re PR libstdc++/26020 (std::advance() isn't stable for floating point numbers)

2006-10-17  Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/26020
	* include/bits/stl_iterator_base_funcs.h (advance): Convert
	distance parameter to iterator_traits<>::difference_type.
	* testsuite/24_iterators/26020.cc: New.

From-SVN: r117827

libstdc++-v3/ChangeLog

+2006-10-17  Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/26020
+	* include/bits/stl_iterator_base_funcs.h (advance): Convert
+	distance parameter to iterator_traits<>::difference_type.
+	* testsuite/24_iterators/26020.cc: New.
+
 2006-10-17  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* include/tr1/random.tcc: Fixup long line.

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

 // Functions used by iterators -*- C++ -*-
 
-// Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
+// 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
@@ -131,7 +132,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
   template<typename _BidirectionalIterator, typename _Distance>
     inline void
     __advance(_BidirectionalIterator& __i, _Distance __n,
-              bidirectional_iterator_tag)
+	      bidirectional_iterator_tag)
     {
       // concept requirements
       __glibcxx_function_requires(_BidirectionalIteratorConcept<
@@ -172,7 +173,8 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     advance(_InputIterator& __i, _Distance __n)
     {
       // concept requirements -- taken care of in __advance
-      std::__advance(__i, __n, std::__iterator_category(__i));
+      typename iterator_traits<_InputIterator>::difference_type __d = __n;
+      std::__advance(__i, __d, std::__iterator_category(__i));
     }
 
 _GLIBCXX_END_NAMESPACE

libstdc++-v3/testsuite/24_iterators/26020.cc

+// Copyright (C) 2006 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.
+
+// 24.3.4 Iterator operations
+
+#include <iterator>
+#include <list>
+#include <testsuite_hooks.h>
+
+//libstdc++/26020
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;  
+
+  list<int> ll;
+  ll.push_back(1);
+
+  list<int>::iterator it(ll.begin());
+
+  advance(it, 0.5);
+
+  VERIFY( it == ll.begin() );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}