> + yes|no) AC_MSG_ERROR([bad value ${withval} given for
> --with-native-system-header-dir]) ;;
> + /*) ;;
> + *) AC_MSG_ERROR([--with-native-system-header-dir argument ${withval} must
> be an absolute directory]) ;;
This doesn't handle DOS-style absolute paths (like c:/Users). Not
sure if we care about '\' separators but they probably should be
checked for too (if the user can figure out how to make those work
elsewhere, we shouldn't prevent it here).
Otherwise, I'm OK with the build-specific portions of the patch (and
the djgpp-specific ones).
