RFR: 8364405: Intermittent MenuDoubleShortcutTest failure on Linux and macOS

[Kevin Rushforth]

On Tue, 16 Sep 2025 11:05:07 GMT, Jayathirth D V <jdv at openjdk.org> wrote:

> MenuDoubleShortcutTest > nonMacMenuBarComesBeforeScene(on linux) & MenuDoubleShortcutTest > macSceneComesBeforeMenuBar(on macOS) fail intermittently.
> 
> In every failure we can see that no Accelerator event in fired `Key press event triggered no actions`.
> To initiate accelerator event we use `testKey()` method in this test. `testKey()` method uses asynchronous `Platform.runLater()` to press accelerator shortcut. We have 100ms delay after this asynchronous event to check whether accelerators events are fired, but this is not fool-proof.
> 
> So this test is updated to make sure the asynchronous event in `testKey()` is completed by using a `CountDownLatch`. Also i tried removing the delay that we have after `testKey()` call, but it looks like 100ms delay is still needed between keyPress and event callbacks.
> 
> Updated test is run 50 times on all platforms and there are no intermittent failures seen.

This looks like the right fix.

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Marked as reviewed by kcr (Lead).

PR Review: https://git.openjdk.org/jfx/pull/1906#pullrequestreview-3231041658