From ded6f6bb7cc36b6a4e2ba2bca07c72b85cba1732 Mon Sep 17 00:00:00 2001
From: Eclipse <116838833+eclipseisoffline@users.noreply.github.com>
Date: Thu, 20 Jun 2024 14:46:54 +0000
Subject: [PATCH] Fix NPEs caused by custom head blocks from Polymer (#4764)

* Add null checks to fix NPEs caused by custom head blocks from Polymer

* Make sure block state is never null, remove now unnecessary null checks

* Remove unnecessary default fallback in skull block entity translator
---
 .../geyser/entity/type/player/SkullPlayerEntity.java   |  2 +-
 .../geysermc/geyser/level/block/type/BlockState.java   | 10 +++++++++-
 .../bedrock/entity/player/BedrockActionTranslator.java |  4 ++--
 .../java/level/JavaBlockDestructionTranslator.java     |  4 +---
 .../java/level/JavaBlockEntityDataTranslator.java      |  5 +----
 .../java/level/JavaLevelChunkWithLightTranslator.java  |  3 +--
 6 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/core/src/main/java/org/geysermc/geyser/entity/type/player/SkullPlayerEntity.java b/core/src/main/java/org/geysermc/geyser/entity/type/player/SkullPlayerEntity.java
index f2f93b266..1c5060de0 100644
--- a/core/src/main/java/org/geysermc/geyser/entity/type/player/SkullPlayerEntity.java
+++ b/core/src/main/java/org/geysermc/geyser/entity/type/player/SkullPlayerEntity.java
@@ -152,7 +152,7 @@ public class SkullPlayerEntity extends PlayerEntity {
                 case EAST -> x -= 0.24f;
             }
         } else {
-            rotation = (180f + (blockState.getValue(Properties.ROTATION_16) * 22.5f)) % 360;
+            rotation = (180f + blockState.getValue(Properties.ROTATION_16, 0) * 22.5f) % 360;
         }
 
         moveAbsolute(Vector3f.from(x, y, z), rotation, 0, rotation, true, true);
diff --git a/core/src/main/java/org/geysermc/geyser/level/block/type/BlockState.java b/core/src/main/java/org/geysermc/geyser/level/block/type/BlockState.java
index 7229e9e50..2513e3ceb 100644
--- a/core/src/main/java/org/geysermc/geyser/level/block/type/BlockState.java
+++ b/core/src/main/java/org/geysermc/geyser/level/block/type/BlockState.java
@@ -25,6 +25,7 @@
 
 package org.geysermc.geyser.level.block.type;
 
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.geysermc.geyser.level.block.property.Property;
 import org.geysermc.geyser.registry.BlockRegistries;
@@ -184,7 +185,14 @@ public final class BlockState {
         return builder.toString();
     }
 
+    /**
+     * Null-safe method that looks up a Java block state ID in the BLOCK_STATES registry, and defaults to air if not found.
+     *
+     * @param javaId the Java block state ID to look up.
+     * @return the corresponding block state, or air if the given ID wasn't registered and returned null.
+     */
+    @NonNull
     public static BlockState of(int javaId) {
-        return BlockRegistries.BLOCK_STATES.get(javaId);
+        return BlockRegistries.BLOCK_STATES.getOrDefault(javaId, BlockRegistries.BLOCK_STATES.get(Block.JAVA_AIR_ID));
     }
 }
diff --git a/core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/entity/player/BedrockActionTranslator.java b/core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/entity/player/BedrockActionTranslator.java
index 959797d41..6834d3190 100644
--- a/core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/entity/player/BedrockActionTranslator.java
+++ b/core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/entity/player/BedrockActionTranslator.java
@@ -160,7 +160,7 @@ public class BedrockActionTranslator extends PacketTranslator<PlayerActionPacket
                 LevelEventPacket startBreak = new LevelEventPacket();
                 startBreak.setType(LevelEvent.BLOCK_START_BREAK);
                 startBreak.setPosition(vector.toFloat());
-                double breakTime = BlockUtils.getSessionBreakTime(session, BlockRegistries.BLOCK_STATES.getOrDefault(blockState, BlockState.of(Block.JAVA_AIR_ID)).block()) * 20;
+                double breakTime = BlockUtils.getSessionBreakTime(session, BlockState.of(blockState).block()) * 20;
 
                 // If the block is custom or the breaking item is custom, we must keep track of break time ourselves
                 GeyserItemStack item = session.getPlayerInventory().getItemInHand();
@@ -211,7 +211,7 @@ public class BedrockActionTranslator extends PacketTranslator<PlayerActionPacket
                 LevelEventPacket updateBreak = new LevelEventPacket();
                 updateBreak.setType(LevelEvent.BLOCK_UPDATE_BREAK);
                 updateBreak.setPosition(vectorFloat);
-                double breakTime = BlockUtils.getSessionBreakTime(session, BlockRegistries.BLOCK_STATES.getOrDefault(breakingBlock, BlockState.of(Block.JAVA_AIR_ID)).block()) * 20;
+                double breakTime = BlockUtils.getSessionBreakTime(session, BlockState.of(breakingBlock).block()) * 20;
 
