From f30e048afcb5160b984b76ff46858cb680d6fd5b Mon Sep 17 00:00:00 2001
From: Jef Driesen <jefdriesen@users.sourceforge.net>
Date: Thu, 11 Aug 2016 16:03:57 +0200
Subject: [PATCH] Add a configure option to build without libusb.

---
 configure.ac | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index b5aa34b..b8c25dc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -74,11 +74,17 @@ AC_MSG_RESULT([$os_win32])
 AM_CONDITIONAL([OS_WIN32], [test "$os_win32" = "yes"])
 
 # Checks for USB support.
-PKG_CHECK_MODULES([LIBUSB], [libusb-1.0], [have_libusb=yes], [have_libusb=no])
-if test "$have_libusb" = "yes"; then
-	AC_DEFINE([HAVE_LIBUSB], [1], [libusb support])
-	AC_SUBST([DEPENDENCIES], [libusb-1.0])
-fi
+AC_ARG_WITH([libusb],
+	[AS_HELP_STRING([--without-libusb],
+		[Build without the libusb library])],
+	[], [with_libusb=auto])
+AS_IF([test "x$with_libusb" != "xno"], [
+	PKG_CHECK_MODULES([LIBUSB], [libusb-1.0], [have_libusb=yes], [have_libusb=no])
+	AS_IF([test "x$have_libusb" = "xyes"], [
+		AC_DEFINE([HAVE_LIBUSB], [1], [libusb library])
+		AC_SUBST([DEPENDENCIES], [libusb-1.0])
+	])
+])
 
 # Checks for IrDA support.
 AC_CHECK_HEADERS([winsock2.h af_irda.h], [irda_win32=yes], [irda_win32=no], [