fix: NPE on unavailable music discs on lower versions (#3475)

* fix: NPE on unavailable music discs

* chore: documentation for InventoryUtil changes

* fix: no need for additional decrement

* chore: address requested changes

* fix: prevent binary mismatch

Co-authored-by: Alex <mc.cache@web.de>

Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitInventoryUtil.java

@@ -42,6 +42,7 @@ import org.bukkit.inventory.InventoryView;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.PlayerInventory;
 import org.bukkit.inventory.meta.ItemMeta;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -50,11 +51,15 @@ import java.util.stream.IntStream;
 @Singleton
 public class BukkitInventoryUtil extends InventoryUtil {
 
-    private static ItemStack getItem(PlotItemStack item) {
+    private static @Nullable ItemStack getItem(PlotItemStack item) {
         if (item == null) {
             return null;
         }
-        ItemStack stack = new ItemStack(BukkitAdapter.adapt(item.getType()), item.getAmount());
+        Material material = BukkitAdapter.adapt(item.getType());
+        if (material == null) {
+            return null;
+        }
+        ItemStack stack = new ItemStack(material, item.getAmount());
         ItemMeta meta = null;
         if (item.getName() != null) {
             meta = stack.getItemMeta();
@@ -104,14 +109,19 @@ public class BukkitInventoryUtil extends InventoryUtil {
     }
 
     @Override
-    public void setItem(PlotInventory inv, int index, PlotItemStack item) {
+    public boolean setItemChecked(PlotInventory inv, int index, PlotItemStack item) {
         BukkitPlayer bp = (BukkitPlayer) inv.getPlayer();
         InventoryView opened = bp.player.getOpenInventory();
-        if (!inv.isOpen()) {
+        ItemStack stack = getItem(item);
-            return;
+        if (stack == null) {
+            return false;
         }
-        opened.setItem(index, getItem(item));
+        if (!inv.isOpen()) {
+            return true;
+        }
+        opened.setItem(index, stack);
         bp.player.updateInventory();
+        return true;
     }
 
     @SuppressWarnings("deprecation") // Paper deprecation

Core/src/main/java/com/plotsquared/core/command/Music.java

@@ -41,6 +41,7 @@ import com.plotsquared.core.plot.flag.implementations.MusicFlag;
 import com.plotsquared.core.util.EventDispatcher;
 import com.plotsquared.core.util.InventoryUtil;
 import com.plotsquared.core.util.Permissions;
+import com.sk89q.worldedit.world.item.ItemType;
 import com.sk89q.worldedit.world.item.ItemTypes;
 import net.kyori.adventure.text.minimessage.Template;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -148,8 +149,14 @@ public class Music extends SubCommand {
         for (final String disc : DISCS) {
             final String name = String.format("<gold>%s</gold>", disc);
             final String[] lore = {TranslatableCaption.of("plotjukebox.click_to_play").getComponent(player)};
-            final PlotItemStack item = new PlotItemStack(disc, 1, name, lore);
+            ItemType type = ItemTypes.get(disc);
-            inv.setItem(index++, item);
+            if (type == null) {
+                continue;
+            }
+            final PlotItemStack item = new PlotItemStack(type, 1, name, lore);
+            if (inv.setItemChecked(index, item)) {
+                index++;
+            }
         }
 
         // Always add the cancel button

Core/src/main/java/com/plotsquared/core/plot/PlotInventory.java

@@ -103,9 +103,32 @@ public class PlotInventory {
         this.open = false;
     }
 
+    /**
+     * Put an item into this inventory
+     *
+     * @param index the index (= slot) where to place the item
+     * @param item the item to place
+     * @see #setItemChecked(int, PlotItemStack)
+     */
     public void setItem(int index, PlotItemStack item) {
+        setItemChecked(index, item);
+    }
+
+    /**
+     * Put an item into this inventory, while also checking the existence of the material in the current version
+     *
+     * @param index the index (= slot) where to place the item
+     * @param item  the item to place
+     * @return {@code true} if the item could be placed, otherwise {@code false}
+     * @see InventoryUtil#setItemChecked(PlotInventory, int, PlotItemStack)
+     * @since TODO
+     */
+    public boolean setItemChecked(int index, PlotItemStack item) {
+        if (!this.inventoryUtil.setItemChecked(this, index, item)) {
+            return false;
+        }
         this.items[index] = item;
-        this.inventoryUtil.setItem(this, index, item);
+        return true;
     }
 
     public PlotItemStack getItem(int index) {

Core/src/main/java/com/plotsquared/core/plot/PlotItemStack.java

@@ -46,7 +46,21 @@ public class PlotItemStack {
             final String id, final int amount, final String name,
             final String... lore
     ) {
-        this.type = ItemTypes.get(id);
+        this(ItemTypes.get(id), amount, name, lore);
+    }
+
+    /**
+     * @param type   The item type
+     * @param amount Amount of items in the stack
+     * @param name   The display name of the item stack
+     * @param lore   The item stack lore
+     * @since TODO
+     */
+    public PlotItemStack(
+            final ItemType type, final int amount, final String name,
+            final String... lore
+    ) {
+        this.type = type;
         this.amount = amount;
         this.name = name;
         this.lore = lore;

Core/src/main/java/com/plotsquared/core/util/InventoryUtil.java

@@ -38,11 +38,33 @@ public abstract class InventoryUtil {
 
     public abstract void close(final PlotInventory inv);
 
-    public abstract void setItem(
+    /**
+     * Attempts to set an item into a {@link PlotInventory} while also checking the existence of the material
+     *
+     * @param plotInventory The inventory where the item should be placed
+     * @param index The index where to place the item
+     * @param item The item to place into the inventory
+     * @return {@code true} if the item could be placed, {@code false} otherwise (e.g. item not available in current version)
+     * @since TODO
+     */
+    public abstract boolean setItemChecked(
             final PlotInventory plotInventory, final int index,
             final PlotItemStack item
     );
 
+    /**
+     * Attempts to set an item into a {@link PlotInventory}
+     *
+     * @param plotInventory The inventory where the item should be placed
+     * @param index The index where to place the item
+     * @param item The item to place into the inventory
+     * @see #setItemChecked(PlotInventory, int, PlotItemStack)
+     */
+    public void setItem(final PlotInventory plotInventory, final int index,
+                        final PlotItemStack item) {
+        setItemChecked(plotInventory, index, item);
+    }
+
     public abstract PlotItemStack[] getItems(final PlotPlayer<?> player);
 
     public abstract boolean isOpen(final PlotInventory plotInventory);