From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Zach Brown <zach.brown@destroystokyo.com>
Date: Sun, 22 May 2016 20:20:55 -0500
Subject: [PATCH] Optional TNT doesn't move in water


diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index eb04fdb172a50ec1f5b7fe78fa0e7655246abd60..9b2e9a02ff31c3cb37b67135d0a03441f247d8e2 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -291,4 +291,14 @@ public class PaperWorldConfig {
             );
         }
     }
+
+    public boolean preventTntFromMovingInWater;
+    private void preventTntFromMovingInWater() {
+        if (PaperConfig.version < 13) {
+            boolean oldVal = getBoolean("enable-old-tnt-cannon-behaviors", false);
+            set("prevent-tnt-from-moving-in-water", oldVal);
+        }
+        preventTntFromMovingInWater = getBoolean("prevent-tnt-from-moving-in-water", false);
+        log("Prevent TNT from moving in water: " + preventTntFromMovingInWater);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index ac57bfb00edd9268e89a7fd7cea36097d61d6951..ad9bbda31a4cdb306ca40f2b99e4b815c4f136bd 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -68,7 +68,7 @@ public class ServerEntity {
     private boolean wasRiding;
     private boolean wasOnGround;
     // CraftBukkit start
-    private final Set<ServerPlayerConnection> trackedPlayers;
+    final Set<ServerPlayerConnection> trackedPlayers; // Paper - private -> package
 
     public ServerEntity(ServerLevel worldserver, Entity entity, int i, boolean flag, Consumer<Packet<?>> consumer, Set<ServerPlayerConnection> trackedPlayers) {
         this.trackedPlayers = trackedPlayers;
diff --git a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
index abc62c560816d945642d830a020deb28ff2efa37..5a16de4f080c31d6e278363fd1d3e23d48be3db5 100644
--- a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
+++ b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
@@ -97,6 +97,27 @@ public class PrimedTnt extends Entity {
             }
         }
 
+        // Paper start - Optional prevent TNT from moving in water
+        if (!this.isRemoved() && this.wasTouchingWater && this.level.paperConfig.preventTntFromMovingInWater) {
+            /*
+             * Author: Jedediah Smith <jedediah@silencegreys.com>
+             */
+            // Send position and velocity updates to nearby players on every tick while the TNT is in water.
+            // This does pretty well at keeping their clients in sync with the server.
+            net.minecraft.server.level.ChunkMap.TrackedEntity ete = ((net.minecraft.server.level.ServerLevel)this.level).getChunkSource().chunkMap.entityMap.get(this.getId());
+            if (ete != null) {
+                net.minecraft.network.protocol.game.ClientboundSetEntityMotionPacket velocityPacket = new net.minecraft.network.protocol.game.ClientboundSetEntityMotionPacket(this);
+                net.minecraft.network.protocol.game.ClientboundTeleportEntityPacket positionPacket = new net.minecraft.network.protocol.game.ClientboundTeleportEntityPacket(this);
+
+                ete.seenBy.stream()
+                    .filter(viewer -> (viewer.getPlayer().getX() - this.getX()) * (viewer.getPlayer().getY() - this.getY()) * (viewer.getPlayer().getZ() - this.getZ()) < 16 * 16)
+                    .forEach(viewer -> {
+                        viewer.send(velocityPacket);
+                        viewer.send(positionPacket);
+                    });
+            }
+        }
+        // Paper end
     }
 
     private void explode() {
@@ -152,4 +173,11 @@ public class PrimedTnt extends Entity {
     public Packet<?> getAddEntityPacket() {
         return new ClientboundAddEntityPacket(this);
     }
+
+    // Paper start - Optional prevent TNT from moving in water
+    @Override
+    public boolean isPushedByFluid() {
+        return !level.paperConfig.preventTntFromMovingInWater && super.isPushedByFluid();
+    }
+    // Paper end
 }