From ecc4cc0459dc3df7bdb74edddfc4fbe9b9c1e880 Mon Sep 17 00:00:00 2001
From: ninehous <hasc345@gmail.com>
Date: Thu, 31 Jul 2014 19:31:38 +0300
Subject: [PATCH] Fixes #1956

I did some thinking and realized that the intended behavior would probably be allowing the placement of a blank blueprint without anything happening. That is the same behavior of the builder has I think it should be the same.
---
 common/buildcraft/builders/TileConstructionMarker.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/buildcraft/builders/TileConstructionMarker.java b/common/buildcraft/builders/TileConstructionMarker.java
index 5bf93e29..3b46b6f0 100755
--- a/common/buildcraft/builders/TileConstructionMarker.java
+++ b/common/buildcraft/builders/TileConstructionMarker.java
@@ -85,7 +85,7 @@ public class TileConstructionMarker extends TileBuildCraft implements IBuildingI
 			return;
 		}
 
-		if (itemBlueprint != null && bluePrintBuilder == null) {
+		if (itemBlueprint != null && ItemBlueprint.getId(itemBlueprint) != null && bluePrintBuilder == null) {
 			bluePrintBuilder = new BptBuilderBlueprint((Blueprint) ItemBlueprint.loadBlueprint(itemBlueprint),
 					worldObj, xCoord, yCoord, zCoord);
 			bptContext = bluePrintBuilder.getContext();