Fixed #919

core/src/io/anuke/mindustry/world/blocks/power/PowerNode.java

@@ -134,7 +134,7 @@ public class PowerNode extends PowerBlock{
         graphs.clear();
         Geometry.circle(tile.x, tile.y, (int)(laserRange + 1), (x, y) -> {
             Tile other = world.ltile(x, y);
-            if(valid.test(other)){
+            if(valid.test(other) && !tempTiles.contains(other)){
                 tempTiles.add(other);
             }
         });
@@ -163,8 +163,6 @@ public class PowerNode extends PowerBlock{
         TileEntity entity = tile.entity();
         other = other.link();
 
-        Tile result = other;
-
         if(linkValid(tile, other)){
             tile.configure(other.pos());
             return false;
@@ -172,7 +170,9 @@ public class PowerNode extends PowerBlock{
 
         if(tile == other){
             if(other.entity.power.links.size == 0){
-                getPotentialLinks(tile, link -> tile.configure(link.pos()));
+                getPotentialLinks(tile, link -> {
+                    tile.configure(link.pos());
+                });
             }else{
                 while(entity.power.links.size > 0){
                     tile.configure(entity.power.links.get(0));