--- libusb/core.c.orig	2008-09-21 16:10:35 +0400

+++ libusb/core.c	2008-10-01 00:58:57 +0400

@@ -626,6 +626,10 @@ API_EXPORTED usb_dev_handle *usb_open(st

 API_EXPORTED int usb_close(usb_dev_handle *dev)

 {

+	if(!dev) {

+		usbi_dbg("attempt to close a non-opened (NULL) USB device. This is a bug in your application");

+		return 0;

+	}

 	usbi_dbg("");

 	libusb_close(dev->handle);

 	free(dev);