I have OS X set to require my password immediately after “sleep or screen saver begins” (and I'm assuming this includes display sleep). Since Mavericks, there seems to be a one-second grace period: if I trigger the screen saver or put the display to sleep, and then immediately hit the shift key or move the mouse, I'm dropped back into my account with no password prompt.
I'm currently running Yosemite.0 (
10.10.0). Is this a bug in Mavericks that never got fixed, or what? More importantly, how do I get it to require my password immediately?