Paper/patches/server/0293-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 315dad4789f5f2582ee9b4fc176affd1f57537ef..482eebf61944add9f1ad6abea6124a9f3191628e 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.getTypeIfLoaded(this.delayedDestroyPos); // Paper
+            if (iblockdata == null || iblockdata.isAir()) { // Paper
                 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 want to do same logic as above, return instead
+            iblockdata = this.level.getTypeIfLoaded(this.destroyPos);
+            if (iblockdata == null) {
+                this.isDestroyingBlock = false;
+                return;
+            }
+            // Paper end
             if (iblockdata.isAir()) {
                 this.level.destroyBlockProgress(this.player.getId(), this.destroyPos, -1);
                 this.lastSentState = -1;
@@ -161,6 +167,11 @@ public class ServerPlayerGameMode {
         double d1 = this.player.getY() - ((double) pos.getY() + 0.5D) + 1.5D;
         double d2 = this.player.getZ() - ((double) pos.getZ() + 0.5D);
         double d3 = d0 * d0 + d1 * d1 + d2 * d2;
+        // Paper start
+        this.handleBlockBreakAction(pos, action, direction, worldHeight, d3);
+    }
+    public void handleBlockBreakAction(BlockPos pos, ServerboundPlayerActionPacket.Action action, Direction direction, int worldHeight, double d3) {
+        // Paper end
 
         if (d3 > 36.0D) {
             this.player.connection.send(new ClientboundBlockBreakAckPacket(pos, this.level.getBlockState(pos), action, false, "too far"));
@@ -295,10 +306,12 @@ public class ServerPlayerGameMode {
                 this.player.connection.send(new ClientboundBlockBreakAckPacket(pos, this.level.getBlockState(pos), action, true, "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)) {
                     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.player.connection.send(new ClientboundBlockBreakAckPacket(this.destroyPos, this.level.getBlockState(this.destroyPos), action, true, "aborted mismatched destroying"));
+                    BlockState type = this.level.getTypeIfLoaded(this.destroyPos); // Paper - don't load unloaded chunks for stale records here
+                    if (type != null) this.level.destroyBlockProgress(this.player.getId(), this.destroyPos, -1); // Paper
+                    if (type != null) this.player.connection.send(new ClientboundBlockBreakAckPacket(this.destroyPos, type, action, true, "aborted mismatched destroying")); // Paper
+                    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 38a48add445e8dd6888bc5bb22e7bf5482682536..386412d651002c44742d3c87201d184885f2bd08 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1544,7 +1544,22 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
             case START_DESTROY_BLOCK:
             case ABORT_DESTROY_BLOCK:
             case STOP_DESTROY_BLOCK:
-                this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level.getMaxBuildHeight());
+                // Paper start - Don't allow digging in unloaded chunks
+                // Copied from ServerPlayerGameMode#handleBlockBreakAction
+                double d0 = this.player.getX() - ((double) blockposition.getX() + 0.5D);
+                double d1 = this.player.getY() - ((double) blockposition.getY() + 0.5D) + 1.5D;
+                double d2 = this.player.getZ() - ((double) blockposition.getZ() + 0.5D);
+                double blockDistanceSquared = d0 * d0 + d1 * d1 + d2 * d2;
+                if (blockDistanceSquared > 40 * 40) {
+                    LOGGER.warn("{} tried to break a block {} square blocks away from their position", this.player.getScoreboardName(), blockDistanceSquared);
+                    this.disconnect("Invalid block break distance");
+                    return;
+                }
+                if (this.player.level.getChunkIfLoadedImmediately(blockposition.getX() >> 4, blockposition.getZ() >> 4) == null) {
+                    return;
+                }
+                this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level.getMaxBuildHeight(), blockDistanceSquared);
+                // Paper end - Don't allow digging in unloaded chunks
                 return;
             default:
                 throw new IllegalArgumentException("Invalid player action");