Update lectern if updated via the WindowItemsPacket

connector/src/main/java/org/geysermc/connector/network/translators/inventory/translators/LecternInventoryTranslator.java

@@ -78,12 +78,24 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
 
     @Override
     public void updateInventory(GeyserSession session, Inventory inventory) {
+        GeyserItemStack itemStack = inventory.getItem(0);
+        if (!itemStack.isEmpty()) {
+            updateBook(session, inventory, itemStack);
+        }
     }
 
     @Override
     public void updateSlot(GeyserSession session, Inventory inventory, int slot) {
         this.updater.updateSlot(this, session, inventory, slot);
         if (slot == 0) {
+            updateBook(session, inventory, inventory.getItem(0));
+        }
+    }
+
+    /**
+     * Translate the data of the book in the lectern into a block entity tag.
+     */
+    private void updateBook(GeyserSession session, Inventory inventory, GeyserItemStack book) {
         LecternContainer lecternContainer = (LecternContainer) inventory;
         if (session.isDroppingLecternBook()) {
             // We have to enter the inventory GUI to eject the book
@@ -92,18 +104,17 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
             session.setDroppingLecternBook(false);
             InventoryUtils.closeInventory(session, inventory.getId(), false);
         } else if (lecternContainer.getBlockEntityTag() == null) {
-                // If the method returns true, this is already handled for us
+            CompoundTag tag = book.getNbt();
-                GeyserItemStack geyserItemStack = inventory.getItem(0);
-                CompoundTag tag = geyserItemStack.getNbt();
             // Position has to be the last interacted position... right?
             Vector3i position = session.getLastInteractionBlockPosition();
+            // If shouldExpectLecternHandled returns true, this is already handled for us
             // shouldRefresh means that we should boot out the client on our side because their lectern GUI isn't updated yet
             boolean shouldRefresh = !session.getConnector().getWorldManager().shouldExpectLecternHandled() && !session.getLecternCache().contains(position);
 
             NbtMap blockEntityTag;
             if (tag != null) {
                 int pagesSize = ((ListTag) tag.get("pages")).size();
-                    ItemData itemData = geyserItemStack.getItemData(session);
+                ItemData itemData = book.getItemData(session);
                 NbtMapBuilder lecternTag = getBaseLecternTag(position.getX(), position.getY(), position.getZ(), pagesSize);
                 lecternTag.putCompound("book", NbtMap.builder()
                         .putByte("Count", (byte) itemData.getCount())
@@ -145,7 +156,6 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
             }
         }
     }
-    }
 
     @Override
     public Inventory createInventory(String name, int windowId, WindowType windowType, PlayerInventory playerInventory) {