In 25w09a stack separation stopped working. Here is a showcase video:
Expected behavior: (video below) Notice how pressure plate is triggered on the first game tick of the piston movement
Observed behavior: (video below) Notice how pressure plate is NOT triggered on the first game tick of the piston movement
This issue is caused by the absence of the Entity#applyEffectsFromBlocks call within the PistonMovingBlockEntity’s moveEntityByPiston() method. In the attached screenshot it shows the exact place where the call is missing.
Please note, that this is a very TMC-sensitive issue, as it breaks all of the redstone contraptions that relied on this mechanic, which includes all of the current TNT cannon tech, and basically every contraption that handles large quantities of entities in some way. Moreover, this issue causes the piston to pressure plate interaction timings to change, which also can break a bunch of stuff.
Linked issues
Attachments
Comments 7
This issue breaks stacked cart unstacking devices which are used in storage systems.
Example minecart unstacker:
There is no need to add confirmation comments to a report already confirmed by the community (note the Confirmation Status, which has been set to Community Consensus). These comments do not add any valuable information and unnecessarily flood the comments section. I’ve cleaned up the comments section a bit.
This also affects mobs being pushed by pistons while inside berry bushes. They do not take damage in 1.25.1-rc1 while they do take damage in 1.21.4.
[media]a correction related to Andrew S comment about cart unstackers beeing broken: the minecart unstacker that was linked and a couple other that i tested still work fine. same goes for item entity seperators. i was only able to replicate it for tnt and mobs
@theGlotzerify Minecarts are in fact not subject to this bug, but that is because they override the move method which handles the interactive collisions separately, all of the other entities are still very much subjected to this issue. I think you tested it wrong, because i can replicate the issue with item entitites.
Can confirm in 1.21.5 Release Candidate 1.