Restore check for no detected serial ports on Windows

Author: twpayne

serial_windows.go

@@ -18,7 +18,9 @@ package serial
 */
 
 import (
+	"errors"
 	"sync"
+	"syscall"
 	"time"
 
 	"golang.org/x/sys/windows"
@@ -32,7 +34,12 @@ type windowsPort struct {
 
 func nativeGetPortsList() ([]string, error) {
 	key, err := registry.OpenKey(windows.HKEY_LOCAL_MACHINE, `HARDWARE\DEVICEMAP\SERIALCOMM\`, windows.KEY_READ)
-	if err != nil {
+	switch {
+	case errors.Is(err, syscall.ERROR_FILE_NOT_FOUND):
+		// On machines with no serial ports the registry key does not exist.
+		// Return this as no serial ports instead of an error.
+		return nil, nil
+	case err != nil:
 		return nil, &PortError{code: ErrorEnumeratingPorts, causedBy: err}
 	}
 	defer key.Close()