fix broken test

builder/virtualbox/common/step_type_boot_command.go

@@ -108,24 +108,24 @@ func (s *StepTypeBootCommand) Run(state multistep.StateBag) multistep.StepAction
 func (*StepTypeBootCommand) Cleanup(multistep.StateBag) {}
 
 // Gather scancodes to send to console efficiently.
-func gathercodes(codes []string) []string {
-	result := make([]string, 0, len(codes))
-	begin := 0
-	end := 0
-	for pos, code := range codes {
-		if strings.HasPrefix(code, "wait") {
-			if pos > begin {
-				result = append(result, strings.Join(codes[begin:end+1], " "))
-			}
-			result = append(result, code)
-			begin = pos + 1
+func gathercodes(codes []string) (gathered []string) {
+	working := []string{}
+	pushWorking := func() {
+		if len(working) > 0 {
+			gathered = append(gathered, strings.Join(working, " "))
+			working = []string{}
 		}
-		end = pos
 	}
-	if end > begin {
-		result = append(result, strings.Join(codes[begin:end+1], " "))
+	for _, code := range codes {
+		if strings.HasPrefix(code, "wait") {
+			pushWorking()
+			gathered = append(gathered, code)
+		} else {
+			working = append(working, code)
+		}
 	}
-	return result
+	pushWorking()
+	return
 }
 
 func scancodes(message string) []string {

builder/virtualbox/common/step_type_boot_command_test.go

@@ -11,6 +11,8 @@ func TestStepTypeBootCommand_gather(t *testing.T) {
 		{"02", "82", "03", "83"},
 		{"wait5", "wait1", "wait10"},
 		{"wait5", "02", "82", "03", "83", "wait1", "wait10"},
+		{"wait1"},
+		{"01"},
 	}
 
 	expected := [][]string{
@@ -18,12 +20,14 @@ func TestStepTypeBootCommand_gather(t *testing.T) {
 		{"02 82 03 83"},
 		{"wait5", "wait1", "wait10"},
 		{"wait5", "02 82 03 83", "wait1", "wait10"},
+		{"wait1"},
+		{"01"},
 	}
 
 	for i, data := range input {
-		if !reflect.DeepEqual(gathercodes(data), expected[i]) {
-			t.Fatalf("%#v did not equal expected %#v", data, expected[i])
+		gathered := gathercodes(data)
+		if !reflect.DeepEqual(gathered, expected[i]) {
+			t.Fatalf("%#v did not equal expected %#v", gathered, expected[i])
 		}
 	}
-
 }