From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Gabriele C <sgdc3.mail@gmail.com>
Date: Mon, 22 Oct 2018 17:34:10 +0200
Subject: [PATCH] Add option to prevent players from moving into unloaded
 chunks #1551


diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 37bd28f18d3f48767d8141bde3395b8443d5650a..a73b88d51608ce94f6e4c9013c8c4de97523fe42 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -400,4 +400,9 @@ public class PaperWorldConfig {
         waterOverLavaFlowSpeed = getInt("water-over-lava-flow-speed", 5);
         log("Water over lava flow speed: " + waterOverLavaFlowSpeed);
     }
+
+    public boolean preventMovingIntoUnloadedChunks = false;
+    private void preventMovingIntoUnloadedChunks() {
+        preventMovingIntoUnloadedChunks = getBoolean("prevent-moving-into-unloaded-chunks", false);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index d33657d94a4e9c6563fbc7826e18624528c498f5..b1bad421650a8c93cdc38d1f4f83ab1c39e2f624 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -350,6 +350,13 @@ public class PlayerConnection implements PacketListenerPlayIn {
                 }
                 speed *= 2f; // TODO: Get the speed of the vehicle instead of the player
 
+                // Paper start - Prevent moving into unloaded chunks
+                if (player.world.paperConfig.preventMovingIntoUnloadedChunks && worldserver.getChunkIfLoadedImmediately((int) Math.floor(packetplayinvehiclemove.getX()) >> 4, (int) Math.floor(packetplayinvehiclemove.getZ()) >> 4) == null) {
+                    this.networkManager.sendPacket(new PacketPlayOutVehicleMove(entity));
+                    return;
+                }
+                // Paper end
+
                 if (d10 - d9 > Math.max(100.0D, Math.pow((double) (org.spigotmc.SpigotConfig.movedTooQuicklyMultiplier * (float) i * speed), 2)) && !this.isExemptPlayer()) {
                 // CraftBukkit end
                     PlayerConnection.LOGGER.warn("{} (vehicle of {}) moved too quickly! {},{},{}", entity.getDisplayName().getString(), this.player.getDisplayName().getString(), d6, d7, d8);
@@ -919,9 +926,9 @@ public class PlayerConnection implements PacketListenerPlayIn {
                         double d1 = this.player.locY();
                         double d2 = this.player.locZ();
                         double d3 = this.player.locY();
-                        double d4 = packetplayinflying.a(this.player.locX());
+                        double d4 = packetplayinflying.a(this.player.locX());double toX = d4; // Paper - OBFHELPER
                         double d5 = packetplayinflying.b(this.player.locY());
-                        double d6 = packetplayinflying.c(this.player.locZ());
+                        double d6 = packetplayinflying.c(this.player.locZ());double toZ = d6; // Paper - OBFHELPER
                         float f = packetplayinflying.a(this.player.yaw);
                         float f1 = packetplayinflying.b(this.player.pitch);
                         double d7 = d4 - this.l;
@@ -960,6 +967,12 @@ public class PlayerConnection implements PacketListenerPlayIn {
                             } else {
                                 speed = player.abilities.walkSpeed * 10f;
                             }
+                            // Paper start - Prevent moving into unloaded chunks
+                            if (player.world.paperConfig.preventMovingIntoUnloadedChunks && (this.player.locX() != toX || this.player.locZ() != toZ) && !worldserver.isChunkLoaded((int) Math.floor(toX) >> 4, (int) Math.floor(toZ) >> 4)) {
+                                this.internalTeleport(this.player.locX(), this.player.locY(), this.player.locZ(), this.player.yaw, this.player.pitch, Collections.emptySet());
+                                return;
+                            }
+                            // Paper end
 
                             if (!this.player.H() && (!this.player.getWorldServer().getGameRules().getBoolean(GameRules.DISABLE_ELYTRA_MOVEMENT_CHECK) || !this.player.isGliding())) {
                                 float f2 = this.player.isGliding() ? 300.0F : 100.0F;