+
+# This works around a buggy version in autoconf <= 2.69.
+# See <https://lists.gnu.org/r/autoconf/2016-08/msg00014.html>
+
+m4_version_prereq([2.70], [], [
+
+# This is taken from the following Autoconf patch:
+# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=e17a30e987d7ee695fb4294a82d987ec3dc9b974
+
+m4_undefine([AC_HEADER_MAJOR])
+AC_DEFUN([AC_HEADER_MAJOR],
+[AC_CHECK_HEADERS_ONCE([sys/types.h])
+AC_CHECK_HEADER([sys/mkdev.h],
+ [AC_DEFINE([MAJOR_IN_MKDEV], [1],
+ [Define to 1 if `major', `minor', and `makedev' are declared in
+ <mkdev.h>.])])
+if test $ac_cv_header_sys_mkdev_h = no; then
+ AC_CHECK_HEADER([sys/sysmacros.h],
+ [AC_DEFINE([MAJOR_IN_SYSMACROS], [1],
+ [Define to 1 if `major', `minor', and `makedev' are declared in
+ <sysmacros.h>.])])
+fi
+])
+
+])