PR c++/89212 - ICE converting nullptr to pointer-to-member-function.

	* pt.c (tsubst_copy_and_build) <case CONSTRUCTOR>: Return early for
	null member pointer value.

	* g++.dg/cpp0x/nullptr40.C: New test.
	* g++.dg/cpp0x/nullptr41.C: New test.

From-SVN: r268781

gcc/cp/ChangeLog

+2019-02-11  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/89212 - ICE converting nullptr to pointer-to-member-function.
+	* pt.c (tsubst_copy_and_build) <case CONSTRUCTOR>: Return early for
+	null member pointer value.
+
 2019-02-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/88977

gcc/cp/pt.c

@@ -19253,6 +19253,12 @@ tsubst_copy_and_build (tree t,
 	   looked up by digest_init.  */
 	process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
 
+	if (null_member_pointer_value_p (t))
+	  {
+	    gcc_assert (same_type_p (type, TREE_TYPE (t)));
+	    RETURN (t);
+	  }
+
 	n = vec_safe_copy (CONSTRUCTOR_ELTS (t));
         newlen = vec_safe_length (n);
 	FOR_EACH_VEC_SAFE_ELT (n, idx, ce)

gcc/testsuite/ChangeLog

+2019-02-11  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/89212 - ICE converting nullptr to pointer-to-member-function.
+	* g++.dg/cpp0x/nullptr40.C: New test.
+	* g++.dg/cpp0x/nullptr41.C: New test.
+
 2019-02-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/88977

gcc/testsuite/g++.dg/cpp0x/nullptr40.C

+// PR c++/89212
+// { dg-do compile { target c++11 } }
+
+template <int, typename T> using enable_if_t = int;
+
+template<class X, void(X::*foo)() = nullptr>
+struct p
+{
+    template<void(X::*fun)() = foo, typename T = enable_if_t<nullptr == fun, int>>
+    p(T) { }
+    p() = default;
+};
+
+struct A
+{
+    p<A> i = 1;
+    void bar();
+    p<A, &A::bar> j;
+};

gcc/testsuite/g++.dg/cpp0x/nullptr41.C

+// PR c++/89212
+// { dg-do compile { target c++11 } }
+
+template <int, typename T> using enable_if_t = int;
+
+template<typename U, typename W, typename Y, class X, W(X::*foo)() = nullptr>
+struct p
+{
+    template<U(Y::*fun)() = foo, typename T = enable_if_t<nullptr == fun, int>>
+    p(T) { }
+    p() = default;
+};
+
+struct A
+{
+    p<void, void, A, A> i = 1;
+    void bar();
+    p<void, void, A, A, &A::bar> j;
+};