1 files changed, 27 insertions, 0 deletions
diff --git a/patches/server/0484-Prevent-headless-pistons-from-being-created.patch b/patches/server/0484-Prevent-headless-pistons-from-being-created.patch
new file mode 100644
index 0000000000..b31a2a9b3a
--- /dev/null
+++ b/patches/server/0484-Prevent-headless-pistons-from-being-created.patch
@@ -0,0 +1,27 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: commandblockguy <[email protected]>
+Date: Fri, 14 Aug 2020 14:44:14 -0500
+Subject: [PATCH] Prevent headless pistons from being created
+
+Prevent headless pistons from being created by explosions or tree/mushroom growth.
+
+diff --git a/src/main/java/net/minecraft/world/level/Explosion.java b/src/main/java/net/minecraft/world/level/Explosion.java
+index b18b0e1b5e059f08fd3117eaa0fb28a10fac6562..01477e7240f9e33d08d416a7d40ee10f3e5d4abf 100644
+--- a/src/main/java/net/minecraft/world/level/Explosion.java
++++ b/src/main/java/net/minecraft/world/level/Explosion.java
+@@ -187,6 +187,15 @@ public class Explosion {
+ 
+                             if (f > 0.0F && this.damageCalculator.shouldBlockExplode(this, this.level, blockposition, iblockdata, f)) {
+                                 set.add(blockposition);
++                                // Paper start - prevent headless pistons from forming
++                                if (!io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowHeadlessPistons && iblockdata.getBlock() == Blocks.MOVING_PISTON) {
++                                    BlockEntity extension = this.level.getBlockEntity(blockposition);
++                                    if (extension instanceof net.minecraft.world.level.block.piston.PistonMovingBlockEntity blockEntity && blockEntity.isSourcePiston()) {
++                                       net.minecraft.core.Direction direction = iblockdata.getValue(net.minecraft.world.level.block.piston.PistonHeadBlock.FACING);
++                                       set.add(blockposition.relative(direction.getOpposite()));
++                                    }
++                                }
++                                // Paper end
+                             }
+ 
+                             d4 += d0 * 0.30000001192092896D;