+# ------------------------------------------------------------------------------
+have_zlib=no
+AC_ARG_ENABLE(zlib, AS_HELP_STRING([--disable-zlib], [Disable optional ZLIB support]))
+if test "x$enable_zlib" != "xno"; then
+ PKG_CHECK_MODULES(ZLIB, [ zlib ],
+ [AC_DEFINE(HAVE_ZLIB, 1, [Define if ZLIB is available]) have_zlib=yes])
+ if test "x$have_zlib" = xno -a "x$enable_zlib" = xyes; then
+ AC_MSG_ERROR([*** ZLIB support requested but libraries not found])
+ fi
+fi
+AM_CONDITIONAL(HAVE_ZLIB, [test "$have_zlib" = "yes"])
+