Test /usr/X11R6/lib/X11/*.a before /usr/X11R6/lib/*.a.
The first test then fails, and short-circuiting means
that the second one is not run at all, so buildreq
does not pick up extra dependencies.

Patch by at@ (see altbug #6797 for more information.)

diff --git a/autoconf/lib/autoconf/libs.m4 b/autoconf/lib/autoconf/libs.m4
index d70babf..b44e901 100644
--- a/autoconf/lib/autoconf/libs.m4
+++ b/autoconf/lib/autoconf/libs.m4
@@ -204,8 +204,8 @@ _ACEOF
     done
     # Open Windows xmkmf reportedly sets LIBDIR instead of USRLIBDIR.
     for ac_extension in so sl a; do
-      if test ! -f "$ac_im_usrlibdir/libX11.$ac_extension" &&
-	 test -f "$ac_im_libdir/libX11.$ac_extension"; then
+      if test -f "$ac_im_libdir/libX11.$ac_extension" &&
+	 test ! -f "$ac_im_usrlibdir/libX11.$ac_extension"; then
 	ac_im_usrlibdir=$ac_im_libdir; break
       fi
     done