add another failing test for remote.State lineage

Want to make sure we don't hit this again.

backend/remote-state/inmem/backend_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/hashicorp/terraform/backend"
 	"github.com/hashicorp/terraform/state/remote"
+	"github.com/hashicorp/terraform/terraform"
 )
 
 func TestBackend_impl(t *testing.T) {
@@ -49,3 +50,41 @@ func TestBackendLocked(t *testing.T) {
 
 	backend.TestBackend(t, b1, b2)
 }
+
+// use the this backen to test the remote.State implementation
+func TestRemoteState(t *testing.T) {
+	defer Reset()
+	b := backend.TestBackendConfig(t, New(), nil)
+
+	workspace := "workspace"
+
+	// create a new workspace in this backend
+	s, err := b.State(workspace)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// force overwriting the remote state
+	newState := terraform.NewState()
+
+	if err := s.WriteState(newState); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := s.PersistState(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := s.RefreshState(); err != nil {
+		t.Fatal(err)
+	}
+
+	savedState := s.State()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if savedState.Lineage != newState.Lineage {
+		t.Fatal("saved state has incorrect lineage")
+	}
+}