Index: include/debug/vector
===================================================================
--- include/debug/vector	(revision 135136)
+++ include/debug/vector	(working copy)
@@ -1,6 +1,6 @@
 // Debugging vector implementation -*- C++ -*-
 
-// Copyright (C) 2003, 2004, 2005, 2006, 2007
+// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
 // Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
@@ -443,7 +443,7 @@
       bool
       _M_requires_reallocation(size_type __elements)
       {
-#ifdef _GLIBCXX_DEBUG_PEDANTIC
+#ifndef _GLIBCXX_DEBUG_PEDANTIC
 	return __elements > this->capacity();
 #else
 	return __elements > _M_guaranteed_capacity;
Index: testsuite/23_containers/vector/debug_mode_requires_reallocation.cc
===================================================================
--- testsuite/23_containers/vector/debug_mode_requires_reallocation.cc	(revision 0)
+++ testsuite/23_containers/vector/debug_mode_requires_reallocation.cc	(revision 0)
@@ -0,0 +1,51 @@
+// Copyright (C) 2008 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+// { dg-options "-D_GLIBCXX_DEBUG" }
+
+#include <vector>
+#include <algorithm>
+#include <iterator>
+
+// http://gcc.gnu.org/ml/libstdc++/2008-05/msg00039.html
+void test01()
+{
+  typedef std::vector<unsigned> array_t;
+  typedef std::back_insert_iterator<array_t> bii_t;
+
+  array_t a;
+
+  // Push 5 elements.
+  a.push_back(0);
+  a.push_back(1);
+  a.push_back(2);
+  a.push_back(3);
+  a.push_back(4);
+  // Ensure that there is enough space for other two elements.
+  // (2 + 5 = 7)
+  if (a.capacity() < 7)
+    a.reserve(7);
+  // Add two new elements.
+  std::copy(a.begin(), a.begin() + 2, bii_t(a));
+} 
+
+int main()
+{
+  test01();
+  return 0;
+}