https://bugs.winehq.org/show_bug.cgi?id=54342
--- Comment #3 from Zeb Figura z.figura12@gmail.com --- (In reply to Zeb Figura from comment #2)
I wonder if Windows is doing an alertable wait inside of WSARecv()?
It does, but not if WSARecv() completes synchronously. Which it usually does, but isn't guaranteed to do. I'll send a patch.