 
                 // If the block is custom, we must keep track of when it should break ourselves
diff --git a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockDestructionTranslator.java b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockDestructionTranslator.java
index 700f7e701..674a1c583 100644
--- a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockDestructionTranslator.java
+++ b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockDestructionTranslator.java
@@ -27,9 +27,7 @@ package org.geysermc.geyser.translator.protocol.java.level;
 
 import org.cloudburstmc.protocol.bedrock.data.LevelEvent;
 import org.cloudburstmc.protocol.bedrock.packet.LevelEventPacket;
-import org.geysermc.geyser.level.block.type.Block;
 import org.geysermc.geyser.level.block.type.BlockState;
-import org.geysermc.geyser.registry.BlockRegistries;
 import org.geysermc.geyser.registry.type.ItemMapping;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
@@ -43,7 +41,7 @@ public class JavaBlockDestructionTranslator extends PacketTranslator<Clientbound
     @Override
     public void translate(GeyserSession session, ClientboundBlockDestructionPacket packet) {
         int state = session.getGeyser().getWorldManager().getBlockAt(session, packet.getPosition().getX(), packet.getPosition().getY(), packet.getPosition().getZ());
-        int breakTime = (int) (65535 / Math.ceil(BlockUtils.getBreakTime(session, BlockRegistries.BLOCK_STATES.getOrDefault(state, BlockState.of(Block.JAVA_AIR_ID)).block(), ItemMapping.AIR, null, false) * 20));
+        int breakTime = (int) (65535 / Math.ceil(BlockUtils.getBreakTime(session, BlockState.of(state).block(), ItemMapping.AIR, null, false) * 20));
         LevelEventPacket levelEventPacket = new LevelEventPacket();
         levelEventPacket.setPosition(packet.getPosition().toFloat());
         levelEventPacket.setType(LevelEvent.BLOCK_START_BREAK);
diff --git a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockEntityDataTranslator.java b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockEntityDataTranslator.java
index 24d419c24..c13180e27 100644
--- a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockEntityDataTranslator.java
+++ b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockEntityDataTranslator.java
@@ -33,9 +33,7 @@ import org.cloudburstmc.protocol.bedrock.data.structure.StructureMirror;
 import org.cloudburstmc.protocol.bedrock.data.structure.StructureRotation;
 import org.cloudburstmc.protocol.bedrock.packet.ContainerOpenPacket;
 import org.cloudburstmc.protocol.bedrock.packet.UpdateBlockPacket;
-import org.geysermc.geyser.level.block.Blocks;
 import org.geysermc.geyser.level.block.type.BlockState;
-import org.geysermc.geyser.registry.BlockRegistries;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.level.block.entity.BlockEntityTranslator;
 import org.geysermc.geyser.translator.level.block.entity.SkullBlockEntityTranslator;
@@ -59,8 +57,7 @@ public class JavaBlockEntityDataTranslator extends PacketTranslator<ClientboundB
         BlockEntityTranslator translator = BlockEntityUtils.getBlockEntityTranslator(type);
         // The Java block state is used in BlockEntityTranslator.translateTag() to make up for some inconsistencies
         // between Java block states and Bedrock block entity data
-        BlockState blockState = BlockRegistries.BLOCK_STATES.getOrDefault(session.getGeyser().getWorldManager().getBlockAt(session, packet.getPosition()),
-                Blocks.AIR.defaultBlockState());
+        BlockState blockState = session.getGeyser().getWorldManager().blockAt(session, packet.getPosition());
 
         if (blockState.block().blockEntityType() != type) {
             return;
diff --git a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java
index 9d175f653..b6bb1c0c6 100644
--- a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java
+++ b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java
@@ -39,7 +39,6 @@ import org.cloudburstmc.protocol.bedrock.data.definitions.BlockDefinition;
 import org.cloudburstmc.protocol.bedrock.packet.LevelChunkPacket;
 import org.geysermc.geyser.entity.type.ItemFrameEntity;
 import org.geysermc.geyser.level.BedrockDimension;
-import org.geysermc.geyser.level.block.Blocks;
 import org.geysermc.geyser.level.block.type.Block;
 import org.geysermc.geyser.level.block.type.BlockState;
 import org.geysermc.geyser.level.chunk.BlockStorage;
@@ -399,7 +398,7 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
 
                 // Get the Java block state ID from block entity position
                 DataPalette section = javaChunks[(y >> 4) - yOffset];
-                BlockState blockState = BlockRegistries.BLOCK_STATES.getOrDefault(section.get(x, y & 0xF, z), Blocks.AIR.defaultBlockState());
+                BlockState blockState = BlockState.of(section.get(x, y & 0xF, z));
 
                 // Note that, since 1.20.5, tags can be null, but Bedrock still needs a default tag to render the item
                 // Also, some properties - like banner base colors - are part of the tag and is processed here.