From a473c1fc4ba440d60d3c4931b99bc8e96cbf90c1 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 6db1312035..8cf3076f4e 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -2,7 +2,6 @@ package com.destroystokyo.paper;
 
 import java.util.List;
 
-import org.bukkit.Bukkit;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.spigotmc.SpigotWorldConfig;
 
@@ -289,4 +288,14 @@ 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/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 7b295f4673..1aade318ef 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -2719,6 +2719,12 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
 
     public boolean bM() {
+        // Paper start
+        return this.pushedByWater();
+    }
+
+    public boolean pushedByWater() {
+        // Paper end
         return true;
     }
 
diff --git a/src/main/java/net/minecraft/server/EntityTNTPrimed.java b/src/main/java/net/minecraft/server/EntityTNTPrimed.java
index 7f8b8f5a36..9c31edade2 100644
--- a/src/main/java/net/minecraft/server/EntityTNTPrimed.java
+++ b/src/main/java/net/minecraft/server/EntityTNTPrimed.java
@@ -80,7 +80,27 @@ public class EntityTNTPrimed extends Entity {
                 this.world.addParticle(Particles.SMOKE, this.locX(), this.locY() + 0.5D, this.locZ(), 0.0D, 0.0D, 0.0D);
             }
         }
-
+        // Paper start - Optional prevent TNT from moving in water
+        if (!this.dead && this.inWater && this.world.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.
+            PlayerChunkMap.EntityTracker ete = this.tracker;
+            if (ete != null) {
+                PacketPlayOutEntityVelocity velocityPacket = new PacketPlayOutEntityVelocity(this);
+                PacketPlayOutEntityTeleport positionPacket = new PacketPlayOutEntityTeleport(this);
+
+                ete.trackedPlayers.stream()
+                    .filter(viewer -> (viewer.locX() - this.locX()) * (viewer.locY() - this.locY()) * (viewer.locZ() - this.locZ()) < 16 * 16)
+                    .forEach(viewer -> {
+                        viewer.playerConnection.sendPacket(velocityPacket);
+                        viewer.playerConnection.sendPacket(positionPacket);
+                    });
+            }
+        }
+        // Paper end
     }
 
     private void explode() {
@@ -149,4 +169,11 @@ public class EntityTNTPrimed extends Entity {
     public Packet<?> L() {
         return new PacketPlayOutSpawnEntity(this);
     }
+
+    // Paper start - Optional prevent TNT from moving in water
+    @Override
+    public boolean pushedByWater() {
+        return !world.paperConfig.preventTntFromMovingInWater && super.pushedByWater();
+    }
+    // Paper end
 }
diff --git a/src/main/java/net/minecraft/server/EntityTrackerEntry.java b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
index a13fd9b340..3ff7a7b4a8 100644
--- a/src/main/java/net/minecraft/server/EntityTrackerEntry.java
+++ b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
@@ -36,7 +36,7 @@ public class EntityTrackerEntry {
     private boolean q;
     private boolean r;
     // CraftBukkit start
-    private final Set<EntityPlayer> trackedPlayers;
+    final Set<EntityPlayer> trackedPlayers; // Paper - private -> package
     // Paper start
     private java.util.Map<EntityPlayer, Boolean> trackedPlayerMap = null;
 
-- 
2.26.2