libstdc++: Add more tests for filesystem directory iterators

The PR 97731 test was added to verify a fix to the Filesystem TS code,
but we should also have the same test to avoid similar regressions in
the C++17 std::filesystem code.

Also add tests for directory_options::follow_directory_symlink

libstdc++-v3/ChangeLog:

	* testsuite/27_io/filesystem/iterators/97731.cc: New test.
	* testsuite/27_io/filesystem/iterators/recursive_directory_iterator.cc:
	Check follow_directory_symlink option.
	* testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc:
	Likewise.

1 files changed, 48 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/27_io/filesystem/iterators/97731.cc b/libstdc++-v3/testsuite/27_io/filesystem/iterators/97731.cc
new file mode 100644
index 00000000000..9021e6edf41
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/filesystem/iterators/97731.cc
@@ -0,0 +1,48 @@
+// Copyright (C) 2020-2022 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++17 } }
+// { dg-require-filesystem-ts "" }
+
+#include <filesystem>
+#include <cerrno>
+#include <testsuite_hooks.h>
+
+bool used_custom_readdir = false;
+
+extern "C" void* readdir(void*)
+{
+  used_custom_readdir = true;
+  errno = EIO;
+  return nullptr;
+}
+
+void
+test01()
+{
+  using std::filesystem::recursive_directory_iterator;
+  std::error_code ec;
+  recursive_directory_iterator it(".", ec);
+  if (used_custom_readdir)
+    VERIFY( ec.value() == EIO );
+}
+
+int
+main()
+{
+  test01();
+}