Handle no-NBT lecterns

bootstrap/spigot/src/main/java/org/geysermc/platform/spigot/world/manager/GeyserSpigotWorldManager.java

@@ -203,19 +203,29 @@ public class GeyserSpigotWorldManager extends GeyserWorldManager {
                 return;
             }
             BookMeta bookMeta = (BookMeta) itemStack.getItemMeta();
-            NbtMapBuilder lecternTag = LecternInventoryTranslator.getBaseLecternTag(x, y, z, bookMeta.getPageCount());
+            // On the count: allow the book to show/open even there are no pages. We know there is a book here, after all, and this matches Java behavior
+            boolean hasBookPages = bookMeta.getPageCount() > 0;
+            NbtMapBuilder lecternTag = LecternInventoryTranslator.getBaseLecternTag(x, y, z, hasBookPages ? bookMeta.getPageCount() : 1);
             lecternTag.putInt("page", lectern.getPage() / 2);
             NbtMapBuilder bookTag = NbtMap.builder()
                     .putByte("Count", (byte) itemStack.getAmount())
                     .putShort("Damage", (short) 0)
                     .putString("Name", "minecraft:writable_book");
-            List<NbtMap> pages = new ArrayList<>();
+            List<NbtMap> pages = new ArrayList<>(bookMeta.getPageCount());
+            if (hasBookPages) {
                 for (String page : bookMeta.getPages()) {
                     NbtMapBuilder pageBuilder = NbtMap.builder()
                             .putString("photoname", "")
                             .putString("text", page);
                     pages.add(pageBuilder.build());
                 }
+            } else {
+                // Empty page
+                NbtMapBuilder pageBuilder = NbtMap.builder()
+                        .putString("photoname", "")
+                        .putString("text", "");
+                pages.add(pageBuilder.build());
+            }
             bookTag.putCompound("tag", NbtMap.builder().putList("pages", NbtType.COMPOUND, pages).build());
             lecternTag.putCompound("book", bookTag.build());
             NbtMap blockEntityTag = lecternTag.build();

connector/src/main/java/org/geysermc/connector/network/session/GeyserSession.java

@@ -175,7 +175,7 @@ public class GeyserSession implements CommandSender {
      * See {@link org.geysermc.connector.network.translators.world.WorldManager#getLecternDataAt(GeyserSession, int, int, int, boolean)}
      * for more information.
      */
-    private final List<Vector3i> lecternCache = new ArrayList<>();
+    private final Set<Vector3i> lecternCache = new ObjectOpenHashSet<>();
 
     @Setter
     private boolean droppingLecternBook;

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

@@ -33,6 +33,7 @@ import com.github.steveice10.opennbt.tag.builtin.ListTag;
 import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NbtMap;
 import com.nukkitx.nbt.NbtMapBuilder;
+import com.nukkitx.nbt.NbtType;
 import com.nukkitx.protocol.bedrock.data.inventory.ItemData;
 import org.geysermc.connector.inventory.GeyserItemStack;
 import org.geysermc.connector.inventory.Inventory;
@@ -43,6 +44,8 @@ import org.geysermc.connector.network.translators.inventory.updater.InventoryUpd
 import org.geysermc.connector.utils.BlockEntityUtils;
 import org.geysermc.connector.utils.InventoryUtils;
 
+import java.util.Collections;
+
 public class LecternInventoryTranslator extends BaseInventoryTranslator {
     private final InventoryUpdater updater;
 
@@ -96,11 +99,12 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
                 // If the method returns true, this is already handled for us
                 GeyserItemStack geyserItemStack = inventory.getItem(0);
                 CompoundTag tag = geyserItemStack.getNbt();
-                if (tag != null) {
                 // Position has to be the last interacted position... right?
                 Vector3i position = session.getLastInteractionBlockPosition();
                 // 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);
                     NbtMapBuilder lecternTag = getBaseLecternTag(position.getX(), position.getY(), position.getZ(), pagesSize);
@@ -111,7 +115,23 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
                             .putCompound("tag", itemData.getTag())
                             .build());
                     lecternTag.putInt("page", lecternContainer.getCurrentBedrockPage());
-                    NbtMap blockEntityTag = lecternTag.build();
+                    blockEntityTag = lecternTag.build();
+                } else {
+                    // There is *a* book here, but... no NBT.
+                    NbtMapBuilder lecternTag = getBaseLecternTag(position.getX(), position.getY(), position.getZ(), 1);
+                    NbtMapBuilder bookTag = NbtMap.builder()
+                            .putByte("Count", (byte) 1)
+                            .putShort("Damage", (short) 0)
+                            .putString("Name", "minecraft:writable_book")
+                            .putCompound("tag", NbtMap.builder().putList("pages", NbtType.COMPOUND, Collections.singletonList(
+                                    NbtMap.builder()
+                                        .putString("photoname", "")
+                                        .putString("text", "")
+                                    .build()
+                            )).build());
+
+                    blockEntityTag = lecternTag.putCompound("book", bookTag.build()).build();
+                }
                 // Even with serverside access to lecterns, we don't easily know which lectern this is, so we need to rebuild
                 // the block entity tag
                 lecternContainer.setBlockEntityTag(blockEntityTag);
@@ -128,7 +148,6 @@ public class LecternInventoryTranslator extends BaseInventoryTranslator {
             }
         }
     }
-    }
 
     @Override
     public Inventory createInventory(String name, int windowId, WindowType windowType, PlayerInventory playerInventory) {

connector/src/main/java/org/geysermc/connector/utils/ChunkUtils.java

@@ -401,7 +401,6 @@ public class ChunkUtils {
             boolean newLecternHasBook = BlockStateValues.getLecternBookStates().get(blockState);
             if (!session.getConnector().getWorldManager().shouldExpectLecternHandled() && lecternCachedHasBook != newLecternHasBook) {
                 // Refresh the block entirely - it either has a book or no longer has a book
-                session.getConnector().getLogger().warning("Refreshing lectern entirely");
                 NbtMap newLecternTag;
                 if (newLecternHasBook) {
                     newLecternTag = session.getConnector().getWorldManager().getLecternDataAt(session, position.getX(), position.getY(), position.getZ(), false);