Fix Fultons losing their beacon when split (#20179)

Content.Server/Stack/StackSystem.cs

@@ -70,6 +70,9 @@ namespace Content.Server.Stack
                 stackComp.Unlimited = false;
             }
 
+            var ev = new StackSplitEvent(entity);
+            RaiseLocalEvent(uid, ref ev);
+
             return entity;
         }
 

Content.Shared/Salvage/Fulton/FultonComponent.cs

@@ -19,7 +19,7 @@ public sealed partial class FultonComponent : Component
     /// <summary>
     /// Linked fulton beacon.
     /// </summary>
-    [ViewVariables(VVAccess.ReadWrite), DataField("beacon")]
+    [ViewVariables(VVAccess.ReadWrite), DataField("beacon"), AutoNetworkedField]
     public EntityUid? Beacon;
 
     /// <summary>

Content.Shared/Salvage/Fulton/SharedFultonSystem.cs

@@ -43,6 +43,8 @@ public abstract partial class SharedFultonSystem : EntitySystem
         SubscribeLocalEvent<FultonedComponent, EntGotInsertedIntoContainerMessage>(OnFultonContainerInserted);
 
         SubscribeLocalEvent<FultonComponent, AfterInteractEvent>(OnFultonInteract);
+
+        SubscribeLocalEvent<FultonComponent, StackSplitEvent>(OnFultonSplit);
     }
 
     private void OnFultonContainerInserted(EntityUid uid, FultonedComponent component, EntGotInsertedIntoContainerMessage args)
@@ -161,6 +163,13 @@ public abstract partial class SharedFultonSystem : EntitySystem
             });
     }
 
+    private void OnFultonSplit(EntityUid uid, FultonComponent component, ref StackSplitEvent args)
+    {
+        var newFulton = EnsureComp<FultonComponent>(args.NewId);
+        newFulton.Beacon = component.Beacon;
+        Dirty(args.NewId, newFulton);
+    }
+
     protected virtual void UpdateAppearance(EntityUid uid, FultonedComponent fultoned)
     {
         return;

Content.Shared/Stacks/StackSplitEvent.cs

@@ -0,0 +1,8 @@
+namespace Content.Shared.Stacks;
+
+/// <summary>
+///     Raised on the original stack entity when it is split to create another.
+/// </summary>
+/// <param name="NewId">The entity id of the new stack.</param>
+[ByRefEvent]
+public readonly record struct StackSplitEvent(EntityUid NewId);