re PR libstdc++/53515 (InputIterator version std::advance needs negative check)

2012-09-26  Akira Takahashi  <faithandbrave@gmail.com>

	PR libstdc++/53515
	* include/bits/stl_iterator_base_funcs.h (__advance(_InputIterator&,
	_Distance, input_iterator_tag)): Add _GLIBCXX_DEBUG_ASSERT(__n >= 0).

From-SVN: r191784

libstdc++-v3/ChangeLog

+2012-09-26  Akira Takahashi  <faithandbrave@gmail.com>
+
+	PR libstdc++/53515
+	* include/bits/stl_iterator_base_funcs.h (__advance(_InputIterator&,
+	_Distance, input_iterator_tag)): Add _GLIBCXX_DEBUG_ASSERT(__n >= 0).
+
 2012-09-26  Ulrich Drepper  <drepper@gmail.com>
 
 	Optimize bulk mode for normal_distribution<double> for SSE3.

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

 // Functions used by iterators -*- C++ -*-
 
-// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
-// Free Software Foundation, Inc.
+// Copyright (C) 2001-2012 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
@@ -63,6 +62,7 @@
 #pragma GCC system_header
 
 #include <bits/concept_check.h>
+#include <debug/debug.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -124,6 +124,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       // concept requirements
       __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
+      _GLIBCXX_DEBUG_ASSERT(__n >= 0);
       while (__n--)
 	++__i;
     }