Fix issue introduced in c815d4b

Author: raoulvdberge

src/main/java/com/raoulvdberge/refinedstorage/tile/grid/portable/TilePortableGrid.java

@@ -108,7 +108,7 @@ public class TilePortableGrid extends TileBase implements IGrid, IPortableGrid,
     private static final String NBT_STORAGE_TRACKER = "StorageTracker";
     private static final String NBT_FLUID_STORAGE_TRACKER = "FluidStorageTracker";
     private static final String NBT_TYPE = "Type";
-    private static final String NBT_ENCHANTMENTS = "ench";
+    private static final String NBT_ENCHANTMENTS = "ench"; // @Volatile: minecraft specific nbt key
     private EnergyStorage energyStorage = recreateEnergyStorage(0);
     private PortableGridType type;
 
@@ -247,10 +247,10 @@ public void onPassItemContext(ItemStack stack) {
             if (stack.getTagCompound().hasKey(PortableGrid.NBT_FLUID_STORAGE_TRACKER)) {
                 fluidStorageTracker.readFromNbt(stack.getTagCompound().getTagList(PortableGrid.NBT_FLUID_STORAGE_TRACKER, Constants.NBT.TAG_COMPOUND));
             }
+
             if (stack.getTagCompound().hasKey(NBT_ENCHANTMENTS)) {
                 enchants = stack.getTagCompound().getTagList(NBT_ENCHANTMENTS, Constants.NBT.TAG_COMPOUND);
             }
-
         }
 
         this.diskState = getDiskState(this);
@@ -276,11 +276,11 @@ public ItemStack getAsItem() {
 
         stack.getTagCompound().setTag(PortableGrid.NBT_STORAGE_TRACKER, storageTracker.serializeNbt());
         stack.getTagCompound().setTag(PortableGrid.NBT_FLUID_STORAGE_TRACKER, fluidStorageTracker.serializeNbt());
+
         if (enchants != null) {
             stack.getTagCompound().setTag(NBT_ENCHANTMENTS, enchants);
         }
 
-
         stack.getCapability(CapabilityEnergy.ENERGY, null).receiveEnergy(energyStorage.getEnergyStored(), false);
 
         for (int i = 0; i < 4; ++i) {
@@ -611,7 +611,10 @@ public NBTTagCompound write(NBTTagCompound tag) {
 
         tag.setTag(NBT_STORAGE_TRACKER, storageTracker.serializeNbt());
         tag.setTag(NBT_FLUID_STORAGE_TRACKER, fluidStorageTracker.serializeNbt());
-        tag.setTag(NBT_ENCHANTMENTS, enchants);
+
+        if (enchants != null) {
+            tag.setTag(NBT_ENCHANTMENTS, enchants);
+        }
 
         return tag;
     }
@@ -660,10 +663,10 @@ public void read(NBTTagCompound tag) {
         if (tag.hasKey(NBT_FLUID_STORAGE_TRACKER)) {
             fluidStorageTracker.readFromNbt(tag.getTagList(NBT_FLUID_STORAGE_TRACKER, Constants.NBT.TAG_COMPOUND));
         }
+
         if (tag.hasKey(NBT_ENCHANTMENTS)) {
             enchants = tag.getTagList(NBT_ENCHANTMENTS, Constants.NBT.TAG_COMPOUND);
         }
-
     }
 
     @Override