Leave moved-from std::deque in a valid state

	PR libstdc++/67707
	* include/bits/stl_deque.h (_Deque_base::_M_move_impl): Initialize
	empty object.
	* testsuite/23_containers/deque/allocator/move.cc: Check moved-from
	deque.

From-SVN: r228090

libstdc++-v3/ChangeLog

+2015-09-24  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/67707
+	* include/bits/stl_deque.h (_Deque_base::_M_move_impl): Initialize
+	empty object.
+	* testsuite/23_containers/deque/allocator/move.cc: Check moved-from
+	deque.
+
 2015-09-23  Jonathan Wakely  <jwakely@redhat.com>
 
 	* src/filesystem/ops.cc (canonical): Simplify error handling and

libstdc++-v3/include/bits/stl_deque.h

@@ -644,6 +644,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	_Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
 	// Create an empty map that allocates using the moved-from allocator.
 	_Deque_base __empty{__alloc};
+	__empty._M_initialize_map(0);
 	// Now safe to modify current allocator and perform non-throwing swaps.
 	_Deque_impl __ret{std::move(_M_get_Tp_allocator())};
 	_M_impl._M_swap_data(__ret);

libstdc++-v3/testsuite/23_containers/deque/allocator/move.cc

@@ -36,6 +36,11 @@ void test01()
   VERIFY(1 == v1.get_allocator().get_personality());
   VERIFY(1 == v2.get_allocator().get_personality());
   VERIFY( it == v2.begin() );
+
+  // PR libstdc++/67707
+  VERIFY( v1.size() == 0 );
+  v1 = test_type();
+  VERIFY( v1.size() == 0 );
 }
 
 void test02()
@@ -47,6 +52,11 @@ void test02()
   test_type v2(std::move(v1), alloc_type(2));
   VERIFY(1 == v1.get_allocator().get_personality());
   VERIFY(2 == v2.get_allocator().get_personality());
+
+  // PR libstdc++/67707
+  VERIFY( v1.size() == 0 );
+  v1 = test_type();
+  VERIFY( v1.size() == 0 );
 }
 
 int main()