Better DreamConnection.Session disconnect handling (#2503)

Author: wixoaGit

OpenDreamRuntime/DreamConnection.cs

@@ -18,7 +18,6 @@ public sealed class DreamConnection {
     [Dependency] private readonly DreamManager _dreamManager = default!;
     [Dependency] private readonly DreamObjectTree _objectTree = default!;
     [Dependency] private readonly DreamResourceManager _resourceManager = default!;
-    [Dependency] private readonly WalkManager _walkManager = default!;
     [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
     [Dependency] private readonly ISharedPlayerManager _playerManager = default!;
 
@@ -66,10 +65,11 @@ [ViewVariables] public DreamObjectMob? Mob {
     }
 
     [ViewVariables] public DreamObjectMovable? Eye {
-        get => _eye;
+        get;
         set {
-            _eye = value;
-            _playerManager.SetAttachedEntity(Session!, _eye?.Entity);
+            field = value;
+            if (Session != null)
+                _playerManager.SetAttachedEntity(Session, field?.Entity);
         }
     }
 
@@ -82,7 +82,6 @@ [ViewVariables] public DreamObjectMovable? Eye {
     [ViewVariables] private int _nextPromptEvent = 1;
     private readonly Dictionary<string, DreamResource> _permittedBrowseRscFiles = new();
     private DreamObjectMob? _mob;
-    private DreamObjectMovable? _eye;
 
     private readonly ISawmill _sawmill = Logger.GetSawmill("opendream.connection");
 
@@ -119,6 +118,9 @@ public void HandleDisconnection() {
         if (Session == null || Client == null) // Already disconnected?
             return;
 
+        _verbSystem?.RemoveConnectionFromRepeatingVerbs(this);
+        Session = null;
+
         if (_mob != null) {
             // Don't null out the ckey here
             _mob.SpawnProc("Logout");
@@ -129,12 +131,8 @@ public void HandleDisconnection() {
             }
         }
 
-        _verbSystem?.RemoveConnectionFromRepeatingVerbs(this);
-
         Client.Delete();
         Client = null;
-
-        Session = null;
     }
 
     public void UpdateStat() {
@@ -391,7 +389,7 @@ public Task<DreamValue> WinGet(string controlId, string queryValue) {
         return task;
     }
 
-    public Task<DreamValue> Alert(String title, String message, String button1, String button2, String button3) {
+    public Task<DreamValue> Alert(string title, string message, string button1, string button2, string button3) {
         var task = MakePromptTask(out var promptId);
         var msg = new MsgAlert() {
             PromptId = promptId,
@@ -441,7 +439,6 @@ public void HandleBrowseResourceRequest(string filename) {
         } else {
             _sawmill.Error($"Client({Session}) requested a browse_rsc file they had not been permitted to request ({filename}).");
         }
-
     }
 
     public void Browse(string? body, string? options) {

OpenDreamRuntime/Objects/Types/DreamObjectClient.cs

@@ -77,6 +77,8 @@ protected override bool TryGetVar(string varName, out DreamValue value) {
                 value = new(long.Parse(hashStr, System.Globalization.NumberStyles.HexNumber).ToString()); // Converts from hex to decimal. Output is in analogous format to BYOND's.
                 return true;
             case "address":
+                // TODO: Session could be null if this is gotten from /mob/Logout() or /client/Del()
+                // BYOND's behavior there needs tested
                 value = new(Connection.Session!.Channel.RemoteEndPoint.Address.ToString());
                 return true;
             case "inactivity":

OpenDreamRuntime/Rendering/ServerClientImagesSystem.cs

@@ -9,8 +9,7 @@ public sealed class ServerClientImagesSystem : SharedClientImagesSystem {
     [Dependency] private readonly PvsOverrideSystem _pvsOverrideSystem = default!;
 
     public void AddImageObject(DreamConnection connection, DreamObjectImage imageObject) {
-        DreamObject? loc = imageObject.GetAttachedLoc();
-        if(loc == null)
+        if (connection.Session == null || imageObject.GetAttachedLoc() is not { } loc)
             return;
 
