+have_xz=no
+AC_ARG_ENABLE(xz, AS_HELP_STRING([--disable-xz], [Disable optional XZ support]))
+if test "x$enable_xz" != "xno"; then
+ PKG_CHECK_MODULES(XZ, [ liblzma ],
+ [AC_DEFINE(HAVE_XZ, 1, [Define if XZ is available]) have_xz=yes], have_xz=no)
+ AC_SUBST(XZ_CFLAGS)
+ AC_SUBST(XZ_LIBS)
+ if test "x$have_xz" = xno -a "x$enable_xz" = xyes; then
+ AC_MSG_ERROR([*** Xz support requested but libraries not found])
+ fi
+fi
+AM_CONDITIONAL(HAVE_XZ, [test "$have_xz" = "yes"])
+