Fixed #7292

core/src/mindustry/entities/comp/BuildingComp.java

@@ -152,6 +152,13 @@ abstract class BuildingComp implements Posc, Teamc, Healthc, Buildingc, Timerc,
         return self();
     }
 
+    @Override
+    public void add(){
+        if(power != null){
+            power.graph.checkAdd();
+        }
+    }
+
     @Override
     @Replace
     public int tileX(){

core/src/mindustry/entities/comp/PayloadComp.java

@@ -38,7 +38,7 @@ abstract class PayloadComp implements Posc, Rotc, Hitboxc, Unitc{
         //update power graph first, resolve everything
         for(Payload pay : payloads){
             if(pay instanceof BuildPayload pb && pb.build.power != null){
-                if(payloadPower == null) payloadPower = new PowerGraph();
+                if(payloadPower == null) payloadPower = new PowerGraph(false);
 
                 //pb.build.team = team;
                 pb.build.power.graph = null;

core/src/mindustry/world/blocks/power/PowerGraph.java

@@ -18,7 +18,7 @@ public class PowerGraph{
     public final Seq<Building> batteries = new Seq<>(false, 16, Building.class);
     public final Seq<Building> all = new Seq<>(false, 16, Building.class);
 
-    private final PowerGraphUpdater entity;
+    private final @Nullable PowerGraphUpdater entity;
     private final WindowedMean powerBalance = new WindowedMean(60);
     private float lastPowerProduced, lastPowerNeeded, lastPowerStored;
     private float lastScaledPowerIn, lastScaledPowerOut, lastCapacity;
@@ -34,6 +34,11 @@ public class PowerGraph{
         graphID = lastGraphID++;
     }
 
+    public PowerGraph(boolean noEntity){
+        entity = null;
+        graphID = lastGraphID++;
+    }
+
     public int getID(){
         return graphID;
     }
@@ -251,11 +256,12 @@ public class PowerGraph{
     public void addGraph(PowerGraph graph){
         if(graph == this) return;
         //other entity should be removed as the graph was merged
-        graph.entity.remove();
+        if(graph.entity != null) graph.entity.remove();
 
         for(Building tile : graph.all){
             add(tile);
         }
+        checkAdd();
     }
 
     public void add(Building build){
@@ -264,14 +270,12 @@ public class PowerGraph{
         if(build.power.graph != this || !build.power.init){
             //any old graph that is added here MUST be invalid, remove it
             if(build.power.graph != null && build.power.graph != this){
-                build.power.graph.entity.remove();
+                if( build.power.graph.entity != null) build.power.graph.entity.remove();
             }
 
             build.power.graph = this;
             build.power.init = true;
             all.add(build);
-            //there's something to update, add the entity
-            entity.add();
 
             if(build.block.outputsPower && build.block.consumesPower && !build.block.consPower.buffered){
                 producers.add(build);
@@ -286,13 +290,17 @@ public class PowerGraph{
         }
     }
 
+    public void checkAdd(){
+        if(entity != null) entity.add();
+    }
+
     public void clear(){
         all.clear();
         producers.clear();
         consumers.clear();
         batteries.clear();
         //nothing left
-        entity.remove();
+        if(entity != null) entity.remove();
     }
 
     public void reflow(Building tile){
@@ -302,6 +310,7 @@ public class PowerGraph{
         while(queue.size > 0){
             Building child = queue.removeFirst();
             add(child);
+            checkAdd();
             for(Building next : child.getPowerConnections(outArray2)){
                 if(closedSet.add(next.pos())){
                     queue.addLast(next);
@@ -329,6 +338,7 @@ public class PowerGraph{
 
             //create graph for this branch
             PowerGraph graph = new PowerGraph();
+            graph.checkAdd();
             graph.add(other);
             //add to queue for BFS
             queue.clear();
@@ -353,7 +363,7 @@ public class PowerGraph{
         }
 
         //implied empty graph here
-        entity.remove();
+        if(entity != null) entity.remove();
     }
 
     @Deprecated