From ea17b8390f78e1edeb70045bf1f93fc4eadf6dea Mon Sep 17 00:00:00 2001
From: AlgorithmX2 <AlgorithmX2@gmail.com>
Date: Wed, 5 Oct 2016 11:04:37 -0500
Subject: [PATCH] EntityPlayerSP.isServerWorld is not to be trusted.

---
 src/main/java/mod/chiselsandbits/client/UndoTracker.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/mod/chiselsandbits/client/UndoTracker.java b/src/main/java/mod/chiselsandbits/client/UndoTracker.java
index 7c40956c..c2574d26 100644
--- a/src/main/java/mod/chiselsandbits/client/UndoTracker.java
+++ b/src/main/java/mod/chiselsandbits/client/UndoTracker.java
@@ -209,7 +209,7 @@ private boolean replaySingleAction(
 	public void beginGroup(
 			final EntityPlayer player )
 	{
-		if ( player.isServerWorld() )
+		if ( player.worldObj == null || !player.worldObj.isRemote )
 		{
 			// don't touch this stuff if your a server.
 			return;