Paper/patches/server/0271-Don-t-allow-digging-into-unloaded-chunks.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 11 Nov 2018 21:01:09 +0000
Subject: [PATCH] Don't allow digging into unloaded chunks


diff --git a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
index a8d33286832786031ac57e6ce27d5181e1a3d9b1..e8b12b27e5ec74afb940f575e5ce78e5905d55f4 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
@@ -119,8 +119,8 @@ public class ServerPlayerGameMode {
         BlockState iblockdata;
 
         if (this.hasDelayedDestroy) {
-            iblockdata = this.level.getBlockState(this.delayedDestroyPos);
-            if (iblockdata.isAir()) {
+            iblockdata = this.level.getBlockStateIfLoaded(this.delayedDestroyPos); // Paper - Don't allow digging into unloaded chunks
+            if (iblockdata == null || iblockdata.isAir()) { // Paper - Don't allow digging into unloaded chunks
                 this.hasDelayedDestroy = false;
             } else {
                 float f = this.incrementDestroyProgress(iblockdata, this.delayedDestroyPos, this.delayedTickStart);
@@ -131,7 +131,13 @@ public class ServerPlayerGameMode {
                 }
             }
         } else if (this.isDestroyingBlock) {
-            iblockdata = this.level.getBlockState(this.destroyPos);
+            // Paper start - Don't allow digging into unloaded chunks; don't want to do same logic as above, return instead
+            iblockdata = this.level.getBlockStateIfLoaded(this.destroyPos);
+            if (iblockdata == null) {
+                this.isDestroyingBlock = false;
+                return;
+            }
+            // Paper end - Don't allow digging into unloaded chunks
             if (iblockdata.isAir()) {
                 this.level.destroyBlockProgress(this.player.getId(), this.destroyPos, -1);
                 this.lastSentState = -1;
@@ -160,6 +166,7 @@ public class ServerPlayerGameMode {
 
     public void handleBlockBreakAction(BlockPos pos, ServerboundPlayerActionPacket.Action action, Direction direction, int worldHeight, int sequence) {
         if (this.player.getEyePosition().distanceToSqr(Vec3.atCenterOf(pos)) > ServerGamePacketListenerImpl.MAX_INTERACTION_DISTANCE) {
+            if (true) return; // Paper - Don't allow digging into unloaded chunks; Don't notify if unreasonably far away
             this.debugLogging(pos, false, sequence, "too far");
         } else if (pos.getY() >= worldHeight) {
             this.player.connection.send(new ClientboundBlockUpdatePacket(pos, this.level.getBlockState(pos)));
@@ -299,10 +306,12 @@ public class ServerPlayerGameMode {
                 this.debugLogging(pos, true, sequence, "stopped destroying");
             } else if (action == ServerboundPlayerActionPacket.Action.ABORT_DESTROY_BLOCK) {
                 this.isDestroyingBlock = false;
-                if (!Objects.equals(this.destroyPos, pos)) {
+                if (!Objects.equals(this.destroyPos, pos) && !BlockPos.ZERO.equals(this.destroyPos)) { // Paper
                     ServerPlayerGameMode.LOGGER.debug("Mismatch in destroy block pos: {} {}", this.destroyPos, pos); // CraftBukkit - SPIGOT-5457 sent by client when interact event cancelled
-                    this.level.destroyBlockProgress(this.player.getId(), this.destroyPos, -1);
-                    this.debugLogging(pos, true, sequence, "aborted mismatched destroying");
+                    BlockState type = this.level.getBlockStateIfLoaded(this.destroyPos); // Paper - don't load unloaded chunks for stale records here
+                    if (type != null) this.level.destroyBlockProgress(this.player.getId(), this.destroyPos, -1);
+                    if (type != null) this.debugLogging(pos, true, sequence, "aborted mismatched destroying");
+                    this.destroyPos = BlockPos.ZERO; // Paper
                 }
 
                 this.level.destroyBlockProgress(this.player.getId(), pos, -1);
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 0d9251ceb351b7d763420c49b0bf487907c42c55..358b6b493af3fcc52b274ccc43a18187b505e1f0 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1590,6 +1590,12 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
             case START_DESTROY_BLOCK:
             case ABORT_DESTROY_BLOCK:
             case STOP_DESTROY_BLOCK:
+                // Paper start - Don't allow digging into unloaded chunks
+                if (this.player.level().getChunkIfLoadedImmediately(blockposition.getX() >> 4, blockposition.getZ() >> 4) == null) {
+                    this.player.connection.ackBlockChangesUpTo(packet.getSequence());
+                    return;
+                }
+                // Paper end - Don't allow digging into unloaded chunks
                 this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level().getMaxBuildHeight(), packet.getSequence());
                 this.player.connection.ackBlockChangesUpTo(packet.getSequence());
                 return;