Replacing old inventory protecting with safe packet modifications using ProtocolLib.

Instead of clearing the inventory of players and storing it's contents in a file, we now prevent
the server from sending the inventory packet if the player is not logged in. The player will
see a empty inventory, but has still his items stored on the server. Therefore we don't
need to modify the player's inventory and we won't make any inventory corrupted.

Fixes Xephi/AuthMeReloaded#203,
Fixes Xephi/AuthMeReloaded#193,
Fixes Xephi/AuthMeReloaded#191,
Fixes Xephi/AuthMeReloaded#148

Remove dead code + Fix empty inventory on the unregister command

Fix NPE if ProtocolLib isn't enabled or installed

src/main/java/fr/xephi/authme/cache/limbo/LimboCache.java

@@ -11,7 +11,6 @@ import org.bukkit.Bukkit;
 import org.bukkit.GameMode;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
-import org.bukkit.inventory.ItemStack;
 
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -25,15 +24,13 @@ public class LimboCache {
     private LimboCache(AuthMe plugin) {
         this.plugin = plugin;
         this.cache = new ConcurrentHashMap<>();
-        this.playerData = new JsonCache(plugin);
+        this.playerData = new JsonCache();
     }
 
     public void addLimboPlayer(Player player) {
         String name = player.getName().toLowerCase();
         Location loc = player.getLocation();
         GameMode gameMode = player.getGameMode();
-        ItemStack[] arm;
-        ItemStack[] inv;
         boolean operator = false;
         String playerGroup = "";
         boolean flying = false;
@@ -42,12 +39,10 @@ public class LimboCache {
             final StoreInventoryEvent event = new StoreInventoryEvent(player, playerData);
             Bukkit.getServer().getPluginManager().callEvent(event);
             if (!event.isCancelled() && event.getInventory() != null && event.getArmor() != null) {
-                inv = event.getInventory();
-                arm = event.getArmor();
-            } else {
-                inv = null;
-                arm = null;
+                player.getInventory().setContents(event.getInventory());
+                player.getInventory().setArmorContents(event.getArmor());
             }
+
             DataFileCache cache = playerData.readCache(player);
             if (cache != null) {
                 playerGroup = cache.getGroup();
@@ -58,12 +53,10 @@ public class LimboCache {
             StoreInventoryEvent event = new StoreInventoryEvent(player);
             Bukkit.getServer().getPluginManager().callEvent(event);
             if (!event.isCancelled() && event.getInventory() != null && event.getArmor() != null) {
-                inv = event.getInventory();
-                arm = event.getArmor();
-            } else {
-                inv = null;
-                arm = null;
+                player.getInventory().setContents(event.getInventory());
+                player.getInventory().setArmorContents(event.getArmor());
             }
+
             operator = player.isOp();
             flying = player.isFlying();
             if (plugin.permission != null) {
@@ -93,7 +86,7 @@ public class LimboCache {
         if (player.isDead()) {
             loc = plugin.getSpawnLocation(player);
         }
-        cache.put(name, new LimboPlayer(name, loc, inv, arm, gameMode, operator, playerGroup, flying));
+        cache.put(name, new LimboPlayer(name, loc, gameMode, operator, playerGroup, flying));
     }
 
     public void addLimboPlayer(Player player, String group) {

src/main/java/fr/xephi/authme/cache/limbo/LimboPlayer.java

@@ -2,14 +2,11 @@ package fr.xephi.authme.cache.limbo;
 
 import org.bukkit.GameMode;
 import org.bukkit.Location;
-import org.bukkit.inventory.ItemStack;
 import org.bukkit.scheduler.BukkitTask;
 
 public class LimboPlayer {
 
     private String name;
-    private ItemStack[] inventory;
-    private ItemStack[] armour;
     private Location loc = null;
     private BukkitTask timeoutTaskId = null;
     private BukkitTask messageTaskId = null;
@@ -18,19 +15,6 @@ public class LimboPlayer {
     private String group = "";
     private boolean flying = false;
 
-    public LimboPlayer(String name, Location loc, ItemStack[] inventory,
-            ItemStack[] armour, GameMode gameMode, boolean operator,
-            String group, boolean flying) {
-        this.name = name;
-        this.loc = loc;
-        this.inventory = inventory;
-        this.armour = armour;
-        this.gameMode = gameMode;
-        this.operator = operator;
-        this.group = group;
-        this.flying = flying;
-    }
-
     public LimboPlayer(String name, Location loc, GameMode gameMode,
             boolean operator, String group, boolean flying) {
         this.name = name;
@@ -54,22 +38,6 @@ public class LimboPlayer {
         return loc;
     }
 
-    public ItemStack[] getArmour() {
-        return armour;
-    }
-
-    public ItemStack[] getInventory() {
-        return inventory;
-    }
-
-    public void setArmour(ItemStack[] armour) {
-        this.armour = armour;
-    }
-
-    public void setInventory(ItemStack[] inventory) {
-        this.inventory = inventory;
-    }
-
     public GameMode getGameMode() {
         return gameMode;
     }
@@ -105,5 +73,4 @@ public class LimboPlayer {
     public boolean isFlying() {
         return flying;
     }
-
 }