FULL PRODUCT VERSION :
1.8.0_102 and additionally verified on _92 and _66

ADDITIONAL OS VERSION INFORMATION :
Ubuntu 16.04

A DESCRIPTION OF THE PROBLEM :
I have an app with a Menubar with two Menus.  Each Menu has a single MenuItem.  All of the Menus and MenuItems have mnemonicParsing set to the default (true) and a mnemonic applied via the underscore ('_') character.

When I press Alt, I can select the Menu.  However, continuing to hold Alt does not allow me to select a MenuItem.

I've seen this example work intermittently, but the larger program that I can't submit has mnemonics that never work.

This program works fine on Windows and mnemonics aren't used on the Mac.





STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
In my test program, one of the menus is File > Close.  The other is Edit > Paste.  To reproduce

1. Start the app
2. Holding the Alt key, press the E key.  The Edit Menu will be selected.
3. Continuing to hold the Alt key, press the P key.  The selecting will go back to the File Menu rather than the Paste MenuItem.



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expected to be able to select a MenuItem with the mneomic.
ACTUAL -
The MenuItem is not selected.  Focus seems to go back to the first Menu.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class MnemonicTestApp extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {

        MenuBar menubar = new MenuBar();

        Menu fileMenu = new Menu("_File");
        fileMenu.setMnemonicParsing(true);

        MenuItem closeItem = new MenuItem("_Close");
        closeItem.setId( "closeItem");
        closeItem.setMnemonicParsing(true);
        closeItem.setOnAction( this::activate );

        fileMenu.getItems().add( closeItem );

        Menu editMenu = new Menu("_Edit");
        editMenu.setMnemonicParsing(true);

        MenuItem pasteItem = new MenuItem("_Paste");
        pasteItem.setId( "pasteItem" );
        pasteItem.setMnemonicParsing( true );
        pasteItem.setOnAction( this::activate );

        editMenu.getItems().add( pasteItem );

        menubar.getMenus().addAll( fileMenu, editMenu  );

        VBox vbox = new VBox();
        vbox.getChildren().addAll( menubar );

        Scene scene = new Scene( vbox, 480, 320 );

        primaryStage.setScene( scene );
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

    private void activate(Event event) {
        System.out.println("source=" + event.getSource());
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Don't use mnemonics.