From bfa5e7f81143b2380547fe37067d5e0ec04f49e8 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Tue, 25 Jun 2019 16:43:57 -0400
Subject: [PATCH] actual value may be unknown in nested list

When checking AssertObjectCompatible, we need to allow for a possible
unkown nested list block, just as we did for a set in 0b2cc62.
---
 plans/objchange/compatible.go      |  2 +-
 plans/objchange/compatible_test.go | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/plans/objchange/compatible.go b/plans/objchange/compatible.go
index 8b7ef43fd..8a74c07fe 100644
--- a/plans/objchange/compatible.go
+++ b/plans/objchange/compatible.go
@@ -84,7 +84,7 @@ func assertObjectCompatible(schema *configschema.Block, planned, actual cty.Valu
 			// whether there are dynamically-typed attributes inside. However,
 			// both support a similar-enough API that we can treat them the
 			// same for our purposes here.
-			if !plannedV.IsKnown() || plannedV.IsNull() || actualV.IsNull() {
+			if !plannedV.IsKnown() || !actualV.IsKnown() || plannedV.IsNull() || actualV.IsNull() {
 				continue
 			}
 
diff --git a/plans/objchange/compatible_test.go b/plans/objchange/compatible_test.go
index e8af5458b..2841ec26b 100644
--- a/plans/objchange/compatible_test.go
+++ b/plans/objchange/compatible_test.go
@@ -1135,6 +1135,32 @@ func TestAssertObjectCompatible(t *testing.T) {
 			}),
 			nil,
 		},
+		{
+			&configschema.Block{
+				BlockTypes: map[string]*configschema.NestedBlock{
+					"block": {
+						Nesting: configschema.NestingList,
+						Block: configschema.Block{
+							Attributes: map[string]*configschema.Attribute{
+								"foo": {
+									Type:     cty.String,
+									Required: true,
+								},
+							},
+						},
+					},
+				},
+			},
+			cty.ObjectVal(map[string]cty.Value{
+				"block": cty.EmptyObjectVal,
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"block": cty.UnknownVal(cty.List(cty.Object(map[string]cty.Type{
+					"foo": cty.String,
+				}))),
+			}),
+			nil,
+		},
 	}
 
 	for i, test := range tests {