helper/schema: ImportState must set ID on the resource data

helper/schema/provider.go

@@ -229,6 +229,7 @@ func (p *Provider) ImportState(
 
 	// Create the data
 	data := r.Data(nil)
+	data.SetId(info.Id)
 	data.SetType(info.Type)
 
 	// Call the import function
@@ -243,5 +244,16 @@ func (p *Provider) ImportState(
 		states[i] = r.State()
 	}
 
+	// Verify that all are non-nil. If there are any nil the error
+	// isn't obvious so we circumvent that with a friendlier error.
+	for _, s := range states {
+		if s == nil {
+			return nil, fmt.Errorf(
+				"nil entry in ImportState results. This is always a bug with\n" +
+					"the resource that is being imported. Please report this as\n" +
+					"a bug to Terraform.")
+		}
+	}
+
 	return states, nil
 }

helper/schema/provider_test.go

@@ -201,6 +201,36 @@ func TestProviderValidateResource(t *testing.T) {
 	}
 }
 
+func TestProviderImportState_setsId(t *testing.T) {
+	var val string
+	stateFunc := func(d *ResourceData, meta interface{}) ([]*ResourceData, error) {
+		val = d.Id()
+		return []*ResourceData{d}, nil
+	}
+
+	p := &Provider{
+		ResourcesMap: map[string]*Resource{
+			"foo": &Resource{
+				Importer: &ResourceImporter{
+					State: stateFunc,
+				},
+			},
+		},
+	}
+
+	_, err := p.ImportState(&terraform.InstanceInfo{
+		Id:   "bar",
+		Type: "foo",
+	})
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if val != "bar" {
+		t.Fatal("should set id")
+	}
+}
+
 func TestProviderImportState_setsType(t *testing.T) {
 	var tVal string
 	stateFunc := func(d *ResourceData, meta interface{}) ([]*ResourceData, error) {