re PR c++/55058 (Unexpected invalid type conversion error)

	PR c++/55058
	* pt.c (tsubst): Keep the quals when looking through a typedef.

From-SVN: r194282

gcc/cp/ChangeLog

 2012-12-06  Jason Merrill  <jason@redhat.com>
 
+	PR c++/55058
+	* pt.c (tsubst): Keep the quals when looking through a typedef.
+
 	PR c++/55249
 	* tree.c (build_vec_init_elt): Use the type of the initializer.
 

gcc/cp/pt.c

@@ -11013,8 +11013,13 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	  return r;
 	}
       else
-	/* We don't have an instantiation yet, so drop the typedef.  */
-	t = DECL_ORIGINAL_TYPE (decl);
+	{
+	  /* We don't have an instantiation yet, so drop the typedef.  */
+	  int quals = cp_type_quals (t);
+	  t = DECL_ORIGINAL_TYPE (decl);
+	  t = cp_build_qualified_type_real (t, quals,
+					    complain | tf_ignore_bad_quals);
+	}
     }
 
   if (type

gcc/testsuite/g++.dg/template/typedef40.C

+// PR c++/55058
+
+template <typename T>
+struct A { };
+
+template <typename T>
+struct B {
+  B(const A<T> T::* p);
+  typedef A<T> D;
+};
+
+template <typename T>
+B<T>::B(const D T::* p) { }
+
+struct C {
+  C() : e() {};
+
+  const A<C> e;
+};
+
+B<C> g(&C::e);