--- /dev/null
+// RUN: clang-cc -fsyntax-only -verify %s
+
+// We have to avoid ADL for this test.
+
+template <unsigned N> class test {};
+
+class foo {};
+test<0> foo(foo); // expected-note {{candidate}}
+
+namespace A {
+ class foo { int x; };
+ test<1> foo(class foo);
+
+ namespace B {
+ test<2> foo(class ::foo); // expected-note {{candidate}}
+
+ void test0() {
+ using ::foo;
+
+ class foo a;
+ test<0> _ = (foo)(a);
+ }
+
+ void test1() {
+ using A::foo;
+
+ class foo a;
+ test<1> _ = (foo)(a);
+ };
+
+ void test2() {
+ class ::foo a;
+
+ // Argument-dependent lookup is ambiguous between B:: and ::.
+ test<0> _0 = foo(a); // expected-error {{call to 'foo' is ambiguous}}
+
+ // But basic unqualified lookup is not.
+ test<2> _1 = (foo)(a);
+
+ class A::foo b;
+ test<2> _2 = (foo)(b); // expected-error {{incompatible type passing}}
+ }
+ }
+}