         EntityUid locEntity = EntityUid.Invalid;
@@ -25,13 +24,12 @@ public void AddImageObject(DreamConnection connection, DreamObjectImage imageObj
         EntityUid imageObjectEntity = imageObject.Entity;
         NetEntity imageObjectNetEntity = GetNetEntity(imageObjectEntity);
         if (imageObjectEntity != EntityUid.Invalid)
-            _pvsOverrideSystem.AddSessionOverride(imageObjectEntity, connection.Session!);
-        RaiseNetworkEvent(new AddClientImageEvent(ent, turfCoords, imageObjectNetEntity), connection.Session!.Channel);
+            _pvsOverrideSystem.AddSessionOverride(imageObjectEntity, connection.Session);
+        RaiseNetworkEvent(new AddClientImageEvent(ent, turfCoords, imageObjectNetEntity), connection.Session.Channel);
     }
 
     public void RemoveImageObject(DreamConnection connection, DreamObjectImage imageObject) {
-        DreamObject? loc = imageObject.GetAttachedLoc();
-        if (loc == null)
+        if (connection.Session == null || imageObject.GetAttachedLoc() is not { } loc)
             return;
 
         EntityUid locEntity = EntityUid.Invalid;
@@ -45,8 +43,8 @@ public void RemoveImageObject(DreamConnection connection, DreamObjectImage image
         NetEntity ent = GetNetEntity(locEntity);
         EntityUid imageObjectEntity = imageObject.Entity;
         if (imageObjectEntity != EntityUid.Invalid)
-            _pvsOverrideSystem.RemoveSessionOverride(imageObjectEntity, connection.Session!);
+            _pvsOverrideSystem.RemoveSessionOverride(imageObjectEntity, connection.Session);
         NetEntity imageObjectNetEntity = GetNetEntity(imageObject.Entity);
-        RaiseNetworkEvent(new RemoveClientImageEvent(ent, turfCoords, imageObjectNetEntity), connection.Session!.Channel);
+        RaiseNetworkEvent(new RemoveClientImageEvent(ent, turfCoords, imageObjectNetEntity), connection.Session.Channel);
     }
 }

OpenDreamRuntime/Rendering/ServerScreenOverlaySystem.cs

@@ -9,13 +9,19 @@ public sealed class ServerScreenOverlaySystem : SharedScreenOverlaySystem {
     [Dependency] private readonly PvsOverrideSystem _pvsOverride = default!;
 
     public void AddScreenObject(DreamConnection connection, DreamObjectMovable screenObject) {
+        if (connection.Session is null)
+            return;
+
         _pvsOverride.AddForceSend(screenObject.Entity, connection.Session);
 
         NetEntity ent = _entityManager.GetNetEntity(screenObject.Entity);
         RaiseNetworkEvent(new AddScreenObjectEvent(ent), connection.Session.Channel);
     }
 
     public void RemoveScreenObject(DreamConnection connection, DreamObjectMovable screenObject) {
+        if (connection.Session is null)
+            return;
+
         _pvsOverride.RemoveForceSend(screenObject.Entity, connection.Session);
 
         NetEntity ent = _entityManager.GetNetEntity(screenObject.Entity);

OpenDreamRuntime/ServerVerbSystem.cs

@@ -112,6 +112,9 @@ public void RegisterVerb(DreamProc verb) {
     /// </summary>
     /// <param name="client">The client to update</param>
     public void UpdateClientVerbs(DreamObjectClient client) {
+        if (client.Connection.Session == null)
+            return;
+
         var verbs = client.ClientVerbs.Verbs;
         var verbIds = new List<int>(verbs.Count);
 
@@ -121,7 +124,7 @@ public void UpdateClientVerbs(DreamObjectClient client) {
             verbIds.Add(verb.VerbId!.Value);
         }
 
-        RaiseNetworkEvent(new UpdateClientVerbsEvent(verbIds), client.Connection.Session!);
+        RaiseNetworkEvent(new UpdateClientVerbsEvent(verbIds), client.Connection.Session);
     }
 
     private void OnPlayerStatusChanged(object? sender, SessionStatusEventArgs e) {
@@ -178,7 +181,7 @@ private void OnRepeatVerbStop(UnregisterRepeatVerbEvent msg, EntitySessionEventA
 
     private void RunVerb(DreamProc verb, string name, DreamObject? src, DreamConnection usr, params DreamValue[] arguments) {
         using var _ = Profiler.BeginZone("DM Execution", color: (uint)Color.LightPink.ToArgb());
-        
+
         DreamThread.Run($"Execute {name} by {usr.Session!.Name}", async state => {
             await state.Call(verb, src, usr.Mob, arguments);
             return DreamValue.Null;