global: make sure to check service before checking service->port to prevent crashes

1 files changed, 2 insertions, 3 deletions

diff --git a/src/mobilebackup.c b/src/mobilebackup.c
index ab4dec0..aae4b06 100644
--- a/src/mobilebackup.c
+++ b/src/mobilebackup.c
@@ -72,10 +72,9 @@ static mobilebackup_error_t mobilebackup_error(device_link_service_error_t err)
  *     or more parameters are invalid, or DEVICE_LINK_SERVICE_E_BAD_VERSION if
  *     the mobilebackup version on the device is newer.
  */
-mobilebackup_error_t mobilebackup_client_new(idevice_t device, lockdownd_service_descriptor_t service,
-                                                   mobilebackup_client_t * client)
+mobilebackup_error_t mobilebackup_client_new(idevice_t device, lockdownd_service_descriptor_t service, mobilebackup_client_t * client)
 {
-        if (!device || service->port == 0 || !client || *client)
+        if (!device || !service || service->port == 0 || !client || *client)
                 return MOBILEBACKUP_E_INVALID_ARG;
 
         device_link_service_client_t dlclient = NULL;