From 7389733a0f55c0e19ecc93d387b958bf96c2e183 Mon Sep 17 00:00:00 2001
From: Tayrtahn <tayrtahn@gmail.com>
Date: Thu, 13 Aug 2026 10:18:25 +0000
Subject: [PATCH] Fix `GuidebookDataSystem` late MsgEntity warning (#45298)

Send GuidebookData automatically to new clients.
---
 Content.Client/Guidebook/GuidebookDataSystem.cs |  3 ---
 Content.Server/Guidebook/GuidebookDataSystem.cs | 16 ++++++++++++----
 Content.Shared/Guidebook/Events.cs              | 10 ++--------
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/Content.Client/Guidebook/GuidebookDataSystem.cs b/Content.Client/Guidebook/GuidebookDataSystem.cs
index f47ad6ef1b..eb968d960b 100644
--- a/Content.Client/Guidebook/GuidebookDataSystem.cs
+++ b/Content.Client/Guidebook/GuidebookDataSystem.cs
@@ -17,9 +17,6 @@ public sealed class GuidebookDataSystem : EntitySystem
         base.Initialize();
 
         SubscribeNetworkEvent<UpdateGuidebookDataEvent>(OnServerUpdated);
-
-        // Request data from the server
-        RaiseNetworkEvent(new RequestGuidebookDataEvent());
     }
 
     private void OnServerUpdated(UpdateGuidebookDataEvent args)
diff --git a/Content.Server/Guidebook/GuidebookDataSystem.cs b/Content.Server/Guidebook/GuidebookDataSystem.cs
index cf6761ab7d..a83959edd0 100644
--- a/Content.Server/Guidebook/GuidebookDataSystem.cs
+++ b/Content.Server/Guidebook/GuidebookDataSystem.cs
@@ -1,5 +1,8 @@
 using System.Reflection;
 using Content.Shared.Guidebook;
+using Robust.Server.Player;
+using Robust.Shared.Enums;
+using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Utility;
 
@@ -11,6 +14,8 @@ namespace Content.Server.Guidebook;
 /// </summary>
 public sealed partial class GuidebookDataSystem : EntitySystem
 {
+    [Dependency] private IPlayerManager _player = default!;
+
     private readonly Dictionary<string, List<MemberInfo>> _tagged = [];
     private GuidebookData _cachedData = new();
 
@@ -18,18 +23,21 @@ public sealed partial class GuidebookDataSystem : EntitySystem
     {
         base.Initialize();
 
-        SubscribeNetworkEvent<RequestGuidebookDataEvent>(OnRequestRules);
         SubscribeLocalEvent<PrototypesReloadedEventArgs>(OnPrototypesReloaded);
+        _player.PlayerStatusChanged += OnPlayerStatusChanged;
 
         // Build initial cache
         GatherData(ref _cachedData);
     }
 
-    private void OnRequestRules(RequestGuidebookDataEvent ev, EntitySessionEventArgs args)
+    private void OnPlayerStatusChanged(object? sender, SessionStatusEventArgs e)
     {
-        // Send cached data to requesting client
+        if (e.NewStatus != SessionStatus.Connected)
+            return;
+
+        // Send cached data to newly-connected client.
         var sendEv = new UpdateGuidebookDataEvent(_cachedData);
-        RaiseNetworkEvent(sendEv, args.SenderSession);
+        RaiseNetworkEvent(sendEv, e.Session);
     }
 
     private void OnPrototypesReloaded(PrototypesReloadedEventArgs args)
diff --git a/Content.Shared/Guidebook/Events.cs b/Content.Shared/Guidebook/Events.cs
index e43bf4392c..f42a6df283 100644
--- a/Content.Shared/Guidebook/Events.cs
+++ b/Content.Shared/Guidebook/Events.cs
@@ -3,14 +3,8 @@ using Robust.Shared.Serialization;
 namespace Content.Shared.Guidebook;
 
 /// <summary>
-/// Raised by the client on GuidebookDataSystem Initialize to request a
-/// full set of guidebook data from the server.
-/// </summary>
-[Serializable, NetSerializable]
-public sealed class RequestGuidebookDataEvent : EntityEventArgs { }
-
-/// <summary>
-/// Raised by the server at a specific client in response to <see cref="RequestGuidebookDataEvent"/>.
+/// Sends all extracted prototype data needed by GuidebookDataSystem.
+/// Raised by the server directed at newly-connected clients.
 /// Also raised by the server at ALL clients when prototype data is hot-reloaded.
 /// </summary>
 [Serializable, NetSerializable]