitry Markov has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Remove previous ItemStyleClassListener
>
> modules/javafx.controls/src/main/java/com/sun/javafx/scene/control/ContextMenuContent.java line 1299:
> 
>> 1297:                 };
>> 1298:                 item.getStyleClass().addListener(itemStyleClassListener);
>> 1299:                 item.getProperties().put(ITEM_STYLE_CLASS_LISTENER, itemStyleClassListener);
> 
> I think the reason for the issue is, that the listener ``itemStyleClassListener`` is created and added each time the ``createChildren()`` method is called. This happens once in the constructor and each time the ``graphicProperty()`` is changed (see the lines 1188-1191). 
> 
> So, after some changes of ``graphicProperty()`` we have a number of listeners added to the ``item.getStyleClass()``, but only last one will be removed when ``dispose()`` is called.
> The ``dispose()`` method also nulls the ``label``. Therefore, if the ``item.getStyleClass()`` is changed afterwards, the listeners that have not been removed will attempt to update the **null**-label.
> 
> Therefore, I think, we not only have a NullPointerException but also a memory leak.
> 
> What about removing the old listener when a new one is created and added to the ``item.getStyleClass()`` method, as is done in the ``dispose()`` method?
> 
> 
> ListChangeListener<String> previousItemStyleClassListener = (ListChangeListener<String>)item.getProperties().put(ITEM_STYLE_CLASS_LISTENER, itemStyleClassListener);
> if (previousItemStyleClassListener!= null) {
>     item.getStyleClass().removeListener(previousItemStyleClassListener);
> }

You are right, there is a memory leak: I can see the number of `itemStyleClassListener` is growing anytime when `createChildred()` is called.

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PR Review Comment: https://git.openjdk.org/jfx/pull/2075#discussion_r2841731216