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)){

core/src/mindustry/world/Tile.java

@@ -308,7 +308,7 @@ public class Tile implements Position, QuadTreeObject, Displayable{
             pathfinder.updateTile(this);
         }
 
-        if(!world.isGenerating() && prev != type){
+        if(!world.isGenerating()){
             Events.fire(floorChange.set(this, prev, type));
         }
 
@@ -404,6 +404,8 @@ public class Tile implements Position, QuadTreeObject, Displayable{
     }
 
     public void setOverlay(Block block){
+        if(this.overlay == block) return;
+
         this.overlay = (Floor)block;
 
         recache();