From 6af4a4d9b8494228dbcc9e5e6037fb7dbe6f9649 Mon Sep 17 00:00:00 2001
From: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>
Date: Mon, 14 Apr 2025 02:09:56 +1000
Subject: [PATCH] Fix user interface interaction validation (#36480)

---
 .../Interaction/SharedInteractionSystem.cs      | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/Content.Shared/Interaction/SharedInteractionSystem.cs b/Content.Shared/Interaction/SharedInteractionSystem.cs
index 9a2706d8a0..00246bafcd 100644
--- a/Content.Shared/Interaction/SharedInteractionSystem.cs
+++ b/Content.Shared/Interaction/SharedInteractionSystem.cs
@@ -106,7 +106,9 @@ namespace Content.Shared.Interaction
             _uiQuery = GetEntityQuery<ActivatableUIComponent>();
 
             SubscribeLocalEvent<BoundUserInterfaceCheckRangeEvent>(HandleUserInterfaceRangeCheck);
-            SubscribeLocalEvent<ActivatableUIComponent, BoundUserInterfaceMessageAttempt>(OnBoundInterfaceInteractAttempt);
+
+            // TODO make this a broadcast event subscription again when engine has updated.
+            SubscribeLocalEvent<UserInterfaceComponent, BoundUserInterfaceMessageAttempt>(OnBoundInterfaceInteractAttempt);
 
             SubscribeAllEvent<InteractInventorySlotEvent>(HandleInteractInventorySlotEvent);
 
@@ -151,12 +153,15 @@ namespace Content.Shared.Interaction
         /// <summary>
         ///     Check that the user that is interacting with the BUI is capable of interacting and can access the entity.
         /// </summary>
-        private void OnBoundInterfaceInteractAttempt(Entity<ActivatableUIComponent> ent, ref BoundUserInterfaceMessageAttempt ev)
+        private void OnBoundInterfaceInteractAttempt(Entity<UserInterfaceComponent> ent, ref BoundUserInterfaceMessageAttempt ev)
         {
+            _uiQuery.TryComp(ev.Target, out var aUiComp);
             if (!_actionBlockerSystem.CanInteract(ev.Actor, ev.Target))
             {
                 // We permit ghosts to open uis unless explicitly blocked
-                if (ev.Message is not OpenBoundInterfaceMessage || !HasComp<GhostComponent>(ev.Actor) || ent.Comp.BlockSpectators)
+                if (ev.Message is not OpenBoundInterfaceMessage
+                    || !HasComp<GhostComponent>(ev.Actor)
+                    || aUiComp?.BlockSpectators == true)
                 {
                     ev.Cancel();
                     return;
@@ -174,14 +179,16 @@ namespace Content.Shared.Interaction
                 return;
             }
 
+            if (aUiComp == null)
+                return;
 
-            if (ent.Comp.SingleUser && ent.Comp.CurrentSingleUser != null && ent.Comp.CurrentSingleUser != ev.Actor)
+            if (aUiComp.SingleUser && aUiComp.CurrentSingleUser != null && aUiComp.CurrentSingleUser != ev.Actor)
             {
                 ev.Cancel();
                 return;
             }
 
-            if (ent.Comp.RequiresComplex && !_actionBlockerSystem.CanComplexInteract(ev.Actor))
+            if (aUiComp.RequiresComplex && !_actionBlockerSystem.CanComplexInteract(ev.Actor))
                 ev.Cancel();
         }
 
-- 
2.51.2