Make sure to handle cases when the backend is stopped before being initialised

diff --git a/ykcore/ykcore_libusb-1.0.c b/ykcore/ykcore_libusb-1.0.c
index 7fc9aee5a0b47c6544a0cc0336c9b3ffd0ff8740..35f7bb0c335fb0b88f4941543cd7078b85478fbd 100644 (file)
--- a/ykcore/ykcore_libusb-1.0.c
+++ b/ykcore/ykcore_libusb-1.0.c
@@ -41,6 +41,7 @@
 #define HID_SET_REPORT                 0x09
 
 static int ykl_errno;
+static int libusb_inited = 0;
 
 /*************************************************************************
  **  function _ykusb_write                                             **
@@ -135,13 +136,18 @@ int _ykusb_read(void *dev, int report_type, int report_number,
 int _ykusb_start(void)
 {
        libusb_init(NULL);
+       libusb_inited = 1;
        return 1;
 }
 
 extern int _ykusb_stop(void)
 {
-       libusb_exit(NULL);
-       return 1;
+       if (libusb_inited == 1) {
+               libusb_exit(NULL);
+               return 1;
+       }
+       yk_errno = YK_EUSBERR;
+       return 0;
 }
 
 void *_ykusb_open_device(int vendor_id, int product_id)