1 files changed, 18 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/lookup/koenig12.C b/gcc/testsuite/g++.dg/lookup/koenig12.C
new file mode 100644
index 000000000..c13589939
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/koenig12.C
@@ -0,0 +1,18 @@
+// PR c++/41305
+// We got into infinite recursion instantiating the B<U> series.
+
+template <class T> struct A { };
+template <class T, class U = A<T> > struct B;
+template <class T> struct C { };
+
+template <class T, class U> struct B: C<B<U> >
+{
+  friend void f(B) { }
+};
+
+B<int> b;
+
+int main()
+{
+  f(b);
+}