Fix ghost blocks

worldedit-bukkit/src/main/java/com/boydti/fawe/bukkit/v1_13/BukkitQueue_1_13.java

@@ -684,6 +684,12 @@ public class BukkitQueue_1_13 extends BukkitQueue_0<net.minecraft.server.v1_13_R
             return false;
         }
         if (playerChunk.e()) {
+            ChunkSection[] sections = nmsChunk.getSections();
+            for (int layer = 0; layer < 16; layer++) {
+                if (sections[layer] == null && (mask & (1 << layer)) != 0) {
+                    sections[layer] = new ChunkSection(layer << 4, nmsWorld.worldProvider.g());
+                }
+            }
             TaskManager.IMP.sync(new Supplier<Object>() {
                 @Override
                 public Object get() {

worldedit-core/src/main/java/com/boydti/fawe/object/changeset/FaweChangeSet.java

@@ -15,6 +15,7 @@ import com.boydti.fawe.util.TaskManager;
 import com.sk89q.jnbt.CompoundTag;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.world.block.BaseBlock;
+import com.sk89q.worldedit.world.block.BlockID;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.extent.inventory.BlockBag;
 import com.sk89q.worldedit.history.change.BlockChange;
@@ -281,7 +282,6 @@ public abstract class FaweChangeSet implements ChangeSet {
                                             index++;
                                         }
                                     }
-                                    // TODO
                                 }
                                 // Block changes
                                 for (int layer = 0; layer < layers; layer++) {
@@ -305,7 +305,7 @@ public abstract class FaweChangeSet implements ChangeSet {
                                                     case 1:
                                                         combinedIdCurrent = 0;
                                                     default:
-                                                        int combinedIdPrevious = previousLayer != null ? previousLayer[index] : 0;
+                                                        int combinedIdPrevious = previousLayer != null ? previousLayer[index] : BlockID.AIR;
                                                         if (combinedIdCurrent != combinedIdPrevious) {
                                                             add(xx, yy, zz, combinedIdPrevious, combinedIdCurrent);
                                                         }