Don't prefer "pkgsrc" versions of "MesaLib", "Xft2" etc. under

Mac OS X Leopard which ships with an uptodate version of X.org.

mk/defaults/mk.conf

@@ -1,4 +1,4 @@
-# $NetBSD: mk.conf,v 1.166 2007/11/26 22:14:13 seb Exp $
+# $NetBSD: mk.conf,v 1.167 2007/12/05 21:38:06 tron Exp $
 #
 
 # This file provides default values for variables that may be overridden
@@ -205,8 +205,13 @@ PKGSRC_RUN_TEST?=	no
 # Possible: yes, no
 # Default: no
 
+.if empty(MACHINE_PLATFORM:MDarwin-[9].*-*) || \
+    (defined(X11_TYPE) && ${X11_TYPE} != "native")
 PREFER_PKGSRC?=		MesaLib Xft2 Xrandr Xrender expat fontconfig	\
 			freetype2 glu randrproto renderproto xcursor
+.else
+PREFER_PKGSRC?=
+.endif
 PREFER_NATIVE?=		yes
 #
 # When building packages, whether to prefer the pkgsrc or native