Fix invalid calls to 1.12 methods

src/main/java/me/libraryaddict/disguise/disguisetypes/FlagWatcher.java

@@ -729,30 +729,7 @@ public class FlagWatcher {
             return;
 
         if (itemStack == null && getDisguise().getEntity() instanceof LivingEntity) {
-            EntityEquipment equip = ((LivingEntity) getDisguise().getEntity()).getEquipment();
-
-            switch (slot) {
-                case HAND:
-                    itemStack = equip.getItemInMainHand();
-                    break;
-                case OFF_HAND:
-                    itemStack = equip.getItemInOffHand();
-                    break;
-                case HEAD:
-                    itemStack = equip.getHelmet();
-                    break;
-                case CHEST:
-                    itemStack = equip.getChestplate();
-                    break;
-                case LEGS:
-                    itemStack = equip.getLeggings();
-                    break;
-                case FEET:
-                    itemStack = equip.getBoots();
-                    break;
-                default:
-                    break;
-            }
+            itemStack = ReflectionManager.getEquipment(slot, getDisguise().getEntity());
         }
 
         Object itemToSend = ReflectionManager.getNmsItem(itemStack);

src/main/java/me/libraryaddict/disguise/utilities/DisguiseUtilities.java

@@ -46,8 +46,10 @@ import org.bukkit.*;
 import org.bukkit.boss.KeyedBossBar;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.*;
+import org.bukkit.inventory.EntityEquipment;
 import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.potion.PotionEffect;
 import org.bukkit.scheduler.BukkitRunnable;
@@ -2024,6 +2026,28 @@ public class DisguiseUtilities {
         return list.toArray(new String[0]);
     }
 
+
+    public static ItemStack getSlot(PlayerInventory equip, EquipmentSlot slot) {
+        switch (slot) {
+            case HAND:
+                return equip.getItemInMainHand();
+            case OFF_HAND:
+                return equip.getItemInOffHand();
+            case HEAD:
+                return equip.getHelmet();
+            case CHEST:
+                return equip.getChestplate();
+            case LEGS:
+                return equip.getLeggings();
+            case FEET:
+                return equip.getBoots();
+            default:
+                break;
+        }
+
+        return null;
+    }
+
     /**
      * Sends the self disguise to the player
      */
@@ -2122,11 +2146,11 @@ public class DisguiseUtilities {
                         manager.createPacketConstructor(Server.ENTITY_EQUIPMENT, 0, list).createPacket(0, list));
             } else {
                 for (EquipmentSlot slot : EquipmentSlot.values()) {
+                    Object item = ReflectionManager.getNmsItem(getSlot(player.getInventory(), slot));
+
                     sendSelfPacket(player, manager.createPacketConstructor(Server.ENTITY_EQUIPMENT, 0,
-                            ReflectionManager.createEnumItemSlot(slot),
-                            ReflectionManager.getNmsItem(player.getInventory().getItem(slot)))
-                            .createPacket(player.getEntityId(), ReflectionManager.createEnumItemSlot(slot),
-                                    ReflectionManager.getNmsItem(player.getInventory().getItem(slot))));
+                            ReflectionManager.createEnumItemSlot(slot), item)
+                            .createPacket(player.getEntityId(), ReflectionManager.createEnumItemSlot(slot), item));
                 }
             }
 

src/main/java/me/libraryaddict/disguise/utilities/reflection/ReflectionManager.java

@@ -1121,7 +1121,9 @@ public class ReflectionManager {
                 Method toMinecraft = getCraftMethod("util.CraftMagicNumbers", "getMaterialFromInternalName",
                         String.class);
 
-                return (Material) toMinecraft.invoke(null, name);
+                Object instance = toMinecraft.getDeclaringClass().getField("INSTANCE").get(null);
+
+                return (Material) toMinecraft.invoke(instance, name);
             }
 
             Object mcKey = getNmsConstructor("MinecraftKey", String.class).newInstance(name);
@@ -1140,7 +1142,12 @@ public class ReflectionManager {
             return (Material) getMaterial.invoke(null, item);
         }
         catch (Exception ex) {
+            DisguiseUtilities.getLogger().severe("Error when trying to convert '" + name + "' into a Material");
             ex.printStackTrace();
+
+            if (ex.getCause() != null) {
+                ex.getCause().printStackTrace();
+            }
         }
 
         return null;