An idle timeout of zero no longer locks the session at once
Setting the screensaver or the lock timeout to zero, to turn that action off, could lock the session as soon as an app stopped blocking idle. Pull request 12538 merged into quattro.
Zero was passed into the idle monitor as a real deadline. When a game or another app released its idle inhibitor, the monitor treated the session as already idle.
Zero is now disabled. If both timeouts are zero, the monitor stays off. The GitHub user paulogeyer opened pull request 12538, and David Heinemeier Hansson merged it.