helper/schema: record schema version on apply

We were previously only recording the schema version on refresh. This
caused the state to be incorrectly written after a `terraform apply`
causing subsequent commands to run the state through an unnecessary
migration.

helper/schema/resource.go

@@ -151,7 +151,7 @@ func (r *Resource) Apply(
 		err = r.Update(data, meta)
 	}
 
-	return data.State(), err
+	return r.recordCurrentSchemaVersion(data.State()), err
 }
 
 // Diff returns a diff of this resource and is API compatible with the
@@ -207,14 +207,7 @@ func (r *Resource) Refresh(
 		state = nil
 	}
 
-	if state != nil && r.SchemaVersion > 0 {
-		if state.Meta == nil {
-			state.Meta = make(map[string]string)
-		}
-		state.Meta["schema_version"] = strconv.Itoa(r.SchemaVersion)
-	}
-
-	return state, err
+	return r.recordCurrentSchemaVersion(state), err
 }
 
 // InternalValidate should be called to validate the structure
@@ -241,3 +234,14 @@ func (r *Resource) checkSchemaVersion(is *terraform.InstanceState) (bool, int) {
 	stateSchemaVersion, _ := strconv.Atoi(is.Meta["schema_version"])
 	return stateSchemaVersion < r.SchemaVersion, stateSchemaVersion
 }
+
+func (r *Resource) recordCurrentSchemaVersion(
+	state *terraform.InstanceState) *terraform.InstanceState {
+	if state != nil && r.SchemaVersion > 0 {
+		if state.Meta == nil {
+			state.Meta = make(map[string]string)
+		}
+		state.Meta["schema_version"] = strconv.Itoa(r.SchemaVersion)
+	}
+	return state
+}

helper/schema/resource_test.go

@@ -11,6 +11,7 @@ import (
 
 func TestResourceApply_create(t *testing.T) {
 	r := &Resource{
+		SchemaVersion: 2,
 		Schema: map[string]*Schema{
 			"foo": &Schema{
 				Type:     TypeInt,
@@ -51,6 +52,9 @@ func TestResourceApply_create(t *testing.T) {
 			"id":  "foo",
 			"foo": "42",
 		},
+		Meta: map[string]string{
+			"schema_version": "2",
+		},
 	}
 
 	if !reflect.DeepEqual(actual, expected) {
@@ -339,6 +343,7 @@ func TestResourceInternalValidate(t *testing.T) {
 
 func TestResourceRefresh(t *testing.T) {
 	r := &Resource{
+		SchemaVersion: 2,
 		Schema: map[string]*Schema{
 			"foo": &Schema{
 				Type:     TypeInt,
@@ -368,6 +373,9 @@ func TestResourceRefresh(t *testing.T) {
 			"id":  "bar",
 			"foo": "13",
 		},
+		Meta: map[string]string{
+			"schema_version": "2",
+		},
 	}
 
 	actual, err := r.Refresh(s, 42)

terraform/state.go

@@ -843,6 +843,9 @@ func (i *InstanceState) init() {
 	if i.Attributes == nil {
 		i.Attributes = make(map[string]string)
 	}
+	if i.Meta == nil {
+		i.Meta = make(map[string]string)
+	}
 	i.Ephemeral.init()
 }
 
@@ -860,6 +863,12 @@ func (i *InstanceState) deepcopy() *InstanceState {
 			n.Attributes[k] = v
 		}
 	}
+	if i.Meta != nil {
+		n.Meta = make(map[string]string, len(i.Meta))
+		for k, v := range i.Meta {
+			n.Meta[k] = v
+		}
+	}
 	return n
 }