Add a check for construction ghosts beeing present to ConstructionSystem/SpawnGhost (#1642)

Content.Client/GameObjects/EntitySystems/ConstructionSystem.cs

@@ -153,6 +153,11 @@ namespace Content.Client.GameObjects.EntitySystems
         /// </summary>
         public void SpawnGhost(ConstructionPrototype prototype, GridCoordinates loc, Direction dir)
         {
+            if (GhostPresent(loc))
+            {
+                return;
+            }
+
             var ghost = _entityManager.SpawnEntity("constructionghost", loc);
             var comp = ghost.GetComponent<ConstructionGhostComponent>();
             comp.Prototype = prototype;
@@ -167,6 +172,22 @@ namespace Content.Client.GameObjects.EntitySystems
             sprite.LayerSetVisible(0, true);
         }
 
+        /// <summary>
+        /// Checks if any construction ghosts are present at the given position
+        /// </summary>
+        private bool GhostPresent(GridCoordinates loc)
+        {
+            foreach (KeyValuePair<int, ConstructionGhostComponent> ghost in _ghosts)
+            {
+                if (ghost.Value.Owner.Transform.GridPosition.Equals(loc))
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
         private void TryStartConstruction(int ghostId)
         {
             var ghost = _ghosts[ghostId];