The Bug
Powering off a lever that is powering a piston, and then repowering it in the next redstone tick BUD-powers the piston.
How to Reproduce
Place down a sticky piston. Now, attach a lever on the back of the piston and extend it by flicking the lever. On the piston, put an L-shape of slime blocks on the piston - a slime block, a slime block below that, and then a slime block in front (relative to the piston) of that slime block. To finish, place a rail - any type - on top of the farthest slime block from the piston. With my testing, you can add whatever you want to what that piston is pushing (like a TNT duper). Just make sure you have that L-shape and rail. Now, flick the lever off, and then on as quickly as possible. If done correctly, the lever should be on, but the piston should not be extended. As per how BUD-powering works, updating the piston makes it realize it's powered and extend.
Attachments
Comments 11
Done. (well, I uploaded a video, but same difference)
I found out that this bug is stranger than I originally thought.
This bug only happens, as far as my testing goes, when the piston is pushing at least an L-shape of slime blocks, with the farthest slime block having any type of rail on it. I show in the video how just a piston pushing a rail and a slime block doesn't work, just a sticky piston, and even just a regular piston. However, just the L-shape of slime blocks with the rail on top, a TNT duper, and more that include that L-shape produce the bug.
I'll update this report with this new information.
this is a normal behaviour,in the row in front of the piston,the last block that updates the piston is the one just in front,and the last block the turn into a block is the last of the row,so that will happen if you have 2 block directly in front of the piston and you repower it before it fully retracted.This is used in many bud switches and other contraptions
Are you still able to reproduce this in the latest version? I am unable to:
Note: Even using the '/tick' command to ensure I can as accurate timing as I can, I get the same results.
You need to leave the lever in the on state, not the off state. Power it, and un- and re-power it very quickly in a row. According to this report it should then stay retracted, and get BUD-ed.
Make sure you're doing the test right before saying you cannot confirm. 🙂
Did your title screen say Minecraft or Minecraft Java Edition?