Index: cp/name-lookup.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/name-lookup.c,v
retrieving revision 1.86
diff -u -p -r1.86 name-lookup.c
--- cp/name-lookup.c	5 Oct 2004 13:27:40 -0000	1.86
+++ cp/name-lookup.c	15 Oct 2004 00:22:21 -0000
@@ -3422,7 +3422,7 @@ parse_using_directive (tree namespace, t
 	{
 	  if (!toplevel_bindings_p ())
 	    error ("strong using only meaningful at namespace scope");
-	  else
+	  else if (namespace != error_mark_node)
 	    DECL_NAMESPACE_ASSOCIATIONS (namespace)
 	      = tree_cons (current_namespace, 0,
 			   DECL_NAMESPACE_ASSOCIATIONS (namespace));
Index: testsuite/g++.dg/lookup/strong-using-4.C
===================================================================
RCS file: testsuite/g++.dg/lookup/strong-using-4.C
diff -N testsuite/g++.dg/lookup/strong-using-4.C
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ testsuite/g++.dg/lookup/strong-using-4.C	15 Oct 2004 00:22:21 -0000
@@ -0,0 +1,8 @@
+// PR c++/16301
+
+// { dg-do compile }
+
+namespace NS2 
+{ 
+  using namespace NS1 __attribute__ ((strong));  // { dg-error "" }
+}