re PR libstdc++/64646 (New overloads of std::is_permutation dereference past-the-end iterator)

	PR libstdc++/64646
	* include/bits/stl_algo.h (__is_permutation): Also test for reaching
	end of the second range.
	* testsuite/25_algorithms/is_permutation/64646.cc: New.

From-SVN: r219821

libstdc++-v3/ChangeLog

 2015-01-18  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/64646
+	* include/bits/stl_algo.h (__is_permutation): Also test for reaching
+	end of the second range.
+	* testsuite/25_algorithms/is_permutation/64646.cc: New.
+
+2015-01-18  Jonathan Wakely  <jwakely@redhat.com>
+
 	* doc/xml/manual/status_cxx2011.xml: Remove note about offsetof.
 	* doc/html/manual/status.html: Regenerate.
 

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

@@ -3601,7 +3601,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       // Efficiently compare identical prefixes:  O(N) if sequences
       // have the same elements in the same order.
-      for (; __first1 != __last1; ++__first1, ++__first2)
+      for (; __first1 != __last1 && __first2 != __last2;
+	  ++__first1, ++__first2)
 	if (!__pred(__first1, __first2))
 	  break;
 

libstdc++-v3/testsuite/25_algorithms/is_permutation/64646.cc

+// Copyright (C) 2015 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 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++14" }
+
+#include <algorithm>
+#include <forward_list>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  std::forward_list<int> l1{0}, l2;
+  VERIFY( !std::is_permutation(l1.begin(), l1.end(), l2.begin(), l2.end()) );
+}
+
+int
+main()
+{
+  test01();
+}