From 59bd1a22f4e51e6f600525e66ac73fe857b03afa Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 8 Nov 2016 23:06:12 -0800
Subject: [PATCH] helper/diff: handle unknownvariablevalue

---
 helper/diff/resource_builder.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/helper/diff/resource_builder.go b/helper/diff/resource_builder.go
index 18d010017b..2eb3806a1d 100644
--- a/helper/diff/resource_builder.go
+++ b/helper/diff/resource_builder.go
@@ -3,6 +3,7 @@ package diff
 import (
 	"strings"
 
+	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/flatmap"
 	"github.com/hashicorp/terraform/terraform"
 )
@@ -94,7 +95,7 @@ func (b *ResourceBuilder) Diff(
 
 			// If this key is in the cleaned config, then use that value
 			// because it'll have its variables properly interpolated
-			if cleanV, ok := flatConfig[k]; ok {
+			if cleanV, ok := flatConfig[k]; ok && cleanV != config.UnknownVariableValue {
 				v = cleanV
 				originalV = v