PR c++/79503 - inherited ctor taking base class

	* call.c (add_function_candidate): Also check that
	DECL_INHERITED_CTOR_BASE is reference-related to the parameter type.

From-SVN: r245586

gcc/cp/ChangeLog

+2017-02-19  Jason Merrill  <jason@redhat.com>
+
+	PR c++/79503 - inherited ctor taking base class
+	* call.c (add_function_candidate): Also check that
+	DECL_INHERITED_CTOR_BASE is reference-related to the parameter type.
+
 2017-02-19  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/79380

gcc/cp/call.c

@@ -2057,7 +2057,9 @@ add_function_candidate (struct z_candidate **candidates,
     {
       tree ptype = non_reference (TREE_VALUE (parmlist));
       tree dtype = DECL_CONTEXT (fn);
-      if (reference_related_p (ptype, dtype))
+      tree btype = DECL_INHERITED_CTOR_BASE (fn);
+      if (reference_related_p (ptype, dtype)
+	  && reference_related_p (btype, ptype))
 	{
 	  viable = false;
 	  reason = inherited_ctor_rejection ();

gcc/testsuite/g++.dg/cpp0x/inh-ctor26.C

+// PR c++/79503
+// { dg-do compile { target c++11 } }
+
+struct payload {};
+
+struct base: private payload {
+    base(payload) {}
+};
+
+struct derived: base {
+    using base::base;
+};
+
+int main()
+{
+    payload data;
+    // error: no matching function for call to 'derived::derived(payload&)'
+    // note: candidate: base::base(payload)
+    // note:   an inherited constructor is not a candidate for initialization from an expression of the same or derived type
+    derived demo(data);
+}