From 7415dcf70e1ac557c0d0f6d0e7f39ac0fbe85110 Mon Sep 17 00:00:00 2001
From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
Date: Sun, 3 Mar 2024 17:05:34 -0500
Subject: [PATCH] Allow enabling sand duping (#10191)

Because this exploit has been widely known for years and has not been fixed by Mojang, we decided that it was worth allowing people to toggle it on/off due to how easy it is to make it configurable.

It should be noted that this decision does not promise all future exploits will be configurable.
---
 .../Fix-dangerous-end-portal-logic.patch      | 10 +++---
 patches/server/Fix-sand-duping.patch          | 36 -------------------
 patches/server/Paper-config-files.patch       |  2 ++
 3 files changed, 8 insertions(+), 40 deletions(-)
 delete mode 100644 patches/server/Fix-sand-duping.patch

diff --git a/patches/server/Fix-dangerous-end-portal-logic.patch b/patches/server/Fix-dangerous-end-portal-logic.patch
index 8d1c3f46b0..25ce4925e5 100644
--- a/patches/server/Fix-dangerous-end-portal-logic.patch
+++ b/patches/server/Fix-dangerous-end-portal-logic.patch
@@ -55,7 +55,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
              }
  
              this.processPortalCooldown();
-+            this.tickEndPortal(); // Paper - make end portalling safe
++            if (!io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowUnsafeEndPortalTeleportation) this.tickEndPortal(); // Paper - make end portalling safe
          }
      }
  
@@ -74,12 +74,14 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 -            if (entity instanceof ServerPlayer) {
 -                ((ServerPlayer) entity).changeDimension(worldserver, PlayerTeleportEvent.TeleportCause.END_PORTAL);
 -                return;
--            }
--            // CraftBukkit end
--            entity.changeDimension(worldserver);
 +            // Paper start - move all of this logic into portal tick
 +            entity.portalWorld = ((ServerLevel)world);
 +            entity.portalBlock = pos.immutable();
++            if (io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowUnsafeEndPortalTeleportation) {
++                entity.tickEndPortal();
+             }
+-            // CraftBukkit end
+-            entity.changeDimension(worldserver);
 +            // Paper end - move all of this logic into portal tick
          }
  
diff --git a/patches/server/Fix-sand-duping.patch b/patches/server/Fix-sand-duping.patch
deleted file mode 100644
index c912504211..0000000000
--- a/patches/server/Fix-sand-duping.patch
+++ /dev/null
@@ -1,36 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Spottedleaf <Spottedleaf@users.noreply.github.com>
-Date: Fri, 12 Jun 2020 13:33:19 -0700
-Subject: [PATCH] Fix sand duping
-
-If the falling block dies during teleportation (entity#move), then we need
-to detect that by placing a check after the move.
-
-diff --git a/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java b/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
---- a/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
-+++ b/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
-@@ -0,0 +0,0 @@ public class FallingBlockEntity extends Entity {
- 
-     @Override
-     public void tick() {
-+        // Paper start - fix sand duping
-+        if (this.isRemoved()) {
-+            return;
-+        }
-+        // Paper end - fix sand duping
-         if (this.blockState.isAir()) {
-             this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
-         } else {
-@@ -0,0 +0,0 @@ public class FallingBlockEntity extends Entity {
-             }
- 
-             this.move(MoverType.SELF, this.getDeltaMovement());
-+            // Paper start - fix sand duping
-+            if (this.isRemoved()) {
-+                return;
-+            }
-+            // Paper end - fix sand duping
-             // Paper start - Configurable falling blocks height nerf
-             if (this.level().paperConfig().fixes.fallingBlockHeightNerf.test(v -> this.getY() > v)) {
-                 if (this.dropItem && this.level().getGameRules().getBoolean(GameRules.RULE_DOENTITYDROPS)) {
diff --git a/patches/server/Paper-config-files.patch b/patches/server/Paper-config-files.patch
index 3078a7bbfb..dde3415e5f 100644
--- a/patches/server/Paper-config-files.patch
+++ b/patches/server/Paper-config-files.patch
@@ -635,6 +635,8 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    public UnsupportedSettings unsupportedSettings;
 +
 +    public class UnsupportedSettings extends ConfigurationPart {
++        @Comment("This setting allows for exploits related to end portals, for example sand duping")
++        public boolean allowUnsafeEndPortalTeleportation = false;
 +        @Comment("This setting controls if players should be able to break bedrock, end portals and other intended to be permanent blocks.")
 +        public boolean allowPermanentBlockBreakExploits = false;
 +        @Comment("This setting controls if player should be able to use TNT duplication, but this also allows duplicating carpet, rails and potentially other items")