Fix PR52822 (stable_partition move-assigns object to itself) by scanning for...

Fix PR52822 (stable_partition move-assigns object to itself) by
scanning for the first value that doesn't match the predicate before
starting to rearrange values.

2012-04-03   Jeffrey Yasskin  <jyasskin@google.com>

	PR libstdc++/52822
	* include/bits/stl_algo.h (__find_if_not): Expose in
	C++98 mode.
	(__find_if_not_n): Like __find_if_not, but works on and updates a
	counted range instead of a bounded range.
	(stable_partition): Guarantee !__pred(*__first) in call to
	__stable_partition_adaptive() or __inplace_stable_partition().
	(__stable_partition_adaptive): Use new precondition to avoid
	moving/copying objects onto themselves.  Guarantee new
	precondition to recursive calls.
	(__inplace_stable_partition): Use new precondition to simplify
	base case, remove __last parameter.  Guarantee new precondition to
	recursive calls.
	* testsuite/25_algorithms/stable_partition/moveable.cc (test02):
	Test a sequence that starts with a value matching the predicate.
	* testsuite/25_algorithms/stable_partition/pr52822.cc:
	Test vectors, which have a destructive self-move-assignment.

From-SVN: r186391

2 files changed, 64 insertions, 1 deletions

diff --git a/libstdc++-v3/testsuite/25_algorithms/stable_partition/moveable.cc b/libstdc++-v3/testsuite/25_algorithms/stable_partition/moveable.cc
index b649b10..95d5006 100644
--- a/libstdc++-v3/testsuite/25_algorithms/stable_partition/moveable.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/stable_partition/moveable.cc
@@ -35,6 +35,11 @@ const int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17};
 const int B[] = {2, 4, 6, 8, 10, 12, 14, 16, 1, 3, 5, 7, 9, 11, 13, 15, 17};
 const int N = sizeof(A) / sizeof(int);
 
+// Check that starting with a true predicate works too. (PR52822)
+const int A2[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17};
+const int B2[] = {2, 4, 6, 8, 10, 12, 14, 16, 3, 5, 7, 9, 11, 13, 15, 17};
+const int N2 = sizeof(A2) / sizeof(int);
+
 struct Pred
 {
   bool
@@ -42,7 +47,7 @@ struct Pred
   { return (x.val % 2) == 0; }
 };
 
-// 25.2.12 stable_partition()
+// 25.2.12 stable_partition(), starting with a false predicate.
 void
 test01()
 {
@@ -56,9 +61,24 @@ test01()
   VERIFY( std::equal(s1, s1 + N, B) );
 }
 
+// 25.2.12 stable_partition(), starting with a true predicate.
+void
+test02()
+{
+  bool test __attribute__((unused)) = true;
+
+  rvalstruct s1[N2];
+  std::copy(A2, A2 + N2, s1);
+  Container con(s1, s1 + N2);
+
+  std::stable_partition(con.begin(), con.end(), Pred());
+  VERIFY( std::equal(s1, s1 + N2, B2) );
+}
+
 int
 main()
 {
   test01();
+  test02();
   return 0;
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/stable_partition/pr52822.cc b/libstdc++-v3/testsuite/25_algorithms/stable_partition/pr52822.cc
new file mode 100644
index 0000000..c5f95f3
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/stable_partition/pr52822.cc
@@ -0,0 +1,43 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 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
+// 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 Pred 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/>.
+
+// 25.2.12 [lib.alg.partitions] Partitions.
+
+#include <algorithm>
+#include <vector>
+#include <testsuite_hooks.h>
+
+bool true_vector_pred(const std::vector<int>&) { return true; }
+
+void
+test01()
+{
+  std::vector<std::vector<int> > v(1);
+  v[0].push_back(7);
+  VERIFY( v[0].size() == 1 );
+  std::stable_partition(v.begin(), v.end(), &true_vector_pred);
+  VERIFY( v[0].size() == 1 );
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}