Fixed #11072

core/src/mindustry/editor/DrawOperation.java

@@ -25,6 +25,14 @@ public class DrawOperation{
         return array.isEmpty();
     }
 
+    public int size(){
+        return array.size;
+    }
+
+    public void remove(int amount){
+        array.setSize(Math.max(0, array.size - amount));
+    }
+
     public void addOperation(long op){
         array.add(op);
     }

core/src/mindustry/editor/MapEditor.java

@@ -157,11 +157,19 @@ public class MapEditor{
                 if(!tester.get(tile)) return;
                 boolean changed = false;
 
+                boolean didDataOp = false;
+                int oldData1 = 0, oldData2 = 0;
+
                 if(drawBlock.saveData || tile.shouldSaveData()){
                     addTileOp(TileOp.get(tile.x, tile.y, DrawOperation.opData, TileOpData.get(tile.data, tile.floorData, tile.overlayData)));
                     addTileOp(TileOp.get(tile.x, tile.y, DrawOperation.opDataExtra, tile.extraData));
+                    oldData1 = TileOpData.get(tile.data, tile.floorData, tile.overlayData);
+                    oldData2 = tile.extraData;
+                    didDataOp = true;
                 }
 
+                int preDataOps = ops();
+
                 if(isFloor){
                     if(forceOverlay){
                         tile.setOverlay(drawBlock.asFloor());
@@ -189,6 +197,11 @@ public class MapEditor{
                     drawBlock.placeEnded(tile, null, editor.rotation, drawBlock.lastConfig);
                     renderer.updateStatic(tile.x, tile.y);
                 }
+
+                //data and block did not change, undo the data ops
+                if(didDataOp && ops() == preDataOps && oldData1 == TileOpData.get(tile.data, tile.floorData, tile.overlayData) && oldData2 == tile.extraData){
+                    removeLastOps(2);
+                }
             };
 
             if(square){
@@ -397,6 +410,17 @@ public class MapEditor{
         renderer.updateStatic(TileOp.x(data), TileOp.y(data));
     }
 
+    public int ops(){
+        if(currentOp == null) return 0;
+        return currentOp.size();
+    }
+
+    public void removeLastOps(int amount){
+        if(currentOp == null || loading) return;
+
+        currentOp.remove(amount);
+    }
+
     class Context implements WorldContext{
         @Override
         public Tile tile(int index){