RFR: 8376169: JPopupMenu.setInvoker(null) causes NPE [v2]

[Prasanta Sadhukhan]

On Fri, 23 Jan 2026 18:26:20 GMT, Phil Race <prr at openjdk.org> wrote:

>> src/java.desktop/share/classes/javax/swing/JPopupMenu.java line 957:
>> 
>>> 955:         if (invoker != null) {
>>> 956:             Component oldInvoker = this.invoker;
>>> 957:             this.invoker = invoker;
>> 
>> This doesn't look right to me. Is `this.invoker == null` an invalid state?
>> 
>> I believe the only thing that requires to be guarded by `if (invoker != null)` is `invoker.addPropertyChangeListener`; maybe `ui.installUI(this)`, however, I can't see why the latter should be skipped in cases where `invoker` is `null`.
>
> I'm also not sure it is right.  It changes from an NPE to a no-op.
> Before the previous fix as well as with the current code, null will at least do uninstallUI()
> And because of this bug report it seems people expect null to be valid and presumably do something.

I did what I did seeing the spec "the component in which the popup menu is to be displayed" which I construed as the popup menu should be displayed against a component be in JMenu, JLabel, JToolTip etc and it should not be an orphaned popupmenu as I was not sure of its usecase [Even the parent bug that popup doesn't go when component is removed seems to suggest that popup should be tied to a parent]
 
but it seems the implementation can expect a orphaned/standalone popup and show it at set location
https://github.com/openjdk/jdk/blob/cba7d88ca427984ebb27a1634aab10a62c9eede1/src/java.desktop/share/classes/javax/swing/JPopupMenu.java#L996-L1014

so I updated the PR accordingly to maintain a status-quo

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PR Review Comment: https://git.openjdk.org/jdk/pull/29377#discussion_r2731136926