Return error for empty target

scan.go

@@ -1307,6 +1307,10 @@ func stringToCm(token string) (e, m uint8, ok bool) {
 }
 
 func toAbsoluteName(name, origin string) (absolute string, ok bool) {
+	if name == "\n" {
+		return "", false
+	}
+
 	// check for an explicit origin reference
 	if name == "@" {
 		// require a nonempty origin

scan_test.go

@@ -226,6 +226,22 @@ func TestZoneParserAddressAAAA(t *testing.T) {
 	}
 }
 
+func TestZoneParserTargetBad(t *testing.T) {
+	records := []string{
+		"bad.example.org. CNAME ; bad cname",
+		"bad.example.org. HTTPS 10 ; bad https",
+		"bad.example.org. MX 10 ; bad mx",
+		"bad.example.org. SRV 1 0 80 ; bad srv",
+	}
+
+	for _, record := range records {
+		const expect = "bad "
+		if got, err := NewRR(record); err == nil || !strings.Contains(err.Error(), expect) {
+			t.Errorf("NewRR(%v) = %v, want err to contain %q", record, got, expect)
+		}
+	}
+}
+
 func TestZoneParserAddressBad(t *testing.T) {
 	records := []string{
 		"1.bad.example.org. 600 IN A ::1",