Menu mnemonics not active after pressing the Alt key

The underline state can get out of whack as follows:
- Start the app: java -cp Hello.jar hello.HelloMenu
- Press Alt, release key, Press D (the underlines appear, D mnemonic is operative)
- Press Esc
- BUG: Press Alt (no underlines; D mnemonic inoperative)
- BUG: Press Esc, Press Alt, Press Esc (back in client area), Press D, Menu pops up even though not in menu system

Be aware of these bugs when investigating:
- JDK-8158669: If using Alt + D together wait a second. There is a bug where if you press Alt and a mnemonic together and quickly release the keys the menu will popup and disappear. Alt, release, D works OK.
- JDK-8158671: When using JAWS most of the time you won't hear "Debug" when the menu bar gets focus; apparently a focus event is not being fired. The only time you will hear it if focus was on Edit then Esc is pressed, then Alt is pressed; apparently the movement of focus from Edit to Debug is what causes a focus event to be fired.

The workaround is to press downarrow instead of the mnemonic.