I feel that is a bit overkill for a single application, which is using the lock in an invalid way anyway.
Maybe, but I don't like the way this patch basically feels like it's hacking around the current behaviour.
I'd also assert that "invalid" is often not a very meaningful word when it comes to Wine. There's documented API, sure, but programs making assumptions about internals is commonplace, and something that's pretty much always been within Wine's scope to fix.