helper/schema: diffing maps that are computed should not result in

change

helper/schema/schema.go

@@ -580,6 +580,11 @@ func (m schemaMap) diffMap(
 		return fmt.Errorf("%s: %s", k, err)
 	}
 
+	// If the new map is nil and we're computed, then ignore it.
+	if n == nil && schema.Computed {
+		return nil
+	}
+
 	// Now we compare, preferring values from the config map
 	for k, v := range configMap {
 		old := stateMap[k]

helper/schema/schema_test.go

@@ -1191,6 +1191,27 @@ func TestSchemaMap_Diff(t *testing.T) {
 			Err: false,
 		},
 
+		{
+			Schema: map[string]*Schema{
+				"vars": &Schema{
+					Type:     TypeMap,
+					Computed: true,
+				},
+			},
+
+			State: &terraform.InstanceState{
+				Attributes: map[string]string{
+					"vars.foo": "bar",
+				},
+			},
+
+			Config: nil,
+
+			Diff: nil,
+
+			Err: false,
+		},
+
 		{
 			Schema: map[string]*Schema{
 				"config_vars": &Schema{