Fix carpet and rail duping by pistons under same TNT duping config

This renames the config from enable tnt duping to enable piston duping

Normally we would not have a config for rails and carpet duping, but
the fix for TNT is the same fix for rails and carpet, so they are
having to be covered under that same config.

1 files changed, 33 insertions, 12 deletions

diff --git a/Spigot-Server-Patches/0542-Fix-piston-physics-inconsistency-MC-188840.patch b/Spigot-Server-Patches/0542-Fix-piston-physics-inconsistency-MC-188840.patch
index 8f9ad2edd8..21338460af 100644
--- a/Spigot-Server-Patches/0542-Fix-piston-physics-inconsistency-MC-188840.patch
+++ b/Spigot-Server-Patches/0542-Fix-piston-physics-inconsistency-MC-188840.patch
@@ -12,6 +12,10 @@ that can duplicate tnt, called "world eaters".
 This patch makes the piston logic retrieve the block state from the world
 prevent this from occuring.
 
+This patch also sets the moved pos to air immediately after creating
+the moving piston TE. This prevents the block from being updated from
+other physics calls by the piston.
+
 Tested against the following tnt duper design:
 https://www.youtube.com/watch?v=mS7xxNGhjxs
 
@@ -25,39 +29,56 @@ unaffected.
 
 This patch fixes https://bugs.mojang.com/browse/MC-188840
 
+This patch also fixes rail duping and carpet duping.
+
 diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
-index f0284e81db3ab7c45018de2b446f2d8296df15c3..863bec74a6a0ee916b7db05687e588ae52eed4cd 100644
+index f0284e81db3ab7c45018de2b446f2d8296df15c3..8444819f071b13e98ba07032520016a664b7b9bc 100644
 --- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
 +++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
-@@ -442,4 +442,8 @@ public class PaperConfig {
+@@ -442,4 +442,9 @@ public class PaperConfig {
          consoleHasAllPermissions = getBoolean("settings.console-has-all-permissions", consoleHasAllPermissions);
      }
  
-+    public static boolean allowTntDuplication = false;
-+    private static void allowTntDuplication() {
-+        allowTntDuplication = getBoolean("settings.unsupported-settings.allow-tnt-duplication", allowTntDuplication);
++    public static boolean allowPistonDuplication;
++    private static void allowPistonDuplication() {
++        allowPistonDuplication = getBoolean("settings.unsupported-settings.allow-piston-duplication", config.getBoolean("settings.unsupported-settings.allow-tnt-duplication", false));
++        set("settings.unsupported-settings.allow-tnt-duplication", null);
 +    }
  }
 diff --git a/src/main/java/net/minecraft/server/BlockPiston.java b/src/main/java/net/minecraft/server/BlockPiston.java
-index b29525c40dc8e3ae747b8ddf5a3bd79b7cc0b792..32ff3f65cf9c2f9f4be1c1e78f5df555efe67b07 100644
+index 39cd8ab5925ceb9494e0ac910c73338c24ecda2c..f90ac88d33fb6e83eb7bf1e1432df14e452387ec 100644
 --- a/src/main/java/net/minecraft/server/BlockPiston.java
 +++ b/src/main/java/net/minecraft/server/BlockPiston.java
-@@ -364,11 +364,11 @@ public class BlockPiston extends BlockDirectional {
+@@ -376,12 +376,24 @@ public class BlockPiston extends BlockDirectional {
+             }
  
              for (k = list.size() - 1; k >= 0; --k) {
-                 blockposition3 = (BlockPosition) list.get(k);
+-                blockposition3 = (BlockPosition) list.get(k);
 -                iblockdata1 = world.getType(blockposition3);
-+                iblockdata1 = world.getType(blockposition3); if (!com.destroystokyo.paper.PaperConfig.allowTntDuplication) map.replace(blockposition3, iblockdata1); // Paper start - fix piston physics inconsistency
++                // Paper start - fix a variety of piston desync dupes
++                boolean allowDesync = com.destroystokyo.paper.PaperConfig.allowPistonDuplication;
++                BlockPosition oldPos = blockposition3 = (BlockPosition) list.get(k);
++                iblockdata1 = allowDesync ? world.getType(oldPos) : null;
++                // Paper end - fix a variety of piston desync dupes
                  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(com.destroystokyo.paper.PaperConfig.allowTntDuplication ? list1.get(k) : iblockdata1, enumdirection, flag, false)); // Paper - fix piston physics inconsistency
++                // Paper start - fix a variety of piston desync dupes
++                if (!allowDesync) {
++                    iblockdata1 = world.getType(oldPos);
++                    map.replace(oldPos, iblockdata1);
++                }
++                world.setTileEntity(blockposition3, BlockPistonMoving.a(allowDesync ? list1.get(k) : iblockdata1, enumdirection, flag, false));
++                if (!allowDesync) {
++                    world.setTypeAndData(oldPos, Blocks.AIR.getBlockData(), 4 | 16 | 1024); // set air to prevent later physics updates from seeing this block
++                }
++                // Paper end - fix a variety of piston desync dupes
                  --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 489175abd8e582a3c082364fec357c4f061a22d7..634e37843097cdb08bab3a800565b42a58dce1d8 100644
+index 489175abd8e582a3c082364fec357c4f061a22d7..d700e8281fe50b1c4131ac260ff6c0d0dd8412f0 100644
 --- a/src/main/java/net/minecraft/server/TileEntityPiston.java
 +++ b/src/main/java/net/minecraft/server/TileEntityPiston.java
 @@ -275,7 +275,7 @@ public class TileEntityPiston extends TileEntity implements ITickable {
@@ -65,7 +86,7 @@ index 489175abd8e582a3c082364fec357c4f061a22d7..634e37843097cdb08bab3a800565b42a
  
                  if (iblockdata.isAir()) {
 -                    this.world.setTypeAndData(this.position, this.a, 84);
-+                    this.world.setTypeAndData(this.position, this.a, 84 | (com.destroystokyo.paper.PaperConfig.allowTntDuplication ? 0 : 2)); // Paper - force notify (flag 2), it's possible the set type by the piston block (which doesn't notify) set this block to air
++                    this.world.setTypeAndData(this.position, this.a, com.destroystokyo.paper.PaperConfig.allowPistonDuplication ? 84 : (84 | 2)); // Paper - 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)) {