fix/fabric: fix first item slot not syncing

fabric/src/main/java/net/william278/husksync/data/FabricData.java

@@ -163,9 +163,7 @@ public abstract class FabricData implements Data {
                 player.currentScreenHandler.setCursorStack(ItemStack.EMPTY);
                 final ItemStack[] items = getContents();
                 for (int slot = 0; slot < player.getInventory().size(); slot++) {
-                    player.getInventory().setStack(
-                            slot, items[slot] == null ? ItemStack.EMPTY : items[slot]
-                    );
+                    player.getInventory().setStack(slot, items[slot] == null ? ItemStack.EMPTY : items[slot]);
                 }
                 player.getInventory().selectedSlot = heldItemSlot;
                 player.playerScreenHandler.sendContentUpdates();

fabric/src/main/java/net/william278/husksync/data/FabricSerializer.java

@@ -150,6 +150,7 @@ public abstract class FabricSerializer {
         int VERSION1_20_2 = 3578; // Future
         int VERSION1_20_4 = 3700; // Future
         int VERSION1_20_5 = 3837; // Future
+        int VERSION1_21 = 3953; // Future
 
         @NotNull
         default ItemStack[] getItems(@NotNull NbtCompound tag, @NotNull Version mcVersion, @NotNull FabricHuskSync plugin) {
@@ -158,15 +159,14 @@ public abstract class FabricSerializer {
                     return upgradeItemStacks(tag, mcVersion, plugin);
                 }
 
-                final int size = tag.getInt("size");
-                final NbtList items = tag.getList("items", NbtElement.COMPOUND_TYPE);
-                final ItemStack[] itemStacks = new ItemStack[size];
-                for (int i = 0; i < size; i++) {
-                    final NbtCompound compound = items.getCompound(i);
-                    final int slot = compound.getInt("Slot");
-                    itemStacks[slot] = ItemStack.fromNbt(compound);
-                }
-                return itemStacks;
+                final ItemStack[] contents = new ItemStack[tag.getInt("size")];
+                final NbtList itemList = tag.getList("items", NbtElement.COMPOUND_TYPE);
+                itemList.forEach(element -> {
+                    final NbtCompound compound = (NbtCompound) element;
+                    contents[compound.getInt("Slot")] = ItemStack.fromNbt(compound);
+                });
+                plugin.debug(Arrays.toString(contents));
+                return contents;
             } catch (Throwable e) {
                 throw new Serializer.DeserializationException("Failed to read item NBT string (%s)".formatted(tag), e);
             }
@@ -232,6 +232,7 @@ public abstract class FabricSerializer {
                 case "1.20.2" -> VERSION1_20_2; // Future
                 case "1.20.4" -> VERSION1_20_4; // Future
                 case "1.20.5", "1.20.6" -> VERSION1_20_5; // Future
+                case "1.21" -> VERSION1_21; // Future
                 default -> VERSION1_20_1; // Current supported ver
             };
         }