Send server URL on hasJoined (#6416)

* Send server URL when advertising

* Fix

---------

Co-authored-by: PJB3005 <pieterjan.briers+git@gmail.com>

Robust.Server/ServerHub/HubManager.cs

@@ -52,6 +52,7 @@ internal sealed partial class HubManager
             try
             {
                 url = await GuessAddress();
+                _cfg.SetCVar(CVars.HubServerUrl, url);
             }
             catch (Exception e)
             {
@@ -139,7 +140,7 @@ internal sealed partial class HubManager
         }
     }
 
-    private async Task<string?> GuessAddress()
+    private async Task<string> GuessAddress()
     {
         DebugTools.AssertNotNull(_httpClient);
 

Robust.Shared/Network/NetManager.ServerAuth.cs

@@ -140,7 +140,12 @@ namespace Robust.Shared.Network
                     var authHashBytes = MakeAuthHash(sharedSecret, CryptoPublicKey!);
                     var authHash = Base64Helpers.ConvertToBase64Url(authHashBytes);
 
-                    var url = $"{authServer}api/session/hasJoined?hash={authHash}&userId={msgEncResponse.UserId}";
+                    var url = $"{authServer}api/session/hasJoined" +
+                              $"?hash={authHash}&" +
+                              $"userId={msgEncResponse.UserId}";
+                    var serverUrl = _config.GetCVar(CVars.HubServerUrl);
+                    if (!string.IsNullOrWhiteSpace(serverUrl))
+                        url += $"&serverUrl={Uri.EscapeDataString(serverUrl)}";
                     var joinedRespJson = await _http.Client.GetFromJsonAsync<HasJoinedResponse>(url);
 
                     if (joinedRespJson is not {IsValid: true})