SPIGOT-6480: Players cannot take books from lecterns that were opened by plugins

By: blablubbabc <lukas@wirsindwir.de>

paper-server/nms-patches/net/minecraft/world/inventory/ContainerLectern.patch

@@ -1,10 +1,11 @@
 --- a/net/minecraft/world/inventory/ContainerLectern.java
 +++ b/net/minecraft/world/inventory/ContainerLectern.java
-@@ -5,16 +5,42 @@
+@@ -5,16 +5,43 @@
  import net.minecraft.world.entity.player.EntityHuman;
  import net.minecraft.world.item.ItemStack;
  
 +// CraftBukkit start
++import net.minecraft.world.level.block.entity.TileEntityLectern.LecternInventory;
 +import net.minecraft.world.entity.player.PlayerInventory;
 +import org.bukkit.Bukkit;
 +import org.bukkit.craftbukkit.inventory.CraftInventoryLectern;
@@ -46,7 +47,7 @@
          super(Containers.LECTERN, i);
          a(iinventory, 1);
          a(icontainerproperties, 1);
-@@ -28,6 +54,7 @@
+@@ -28,6 +55,7 @@
              }
          });
          this.a(icontainerproperties);
@@ -54,7 +55,7 @@
      }
  
      @Override
-@@ -53,6 +80,13 @@
+@@ -53,6 +81,13 @@
                          return false;
                      }
  
@@ -68,10 +69,11 @@
                      ItemStack itemstack = this.inventory.splitWithoutUpdate(0);
  
                      this.inventory.update();
-@@ -75,6 +109,7 @@
+@@ -75,6 +110,8 @@
  
      @Override
      public boolean canUse(EntityHuman entityhuman) {
++        if (inventory instanceof LecternInventory && !((LecternInventory) inventory).getLectern().hasBook()) return false; // CraftBukkit
 +        if (!this.checkReachable) return true; // CraftBukkit
          return this.inventory.a(entityhuman);
      }