Cleanup

core/src/mindustry/editor/EditorTile.java

@@ -93,7 +93,7 @@ public class EditorTile extends Tile{
         }
 
         if(!floor.hasSurface() && overlay.asFloor().needsSurface && (overlay instanceof OreBlock || !floor.supportsOverlay)) return;
-        if(overlay() == overlay) return;
+        if(this.overlay == overlay) return;
         op(DrawOperation.opOverlay, this.overlay.id);
         super.setOverlay(overlay);
     }

core/src/mindustry/editor/MapEditorDialog.java

@@ -748,7 +748,11 @@ public class MapEditorDialog extends Dialog implements Disposable{
         //ctrl keys (undo, redo, save)
         if(Core.input.ctrl()){
             if(Core.input.keyTap(KeyCode.z)){
-                editor.undo();
+                if(Core.input.shift()){
+                    editor.redo();
+                }else{
+                    editor.undo();
+                }
             }
 
             if(Core.input.keyTap(KeyCode.y)){