re PR libstdc++/34636 (Parallel sort fails)

2008-01-01  Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/34636
	* include/parallel/algobase.h (lexicographical_compare_switch(...,
	random_access_iterator_tag, random_access_iterator_tag)): Careful
	with undereferenceable iterators.
	* testsuite/25_algorithms/sort/34636.cc: New.

From-SVN: r131245

libstdc++-v3/ChangeLog

+2008-01-01  Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/34636
+	* include/parallel/algobase.h (lexicographical_compare_switch(...,
+	random_access_iterator_tag, random_access_iterator_tag)): Careful
+	with undereferenceable iterators.
+	* testsuite/25_algorithms/sort/34636.cc: New.
+
 2007-12-30  Paolo Carlini  <pcarlini@suse.de>
 
 	* include/std/tuple (_Tuple_impl<>::_Tuple_impl(typename

libstdc++-v3/include/parallel/algobase.h

@@ -215,13 +215,7 @@ namespace __parallel
 					   random_access_iterator_tag(), 
 					   random_access_iterator_tag());
 
-	    // Less because shorter.
-	    const bool lbs = mm.first == end1;
-
-	    // Less because differing elements less.
-	    const bool lbdel = pred(*mm.first, *mm.second);
-
-	    return lbs || lbdel;
+	    return (mm.first == end1) || bool(pred(*mm.first, *mm.second));
 	  }
 	else
 	  {
@@ -231,13 +225,7 @@ namespace __parallel
 					   random_access_iterator_tag(), 
 					   random_access_iterator_tag());
 
-	    // Less because shorter.
-	    const bool lbs = mm.first != end2;
-
-	    // Less because differing element less.
-	    const bool lbdel = pred(*mm.second, *mm.first);
-
-	    return lbs && lbdel;
+	    return (mm.first != end2) && bool(pred(*mm.second, *mm.first));
 	  }
       }
     else

libstdc++-v3/testsuite/25_algorithms/sort/34636.cc

+// Copyright (C) 2007 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.
+
+#include <vector>
+#include <algorithm>
+
+// libstdc++/34636
+void test01()
+{
+  std::vector<std::vector<int> > v(2);
+  std::sort(v.begin(), v.end()); 
+}
+
+int main()
+{
+  test01();
+  return 0;
+}