From 88c94cc987b327cf7d12ac52e5ff62b7da052804 Mon Sep 17 00:00:00 2001
From: Megan Marsh <megan@hashicorp.com>
Date: Wed, 17 Jun 2020 02:04:45 -0700
Subject: [PATCH] Fix 8904 (#9435)

---
 builder/virtualbox/common/driver_4_2.go       |  2 +-
 builder/virtualbox/vm/step_create_snapshot.go | 24 +++++++++++--------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/builder/virtualbox/common/driver_4_2.go b/builder/virtualbox/common/driver_4_2.go
index a10d45871..b710720dc 100644
--- a/builder/virtualbox/common/driver_4_2.go
+++ b/builder/virtualbox/common/driver_4_2.go
@@ -325,7 +325,7 @@ func (d *VBox42Driver) LoadSnapshots(vmName string) (*VBoxSnapshot, error) {
 	var rootNode *VBoxSnapshot
 	stdoutString, err := d.VBoxManageWithOutput("snapshot", vmName, "list", "--machinereadable")
 	if stdoutString == "This machine does not have any snapshots" {
-		return rootNode, fmt.Errorf("VM %s does not have any snapshots.", vmName)
+		return rootNode, nil
 	}
 	if nil != err {
 		return nil, err
diff --git a/builder/virtualbox/vm/step_create_snapshot.go b/builder/virtualbox/vm/step_create_snapshot.go
index 95c676069..8252c6f82 100644
--- a/builder/virtualbox/vm/step_create_snapshot.go
+++ b/builder/virtualbox/vm/step_create_snapshot.go
@@ -40,18 +40,22 @@ func (s *StepCreateSnapshot) Run(_ context.Context, state multistep.StateBag) mu
 			return multistep.ActionHalt
 		}
 
-		currentSnapshot := snapshotTree.GetCurrentSnapshot()
-		targetSnapshot := currentSnapshot.GetChildWithName(s.TargetSnapshot)
-		if nil != targetSnapshot {
-			log.Printf("Deleting existing target snapshot %s", s.TargetSnapshot)
-			err = driver.DeleteSnapshot(s.Name, targetSnapshot)
-			if nil != err {
-				err = fmt.Errorf("Unable to delete snapshot %s from VM %s: %s", s.TargetSnapshot, s.Name, err)
-				state.Put("error", err)
-				ui.Error(err.Error())
-				return multistep.ActionHalt
+		// Remove any snapshot with the target's name, if present.
+		if snapshotTree != nil {
+			currentSnapshot := snapshotTree.GetCurrentSnapshot()
+			targetSnapshot := currentSnapshot.GetChildWithName(s.TargetSnapshot)
+			if nil != targetSnapshot {
+				log.Printf("Deleting existing target snapshot %s", s.TargetSnapshot)
+				err = driver.DeleteSnapshot(s.Name, targetSnapshot)
+				if nil != err {
+					err = fmt.Errorf("Unable to delete snapshot %s from VM %s: %s", s.TargetSnapshot, s.Name, err)
+					state.Put("error", err)
+					ui.Error(err.Error())
+					return multistep.ActionHalt
+				}
 			}
 		}
+
 		err = driver.CreateSnapshot(s.Name, s.TargetSnapshot)
 		if err != nil {
 			err := fmt.Errorf("Error creating snaphot VM: %s", err)