so i found this when seeing if iron trapdoors popped off if pushed by slimeblocks when in 1.8 and that was multiplayer but ive just tested (when i took the screenshots) in singleplayer and its still doing it but instead of popping off it stayed open (i do have an idea that keeps this ingame but a different way to do this) and if you remove the power source itll keep it open and it doesnt deactivate from block updates but heres my idea: if you use either shears or a stick or maybe slime ball it will lock the trapdoor like that until you use a torch or a water bucket on it if its slime or stick and redstone dust to reactivate it to be used again if you use shears but i like this glitch and it can be made into an actual update so it should stay but be fixed so you do this without a glitch and the images are set ups to it, right clicking the lever activates the glitch