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/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index fb16216b54eea81fceaf3edafa69b554ad01c807..90d2fa5b90d64ddb28075a50f4478b464a29a285 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -73,7 +73,7 @@ public class ServerEntity {
     @Nullable
     private List<SynchedEntityData.DataValue<?>> trackedDataValues;
     // 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 5c3b86e2301079e775971aa4da6a8f2dc6a40d1f..d9ed22e9853eebdf6c517b41787a27a1a56a0871 100644
--- a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
+++ b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
@@ -106,6 +106,27 @@ public class PrimedTnt extends Entity implements TraceableEntity {
             }
         }
 
+        // Paper start - Optional prevent TNT from moving in water
+        if (!this.isRemoved() && this.wasTouchingWater && this.level().paperConfig().fixes.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() {
@@ -179,4 +200,11 @@ public class PrimedTnt extends Entity implements TraceableEntity {
     public BlockState getBlockState() {
         return (BlockState) this.entityData.get(PrimedTnt.DATA_BLOCK_STATE_ID);
     }
+
+    // Paper start - Optional prevent TNT from moving in water
+    @Override
+    public boolean isPushedByFluid() {
+        return !level().paperConfig().fixes.preventTntFromMovingInWater && super.isPushedByFluid();
+    }
+    // Paper end
 }