From a07c0dd20ed878f0b680301efe4a1389be54f8af 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 3b24fbdbf..c7ff264cb 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -434,4 +434,9 @@ public class PaperWorldConfig {
         this.armorStandTick = this.getBoolean("armor-stands-tick", this.armorStandTick);
         log("ArmorStand ticking is " + (this.armorStandTick ? "enabled" : "disabled") + " by default");
     }
+
+    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 a814d8cae..b0fd4d800 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -348,6 +348,13 @@ 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);
@@ -892,9 +899,9 @@ 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;
@@ -933,6 +940,12 @@ 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;
-- 
2.23.0