From 845fcefad7b899532cb33a8e4b8e75c49ee9ff12 Mon Sep 17 00:00:00 2001
From: Evil Factory <36804725+evilfactory@users.noreply.github.com>
Date: Sun, 1 Mar 2026 09:50:52 -0300
Subject: [PATCH] Fix Start(0 not returning an empty write only message

---
 .../LuaCs/Compatibility/ILuaCsNetworking.cs          |  1 +
 .../LuaCs/_Services/NetworkingService.cs             | 12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Barotrauma/BarotraumaShared/SharedSource/LuaCs/Compatibility/ILuaCsNetworking.cs b/Barotrauma/BarotraumaShared/SharedSource/LuaCs/Compatibility/ILuaCsNetworking.cs
index 0f2388df9..4aae5b61e 100644
--- a/Barotrauma/BarotraumaShared/SharedSource/LuaCs/Compatibility/ILuaCsNetworking.cs
+++ b/Barotrauma/BarotraumaShared/SharedSource/LuaCs/Compatibility/ILuaCsNetworking.cs
@@ -15,6 +15,7 @@ internal interface ILuaCsNetworking : ILuaCsShim
     int FileSenderMaxPacketsPerUpdate { get; set; }
     void ClientWriteLobby(Client client);
     void UpdateClientPermissions(Client client);
+    IWriteMessage Start();
     void Send(IWriteMessage mesage, NetworkConnection connection = null, DeliveryMethod deliveryMethod = DeliveryMethod.Reliable);
 #elif CLIENT
     void Send(IWriteMessage mesage, DeliveryMethod deliveryMethod = DeliveryMethod.Reliable);
diff --git a/Barotrauma/BarotraumaShared/SharedSource/LuaCs/_Services/NetworkingService.cs b/Barotrauma/BarotraumaShared/SharedSource/LuaCs/_Services/NetworkingService.cs
index 622f7395f..8482bebc3 100644
--- a/Barotrauma/BarotraumaShared/SharedSource/LuaCs/_Services/NetworkingService.cs
+++ b/Barotrauma/BarotraumaShared/SharedSource/LuaCs/_Services/NetworkingService.cs
@@ -127,8 +127,18 @@ internal partial class NetworkingService : INetworkingService
 
     public void Receive(string netIdString, NetMessageReceived callback) => Receive(new NetId(netIdString), callback);
     public void Receive(Guid netIdGuid, NetMessageReceived callback) => Receive(new NetId(netIdGuid.ToString()), callback);
-    public IWriteMessage Start(string netIdString) => Start(new NetId(netIdString));
+    public IWriteMessage Start(string netIdString)
+    {
+        if (netIdString == null)
+        {
+            // idk why but Lua calls this method with null instead of the Start method with no arguments
+            return new WriteOnlyMessage();
+        }
+
+        return Start(new NetId(netIdString));
+    }
     public IWriteMessage Start(Guid netIdGuid) => Start(new NetId(netIdGuid.ToString()));
+    public IWriteMessage Start() => new WriteOnlyMessage();
 
     internal void Receive(NetId netId, NetMessageReceived callback)
     {