Hulls, gaps, structures & waypoints implement ShallowRemove (= a method that's used to remove entities without severing links between them when copypasting).

Copied waypoints used to stay in the waypoint list, causing an exception to be thrown in PathFinder.GenerateNodes due to duplicate IDs.

Subsurface/Source/Map/Hull.cs

@@ -332,6 +332,39 @@ namespace Barotrauma
             Pressure = surface;
         }
 
+        public override void ShallowRemove()
+        {
+            base.Remove();
+            hullList.Remove(this);
+
+            if (Submarine == null || (!Submarine.Loading && !Submarine.Unloading))
+            {
+                Item.UpdateHulls();
+                Gap.UpdateHulls();
+            }
+
+            List<FireSource> fireSourcesToRemove = new List<FireSource>(fireSources);
+            foreach (FireSource fireSource in fireSourcesToRemove)
+            {
+                fireSource.Remove();
+            }
+            fireSources.Clear();
+
+            if (soundIndex > -1)
+            {
+                Sounds.SoundManager.Stop(soundIndex);
+                soundIndex = -1;
+            }
+            
+            if (entityGrids != null)
+            {
+                foreach (EntityGrid entityGrid in entityGrids)
+                {
+                    entityGrid.RemoveEntity(this);
+                }
+            }
+        }
+
         public override void Remove()
         {
             base.Remove();
@@ -355,8 +388,7 @@ namespace Barotrauma
                 Sounds.SoundManager.Stop(soundIndex);
                 soundIndex = -1;
             }
-
-            //renderer.Dispose();
+            
             if (entityGrids != null)
             {
                 foreach (EntityGrid entityGrid in entityGrids)