I was about to build a contraption to "mark" full chests with a lit redstone lamp, when I encountered this:
If you put any piston facing upwards, put a redstone block on it and extend the piston with a lever or button (or any otehr edstone signal), the piston will not retract anymore.
160th Duplicate of MC-108, please use the search function to see if your bug has already been submitted. Currently over 54% of tickets are being closed as duplicate.