1.13.2 fix round 3.. or 4

src/main/java/com/gmail/nossr50/listeners/InventoryListener.java

@@ -383,6 +383,10 @@ public class InventoryListener implements Listener {
 
     @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
     public void onInventoryClickEvent(InventoryClickEvent event) {
+        if(event.getCurrentItem() == null) {
+            return;
+        }
+
         SkillUtils.removeAbilityBuff(event.getCurrentItem());
         if (event.getAction() == InventoryAction.HOTBAR_SWAP) {
             if(isOutsideWindowClick(event))
@@ -391,7 +395,7 @@ public class InventoryListener implements Listener {
             PlayerInventory playerInventory = event.getWhoClicked().getInventory();
 
             if(playerInventory.getItem(event.getHotbarButton()) != null)
-                SkillUtils.removeAbilityBuff(event.getWhoClicked().getInventory().getItem(event.getHotbarButton()));
+                SkillUtils.removeAbilityBuff(playerInventory.getItem(event.getHotbarButton()));
         }
     }
 

src/main/java/com/gmail/nossr50/util/ItemUtils.java

@@ -31,7 +31,7 @@ public final class ItemUtils {
         return mcMMO.getMaterialMapStore().isBow(item.getType().getKey().getKey());
     }
 
-    public static boolean hasItemInEitherHand(Player player, Material material) {
+    public static boolean hasItemInEitherHand(@NotNull Player player, Material material) {
         return player.getInventory().getItemInMainHand().getType() == material || player.getInventory().getItemInOffHand().getType() == material;
     }
 
@@ -41,7 +41,7 @@ public final class ItemUtils {
      * @param item Item to check
      * @return true if the item is a sword, false otherwise
      */
-    public static boolean isSword(ItemStack item) {
+    public static boolean isSword(@NotNull ItemStack item) {
         return mcMMO.getMaterialMapStore().isSword(item.getType().getKey().getKey());
     }
 
@@ -51,7 +51,7 @@ public final class ItemUtils {
      * @param item Item to check
      * @return true if the item is a hoe, false otherwise
      */
-    public static boolean isHoe(ItemStack item) {
+    public static boolean isHoe(@NotNull ItemStack item) {
         return mcMMO.getMaterialMapStore().isHoe(item.getType().getKey().getKey());
     }
 
@@ -61,7 +61,7 @@ public final class ItemUtils {
      * @param item Item to check
      * @return true if the item is a shovel, false otherwise
      */
-    public static boolean isShovel(ItemStack item) {
+    public static boolean isShovel(@NotNull ItemStack item) {
         return mcMMO.getMaterialMapStore().isShovel(item.getType().getKey().getKey());
     }
 
@@ -71,7 +71,7 @@ public final class ItemUtils {
      * @param item Item to check
      * @return true if the item is an axe, false otherwise
      */
-    public static boolean isAxe(ItemStack item) {
+    public static boolean isAxe(@NotNull ItemStack item) {
         return mcMMO.getMaterialMapStore().isAxe(item.getType().getKey().getKey());
     }
 
@@ -81,7 +81,7 @@ public final class ItemUtils {
      * @param item Item to check
      * @return true if the item is a pickaxe, false otherwise
      */
-    public static boolean isPickaxe(ItemStack item) {
+    public static boolean isPickaxe(@NotNull ItemStack item) {
         return mcMMO.getMaterialMapStore().isPickAxe(item.getType().getKey().getKey());
     }
 

src/main/java/com/gmail/nossr50/util/skills/SkillUtils.java

@@ -30,6 +30,7 @@ import org.bukkit.inventory.ShapelessRecipe;
 import org.bukkit.potion.PotionEffect;
 import org.bukkit.potion.PotionEffectType;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Iterator;
 
@@ -135,6 +136,9 @@ public class SkillUtils {
         if (HiddenConfig.getInstance().useEnchantmentBuffs()) {
             ItemStack heldItem = player.getInventory().getItemInMainHand();
 
+            if(heldItem == null)
+                return;
+
             if (!ItemUtils.canBeSuperAbilityDigBoosted(heldItem)) {
                 return;
             }
@@ -200,7 +204,10 @@ public class SkillUtils {
         }
     }
 
-    public static void removeAbilityBuff(@NotNull ItemStack itemStack) {
+    public static void removeAbilityBuff(@Nullable ItemStack itemStack) {
+        if(itemStack == null)
+            return;
+
         if(!ItemUtils.canBeSuperAbilityDigBoosted(itemStack))
             return;