From 8a8266685fcae04ff147307be88cb5a79083572e Mon Sep 17 00:00:00 2001 From: Spottedleaf Date: Thu, 11 Jun 2020 17:29:42 -0700 Subject: [PATCH] PaperPR - Fix piston physics inconsistency Pistons invoke physics when they move blocks. The physics can cause tnt blocks to ignite. However, pistons (when storing the blocks they "moved") don't actually go back to the world state sometimes to check if something like that happened. As a result they end up moving the tnt like it was never ignited. This resulted in the ability to create machines that can duplicate tnt, called "world eaters". This patch makes the piston logic retrieve the block state from the world prevent this from occuring. Tested against the following tnt duper design: https://www.youtube.com/watch?v=mS7xxNGhjxs This patch also affects every type of machine that utilises this mechanic. For example, dead coral is removed by a physics update when being moved while it is attached to slimeblocks. Standard piston machines that don't destroy or modify the blocks they move by physics updates should be entirely unaffected. --- src/main/java/net/minecraft/server/BlockPiston.java | 4 ++-- src/main/java/net/minecraft/server/TileEntityPiston.java | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/main/java/net/minecraft/server/BlockPiston.java b/src/main/java/net/minecraft/server/BlockPiston.java index 1e72b3bbc5..fbcc016941 100644 --- a/src/main/java/net/minecraft/server/BlockPiston.java +++ b/src/main/java/net/minecraft/server/BlockPiston.java @@ -374,11 +374,11 @@ public class BlockPiston extends BlockDirectional { for (k = list.size() - 1; k >= 0; --k) { blockposition3 = (BlockPosition) list.get(k); - iblockdata1 = world.getType(blockposition3); + iblockdata1 = world.getType(blockposition3); map.replace(blockposition3, iblockdata1); // Purpur - fix piston physics inconsistency blockposition3 = blockposition3.shift(enumdirection1); map.remove(blockposition3); world.setTypeAndData(blockposition3, (IBlockData) Blocks.MOVING_PISTON.getBlockData().set(BlockPiston.FACING, enumdirection), 68); - world.setTileEntity(blockposition3, BlockPistonMoving.a((IBlockData) list1.get(k), enumdirection, flag, false)); + world.setTileEntity(blockposition3, BlockPistonMoving.a(iblockdata1, enumdirection, flag, false)); // Purpur - fix piston physics inconsistency --j; aiblockdata[j] = iblockdata1; } diff --git a/src/main/java/net/minecraft/server/TileEntityPiston.java b/src/main/java/net/minecraft/server/TileEntityPiston.java index 79df42f5e5..00608d09b7 100644 --- a/src/main/java/net/minecraft/server/TileEntityPiston.java +++ b/src/main/java/net/minecraft/server/TileEntityPiston.java @@ -137,7 +137,7 @@ public class TileEntityPiston extends TileEntity implements ITickable { private static void a(EnumDirection enumdirection, Entity entity, double d0, EnumDirection enumdirection1) { TileEntityPiston.h.set(enumdirection); entity.move(EnumMoveType.PISTON, new Vec3D(d0 * (double) enumdirection1.getAdjacentX(), d0 * (double) enumdirection1.getAdjacentY(), d0 * (double) enumdirection1.getAdjacentZ())); - TileEntityPiston.h.set((Object) null); + TileEntityPiston.h.set(null); // Purpur - decompile error } private void g(float f) { @@ -275,7 +275,7 @@ public class TileEntityPiston extends TileEntity implements ITickable { IBlockData iblockdata = Block.b(this.a, (GeneratorAccess) this.world, this.position); if (iblockdata.isAir()) { - this.world.setTypeAndData(this.position, this.a, 84); + this.world.setTypeAndData(this.position, this.a, 84 | 2); // Purpur - force notify (flag 2), it's possible the set type by the piston block (which doesn't notify) set this block to air Block.a(this.a, iblockdata, this.world, this.position, 3); } else { if (iblockdata.b((IBlockState) BlockProperties.C) && (Boolean) iblockdata.get(BlockProperties.C)) { -- 2.26.2