Fixes the following bug:

1. Use arrow keys to select a folder such as "Popular urls" (this works

if the folder was selected by searching as well e.g typing 'popu')

2. Use right arrow to enter folder
3. Use left arrow or esc to close the folder submenu. Folder item in main menu

remains highlighted and we receive a 'QEvent::Close' as expected

4. Type a letter too search
5. Search gets reset by two spurious QEvent::Close triggered by the folder loosing focus

Note that with this patch the search result will still loose focus, but this patch fixes the reset at least.

Ensure that there isn't a race condition with the isVisible check. I.e is QEvent::Close always sent _before_ the menu is actually closed despite the documentation stating "was" not will be (as far as I can tell it is).

QEvent::Close | Widget was closed (QCloseEvent).

Can the menu become closed/invisible before we are done dealing with the event or does it wait for us to deal with it? I tested it by by sleeping for 5 seconds before the isVisible test and the menu didn't close until after. But that doesn't prove it conclusively or for all cases.