I ask this since when moving soldiers directly in front of a door, no Shield icon shows up that would let you know how much cover you have. I know that alien troops can aimbot you and know where you are EVEN if the door is closed, but so far, they've missed every single shot against a soldier posted right behind a door.
Does this mean I'm on to something? Doors take a move action to be opened and closed, so I'm wondering if the door made any impact on me dodging bullets, or does it not matter what state the door is in, and I simply got lucky?