Fixed rare case of endless loop over Inventory viewers

src/com/dre/brewery/Barrel.java

@@ -8,6 +8,7 @@ import org.apache.commons.lang.ArrayUtils;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
 import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.event.player.PlayerInteractEvent;
 import org.bukkit.inventory.Inventory;
@@ -18,6 +19,7 @@ import org.bukkit.plugin.Plugin;
 import org.bukkit.scheduler.BukkitRunnable;
 
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
 
@@ -469,9 +471,10 @@ public class Barrel implements InventoryHolder {
 	// removes a barrel, throwing included potions to the ground
 	public void remove(Block broken, Player breaker) {
 		if (inventory != null) {
-			while (!inventory.getViewers().isEmpty()) {
-				// Use while loop to fix ConcModExc
-				inventory.getViewers().get(0).closeInventory();
+			List<HumanEntity> viewers = new ArrayList(inventory.getViewers());
+			// Copy List to fix ConcModExc
+			for (HumanEntity viewer : viewers) {
+				viewer.closeInventory();
 			}
 			ItemStack[] items = inventory.getContents();
 			inventory.clear();

src/com/dre/brewery/listeners/InventoryListener.java

@@ -349,10 +349,23 @@ public class InventoryListener implements Listener {
 		barrel.clickInv(event);
 	}
 
+	//public static boolean opening = false;
+
 	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
 	public void onInventoryOpen(InventoryOpenEvent event) {
 		if (!P.use1_14) return;
 
+		/*Barrel x = null;
+		if (event.getInventory().getHolder() instanceof Barrel) {
+			x = ((Barrel) event.getInventory().getHolder());
+		}
+
+		if (!opening) {
+			opening = true;
+			Barrel finalBarrel = x;
+			P.p.getServer().getScheduler().scheduleSyncDelayedTask(P.p, () -> {finalBarrel.remove(null, null); opening = false;}, 100);
+		}*/
+
 		// Check for MC Barrel
 		if (event.getInventory().getType() == InventoryType.BARREL) {
 			Inventory inv = event.getInventory();