From 4090c177f01cff0e3adff47e97862b2eb03e82d3 Mon Sep 17 00:00:00 2001
From: Alexdoru <57050655+Alexdoru@users.noreply.github.com>
Date: Wed, 12 Jul 2023 16:47:20 +0200
Subject: [PATCH] new: resolve NPE in NetHandlerPlayClient#handleSpawnPlayer
 (#152)

---
 ...lerPlayClient_FixHandleSpawnPlayerNPE.java | 35 +++++++++++++++++++
 src/main/resources/patcher.mixins.json        |  1 +
 versions/1.12.2-1.8.9.txt                     |  1 +
 3 files changed, 37 insertions(+)
 create mode 100644 src/main/java/club/sk1er/patcher/mixins/bugfixes/NetHandlerPlayClient_FixHandleSpawnPlayerNPE.java

diff --git a/src/main/java/club/sk1er/patcher/mixins/bugfixes/NetHandlerPlayClient_FixHandleSpawnPlayerNPE.java b/src/main/java/club/sk1er/patcher/mixins/bugfixes/NetHandlerPlayClient_FixHandleSpawnPlayerNPE.java
new file mode 100644
index 000000000..40119c6ae
--- /dev/null
+++ b/src/main/java/club/sk1er/patcher/mixins/bugfixes/NetHandlerPlayClient_FixHandleSpawnPlayerNPE.java
@@ -0,0 +1,35 @@
+package club.sk1er.patcher.mixins.bugfixes;
+
+import net.minecraft.client.network.NetHandlerPlayClient;
+import net.minecraft.client.network.NetworkPlayerInfo;
+import net.minecraft.network.play.server.S0CPacketSpawnPlayer;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.UUID;
+
+@Mixin(NetHandlerPlayClient.class)
+public abstract class NetHandlerPlayClient_FixHandleSpawnPlayerNPE {
+
+    @Shadow
+    public abstract NetworkPlayerInfo getPlayerInfo(UUID p_175102_1_);
+
+    @Inject(
+        method = "handleSpawnPlayer",
+        cancellable = true,
+        at =
+        @At(
+            value = "INVOKE",
+            target = "Lnet/minecraft/network/PacketThreadUtil;checkThreadAndEnqueue(Lnet/minecraft/network/Packet;Lnet/minecraft/network/INetHandler;Lnet/minecraft/util/IThreadListener;)V",
+            shift = At.Shift.AFTER
+        ))
+    private void patcher$fixHandleSpawnPlayerNPE(S0CPacketSpawnPlayer packetIn, CallbackInfo ci) {
+        if (this.getPlayerInfo(packetIn.getPlayer()) == null) {
+            ci.cancel();
+        }
+    }
+
+}
diff --git a/src/main/resources/patcher.mixins.json b/src/main/resources/patcher.mixins.json
index 454a91bc2..cbf348af7 100644
--- a/src/main/resources/patcher.mixins.json
+++ b/src/main/resources/patcher.mixins.json
@@ -68,6 +68,7 @@
     "bugfixes.MinecraftMixin_FixScreenState",
     "bugfixes.MinecraftMixin_ForeignKeyboards",
     "bugfixes.MinecraftMixin_PersistentShaders",
+    "bugfixes.NetHandlerPlayClient_FixHandleSpawnPlayerNPE",
     "bugfixes.RenderPlayerMixin_ArmPosition",
     "bugfixes.ScoreboardMixin_FixLogSpam",
     "bugfixes.SoundManagerMixin_DuplicatedSounds",
diff --git a/versions/1.12.2-1.8.9.txt b/versions/1.12.2-1.8.9.txt
index 862196177..b47904232 100644
--- a/versions/1.12.2-1.8.9.txt
+++ b/versions/1.12.2-1.8.9.txt
@@ -41,6 +41,7 @@ net.minecraft.network.play.server.SPacketEntityHeadLook net.minecraft.network.pl
 net.minecraft.network.play.server.SPacketEntityStatus net.minecraft.network.play.server.S19PacketEntityStatus
 net.minecraft.network.play.server.SPacketCloseWindow net.minecraft.network.play.server.S2EPacketCloseWindow
 net.minecraft.network.play.server.SPacketCustomPayload net.minecraft.network.play.server.S3FPacketCustomPayload
+net.minecraft.network.play.server.SPacketSpawnPlayer net.minecraft.network.play.server.S0CPacketSpawnPlayer
 net.minecraft.network.status.client.CPacketServerQuery net.minecraft.network.status.client.C00PacketServerQuery
 net.minecraft.network.status.server.SPacketServerInfo net.minecraft.network.status.server.S00PacketServerInfo
 net.minecraft.network.status.server.SPacketPong net.minecraft.network.status.server.S01PacketPong