From 5670778f9aeb22af72cc15784a017043b949bb9e Mon Sep 17 00:00:00 2001
From: kuroppoi <68156848+kuroppoi@users.noreply.github.com>
Date: Sun, 9 May 2021 18:04:33 +0200
Subject: [PATCH] Default MessagePack enum values to prevent NPE

---
 .../gameserver/entity/FacingDirection.java        |  2 ++
 .../java/brainwine/gameserver/item/Layer.java     |  2 ++
 .../gameserver/msgpack/DefaultEnumValue.java      | 10 ++++++++++
 .../msgpack/templates/EnumTemplate.java           | 15 +++++++++++++--
 4 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 gameserver/src/main/java/brainwine/gameserver/msgpack/DefaultEnumValue.java

diff --git a/gameserver/src/main/java/brainwine/gameserver/entity/FacingDirection.java b/gameserver/src/main/java/brainwine/gameserver/entity/FacingDirection.java
index f0c4543..1620085 100644
--- a/gameserver/src/main/java/brainwine/gameserver/entity/FacingDirection.java
+++ b/gameserver/src/main/java/brainwine/gameserver/entity/FacingDirection.java
@@ -1,11 +1,13 @@
 package brainwine.gameserver.entity;
 
+import brainwine.gameserver.msgpack.DefaultEnumValue;
 import brainwine.gameserver.msgpack.EnumValue;
 import brainwine.gameserver.msgpack.RegisterEnum;
 
 @RegisterEnum
 public enum FacingDirection {
     
+    @DefaultEnumValue
     WEST(-1),
     EAST(1);
     
diff --git a/gameserver/src/main/java/brainwine/gameserver/item/Layer.java b/gameserver/src/main/java/brainwine/gameserver/item/Layer.java
index 48063c1..2656579 100644
--- a/gameserver/src/main/java/brainwine/gameserver/item/Layer.java
+++ b/gameserver/src/main/java/brainwine/gameserver/item/Layer.java
@@ -2,6 +2,7 @@ package brainwine.gameserver.item;
 
 import com.fasterxml.jackson.annotation.JsonEnumDefaultValue;
 
+import brainwine.gameserver.msgpack.DefaultEnumValue;
 import brainwine.gameserver.msgpack.RegisterEnum;
 
 @RegisterEnum
@@ -12,6 +13,7 @@ public enum Layer {
     FRONT,
     LIQUID,
     
+    @DefaultEnumValue
     @JsonEnumDefaultValue
     NONE;
 }
\ No newline at end of file
diff --git a/gameserver/src/main/java/brainwine/gameserver/msgpack/DefaultEnumValue.java b/gameserver/src/main/java/brainwine/gameserver/msgpack/DefaultEnumValue.java
new file mode 100644
index 0000000..8d4d35e
--- /dev/null
+++ b/gameserver/src/main/java/brainwine/gameserver/msgpack/DefaultEnumValue.java
@@ -0,0 +1,10 @@
+package brainwine.gameserver.msgpack;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.FIELD, ElementType.METHOD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface DefaultEnumValue {}
\ No newline at end of file
diff --git a/gameserver/src/main/java/brainwine/gameserver/msgpack/templates/EnumTemplate.java b/gameserver/src/main/java/brainwine/gameserver/msgpack/templates/EnumTemplate.java
index 3c5fc39..fd0fc9c 100644
--- a/gameserver/src/main/java/brainwine/gameserver/msgpack/templates/EnumTemplate.java
+++ b/gameserver/src/main/java/brainwine/gameserver/msgpack/templates/EnumTemplate.java
@@ -13,17 +13,28 @@ import org.msgpack.template.AbstractTemplate;
 import org.msgpack.type.ValueType;
 import org.msgpack.unpacker.Unpacker;
 
+import brainwine.gameserver.msgpack.DefaultEnumValue;
 import brainwine.gameserver.msgpack.EnumValue;
 
+@SuppressWarnings("unchecked")
 public class EnumTemplate<T> extends AbstractTemplate<T> {
     
     private final Map<T, Object> ids = new HashMap<>();
     private final Map<Object, T> values = new HashMap<>();
+    private T defaultValue;
     
     public EnumTemplate(Class<T> type) {
         T[] entries = type.getEnumConstants();
         
         for(Field field : type.getFields()) {
+            if(field.getType() == type && field.isAnnotationPresent(DefaultEnumValue.class)) {
+                try {
+                    defaultValue = (T)field.get(type);
+                } catch (IllegalArgumentException | IllegalAccessException e) {
+                    throw new MessageTypeException(e);
+                }
+            }
+            
             if(field.isAnnotationPresent(EnumValue.class)) {
                 try {
                     for(T entry : entries) {
@@ -85,9 +96,9 @@ public class EnumTemplate<T> extends AbstractTemplate<T> {
         ValueType next = unpacker.getNextType();
         
         if(next == ValueType.INTEGER) {
-            return values.get(unpacker.readInt());
+            return values.getOrDefault(unpacker.readInt(), defaultValue);
         } else if(next == ValueType.RAW) {
-            return values.get(unpacker.readString());
+            return values.getOrDefault(unpacker.readString(), defaultValue);
         }
         
         throw new MessageTypeException("Unsupported enum id type");