[Bug 43691] focus tracking broken with desktop switches

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=43691

--- Comment #11 from Rafał Mużyło  ---
> do you have a quick testcase to test this behavior?

Well, nothing off the top of my head, but I've run into multiple simple games
and game-like apps that pause audio upon loosing focus, but don't minimize.

In those, the simplest way to show the problem is to run the app, switch to a
different window on the same desktop to get the app to pause, then switch to a
different desktop and switch back.

Without this patch, the apps treat minimize/unminimize cycle that wine does as
if they were regaining focus and unpause (start playing music). But this
shouldn't be the case if they aren't *actually* regaining the focus.