From 7249a73f7995ea1c89020b96660332818e85e35e Mon Sep 17 00:00:00 2001
From: Martin Atkins <mart@degeneration.co.uk>
Date: Mon, 27 Aug 2018 18:14:34 -0700
Subject: [PATCH] core: Don't panic if "required replace" path doesn't resolve
 to a value

---
 terraform/eval_diff.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/terraform/eval_diff.go b/terraform/eval_diff.go
index cd8178950b..79239adf86 100644
--- a/terraform/eval_diff.go
+++ b/terraform/eval_diff.go
@@ -214,9 +214,11 @@ func (n *EvalDiff) Eval(ctx EvalContext) (interface{}, error) {
 				// the same type, but we'll allow it for robustness.
 				reqRep = append(reqRep, path)
 			}
-			eqV := plannedChangedVal.Equals(priorChangedVal)
-			if !eqV.IsKnown() || eqV.False() {
-				reqRep = append(reqRep, path)
+			if priorChangedVal != cty.NilVal {
+				eqV := plannedChangedVal.Equals(priorChangedVal)
+				if !eqV.IsKnown() || eqV.False() {
+					reqRep = append(reqRep, path)
+				}
 			}
 		}
 		if diags.HasErrors() {