From 65ba053aee248f6b3175f1b0c3d08ba65d2dd648 Mon Sep 17 00:00:00 2001
From: StevenLawson <steven@smlawson.com>
Date: Sun, 15 Sep 2013 14:11:36 -0400
Subject: [PATCH] Wrapped rollback with a Callable to make sure that it
 executes on the Bukkit thread.

Saw this in a log:

java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:819)
	at java.util.ArrayList$Itr.next(ArrayList.java:791)
	at me.StevenLawson.TotalFreedomMod.TFM_RollbackManager.rollback(TFM_RollbackManager.java:94)
	at me.StevenLawson.TotalFreedomMod.Commands.Command_gtfo.run(Command_gtfo.java:51)
---
 .../TotalFreedomMod/TFM_RollbackManager.java  | 78 ++++++++++++-------
 1 file changed, 48 insertions(+), 30 deletions(-)

diff --git a/src/me/StevenLawson/TotalFreedomMod/TFM_RollbackManager.java b/src/me/StevenLawson/TotalFreedomMod/TFM_RollbackManager.java
index 07a42a8b..76dca894 100644
--- a/src/me/StevenLawson/TotalFreedomMod/TFM_RollbackManager.java
+++ b/src/me/StevenLawson/TotalFreedomMod/TFM_RollbackManager.java
@@ -6,6 +6,8 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
+import java.util.concurrent.Callable;
+import java.util.concurrent.Future;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.Material;
@@ -84,39 +86,55 @@ public class TFM_RollbackManager
 
     public static int rollback(final String playerName)
     {
-        final List<RollbackEntry> entries = getEntriesByPlayer(playerName);
-        if (entries == null)
+        final Future<Integer> future = Bukkit.getScheduler().callSyncMethod(TotalFreedomMod.plugin, new Callable<Integer>()
+        {
+            @Override
+            public Integer call() throws Exception
+            {
+                final List<RollbackEntry> entries = getEntriesByPlayer(playerName);
+                if (entries == null)
+                {
+                    return 0;
+                }
+
+                int count = entries.size();
+                for (RollbackEntry entry : entries)
+                {
+                    if (entry != null)
+                    {
+                        entry.restore();
+                    }
+                }
+
+                if (!REMOVE_ROLLBACK_HISTORY.contains(playerName.toLowerCase()))
+                {
+                    REMOVE_ROLLBACK_HISTORY.add(playerName.toLowerCase());
+                }
+
+                new BukkitRunnable()
+                {
+                    @Override
+                    public void run()
+                    {
+                        if (REMOVE_ROLLBACK_HISTORY.contains(playerName.toLowerCase()))
+                        {
+                            REMOVE_ROLLBACK_HISTORY.remove(playerName.toLowerCase());
+                            purgeEntries(playerName);
+                        }
+                    }
+                }.runTaskLater(TotalFreedomMod.plugin, 20L * 20L);
+                return count;
+            }
+        });
+
+        try
+        {
+            return future.get();
+        }
+        catch (Exception ex)
         {
             return 0;
         }
-
-        int count = entries.size();
-        for (RollbackEntry entry : entries)
-        {
-            if (entry != null)
-            {
-                entry.restore();
-            }
-        }
-
-        if (!REMOVE_ROLLBACK_HISTORY.contains(playerName.toLowerCase()))
-        {
-            REMOVE_ROLLBACK_HISTORY.add(playerName.toLowerCase());
-        }
-
-        new BukkitRunnable()
-        {
-            @Override
-            public void run()
-            {
-                if (REMOVE_ROLLBACK_HISTORY.contains(playerName.toLowerCase()))
-                {
-                    REMOVE_ROLLBACK_HISTORY.remove(playerName.toLowerCase());
-                    purgeEntries(playerName);
-                }
-            }
-        }.runTaskLater(TotalFreedomMod.plugin, 20L * 20L);
-        return count;
     }
 
     public static int undoRollback(String playerName)