Thank you. This third bug is an interesting one... Please confirm whether you still get the freeze with the previous build and if this new one solves it.
https://ci.appveyor.com/project/cfil...vdy8/artifacts
I tried various things on all my Windows 7/8/10 virtual machines and still couldn't trigger the deadlock here. (I actually hope my hypothesis is wrong and this build still freezes for you... in which case please send a dump with the new build!)
EDIT: "Better" fix:
https://ci.appveyor.com/project/cfil...5dip/artifacts