--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/init/pr42844.C	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,56 @@
+// PR c++/42844
+// { dg-do compile }
+
+struct A
+{
+  A(){}
+};
+
+struct B : A { int i; }; // { dg-message "user-provided default constructor" }
+
+struct C : A { int i; }; // { dg-message "user-provided default constructor" }
+
+struct D : B { D() {} };
+
+struct E { int i; }; // { dg-message "user-provided default constructor" }
+
+template <class T>
+struct F : A { T t; }; // { dg-message "user-provided default constructor" }
+
+template <class T>
+struct G { T t; }; // { dg-message "user-provided default constructor" }
+
+void f ()
+{
+  B const b;    // { dg-error "uninitialized const" }
+  extern B const bext;
+
+  C const c[ 1 ]; // { dg-error "uninitialized const" }
+  extern C const cext[ 1 ];
+
+  D const d;
+  extern D const dext;
+
+  E const e;	// { dg-error "uninitialized const" }
+  extern E const eext;
+
+  F<int> const f; // { dg-error "uninitialized const" }
+  extern F<int> const fext;
+
+  G<int> const g; // { dg-error "uninitialized const" }
+  extern G<int> const gext;
+}
+
+struct H { int i; }; // { dg-message "user-provided default constructor" }
+
+struct I : A { int i; }; // { dg-message "user-provided default constructor" }
+
+template <class T>
+void g ()
+{
+  T const t; // { dg-error "uninitialized const" }
+  extern T const text;
+}
+
+template void g<H> ();
+template void g<I> ();