From 252d777181440ac9c14bbbb85a26bcc42f498fb2 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 319b5b95d..897bb49b4 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -593,4 +593,10 @@ public class PaperWorldConfig {
         this.villageSiegesEnabled = getBoolean("game-mechanics.village-sieges-enabled", this.villageSiegesEnabled);
         log("Village sieges are " + (this.villageSiegesEnabled ? "enabled" : "disabled"));
     }
+
+    public boolean preventMovingIntoUnloadedChunks = false;
+    private void preventMovingIntoUnloadedChunks() {
+        preventMovingIntoUnloadedChunks = getBoolean("prevent-moving-into-unloaded-chunks", false);
+        log("Prevent players from moving into unloaded chunks: " + (this.preventMovingIntoUnloadedChunks ? "enabled" : "disabled"));
+    }
 }
diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 8c20bcd14..59d526329 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -343,6 +343,13 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
                 }
                 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.isChunkLoaded((int) Math.floor(packetplayinvehiclemove.getX()) >> 4, (int) Math.floor(packetplayinvehiclemove.getZ()) >> 4, false)) {
+                    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.minecraftServer.R() || !this.minecraftServer.Q().equals(entity.getName()))) { // Spigot
                 // CraftBukkit end
                     PlayerConnection.LOGGER.warn("{} (vehicle of {}) moved too quickly! {},{},{}", entity.getName(), this.player.getName(), Double.valueOf(d6), Double.valueOf(d7), Double.valueOf(d8));
@@ -539,9 +546,9 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
                         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;
@@ -581,6 +588,13 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
                                 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, false)) {
+                                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.L() && (!this.player.x().getGameRules().getBoolean("disableElytraMovementCheck") || !this.player.cP())) {
                                 float f2 = this.player.cP() ? 300.0F : 100.0F;
 
-- 
2.21.0