Prevent the inevitable server lag|crashes caused by people doing a blocking operation on the main thread.

CraftBukkit-Patches/0125-Prevent-getOfflinePlayer-UUID-on-main-thread.patch

@@ -0,0 +1,21 @@
+From 199e63f001def1fb39642d5f6448544493ec37c7 Mon Sep 17 00:00:00 2001
+From: md_5 <git@md-5.net>
+Date: Sun, 30 Mar 2014 09:15:35 +1100
+Subject: [PATCH] Prevent getOfflinePlayer(UUID) on main thread.
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+index 4c089ea..8961015 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+@@ -1341,6 +1341,7 @@ public final class CraftServer implements Server {
+ 
+     // TODO: In 1.7.6+ this should just lookup the UUID-based player data filename
+     public OfflinePlayer getOfflinePlayer(UUID id) {
++        com.google.common.base.Preconditions.checkState(!Bukkit.isPrimaryThread(), "Cannot call getOfflinePlayer(UUID) on main thread, this operation is blocking!"); // Spigot
+         String name = MojangNameLookup.lookupName(id);
+         if (name == null) {
+             // This is completely wrong
+-- 
+1.8.3.2
+