PR libstdc++/86597 directory_entry observers should clear error_code

PR libstdc++/86597
	* include/bits/fs_dir.h (directory_entry::_M_file_type(error_code&)):
	Clear error_code when cached type is used.
	* testsuite/27_io/filesystem/directory_entry/86597.cc: New test.

From-SVN: r263397

libstdc++-v3/ChangeLog

@@ -1,3 +1,10 @@
+2018-08-08  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/86597
+	* include/bits/fs_dir.h (directory_entry::_M_file_type(error_code&)):
+	Clear error_code when cached type is used.
+	* testsuite/27_io/filesystem/directory_entry/86597.cc: New test.
+
 2018-08-07  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/86874

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

@@ -318,7 +318,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
     _M_file_type(error_code& __ec) const noexcept
     {
       if (_M_type != file_type::none && _M_type != file_type::symlink)
-	return _M_type;
+	{
+	  __ec.clear();
+	  return _M_type;
+	}
       return status(__ec).type();
     }
 

libstdc++-v3/testsuite/27_io/filesystem/directory_entry/86597.cc

@@ -0,0 +1,74 @@
+// Copyright (C) 2018 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++17 -lstdc++fs" }
+// { dg-do run { target c++17 } }
+// { dg-require-filesystem-ts "" }
+
+#include <filesystem>
+#include <system_error>
+#include <testsuite_hooks.h>
+#include <testsuite_fs.h>
+
+// PR libstdc++/86597
+
+void
+test01()
+{
+  const auto bad_ec = make_error_code(std::errc::address_in_use);
+  std::error_code ec;
+  std::filesystem::directory_entry ent(".");
+
+  ec = bad_ec;
+  VERIFY( ent.exists(ec) );
+  VERIFY( !ec );
+
+  ec = bad_ec;
+  VERIFY( ent.is_directory(ec) );
+  VERIFY( !ec );
+
+  ec = bad_ec;
+  VERIFY( !ent.is_regular_file(ec) );
+  VERIFY( !ec );
+}
+
+void
+test02()
+{
+  const auto bad_ec = make_error_code(std::errc::address_in_use);
+  std::error_code ec;
+  std::filesystem::directory_entry ent(__gnu_test::nonexistent_path());
+
+  ec = bad_ec;
+  VERIFY( !ent.exists(ec) );
+  VERIFY( !ec );
+
+  ec = bad_ec;
+  VERIFY( !ent.is_directory(ec) );
+  VERIFY( !ec );
+
+  ec = bad_ec;
+  VERIFY( !ent.is_regular_file(ec) );
+  VERIFY( !ec );
+}
+
+int
+main()
+{
+  test01();
+  test02();
+}