[PATCH] Fix std::wbuffer_convert::sync()

[Jonathan Wakely]

My recent fix to wbuffer_convert::_M_put isn't the only problem in
that class, I also messed up the condition in wbuffer_convert::sync.

        * include/bits/locale_conv.h (wbuffer_convert::sync): Fix condition.
        * testsuite/22_locale/conversions/buffer/2.cc: New.

Tested powerpc64le-linux, committed to trunk.

I'm also testing this for the branches and will fix it there too.


commit 02d02f35ce5c96136edf8bb8ec8035b236303079
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Fri Jun 16 13:59:43 2017 +0100

    Fix std::wbuffer_convert::sync()
    
        * include/bits/locale_conv.h (wbuffer_convert::sync): Fix condition.
        * testsuite/22_locale/conversions/buffer/2.cc: New.

diff --git a/libstdc++-v3/include/bits/locale_conv.h 
b/libstdc++-v3/include/bits/locale_conv.h
index 74beaec..47c8dee 100644
--- a/libstdc++-v3/include/bits/locale_conv.h
+++ b/libstdc++-v3/include/bits/locale_conv.h
@@ -375,7 +375,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     protected:
       int
       sync()
-      { return _M_buf && _M_conv_put() && _M_buf->pubsync() ? 0 : -1; }
+      { return _M_buf && _M_conv_put() && !_M_buf->pubsync() ? 0 : -1; }
 
       typename _Wide_streambuf::int_type
       overflow(typename _Wide_streambuf::int_type __out)
diff --git a/libstdc++-v3/testsuite/22_locale/conversions/buffer/2.cc 
b/libstdc++-v3/testsuite/22_locale/conversions/buffer/2.cc
new file mode 100644
index 0000000..8eda714
--- /dev/null
+++ b/libstdc++-v3/testsuite/22_locale/conversions/buffer/2.cc
@@ -0,0 +1,39 @@
+// Copyright (C) 2017 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-do run { target c++11 } }
+
+#include <locale>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  struct Cvt : std::codecvt<char, char, std::mbstate_t> { };
+  std::stringstream ss;
+  std::wbuffer_convert<Cvt, char> cvt(ss.rdbuf());
+  auto p = ss.std::ios::rdbuf(&cvt);
+  ss << "hello";
+  VERIFY( ss.flush().good() );
+  ss.std::ios::rdbuf(p);
+}
+
+int main()
+{
+  test01();
+}