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.

3 files changed, 87 insertions, 1 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 0000000..9021e6e
--- /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();
+}
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/iterators/recursive_directory_iterator.cc b/libstdc++-v3/testsuite/27_io/filesystem/iterators/recursive_directory_iterator.cc
index b0ccdfe..e67e2cf 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/iterators/recursive_directory_iterator.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/iterators/recursive_directory_iterator.cc
@@ -184,6 +184,24 @@ test05()
   remove_all(p, ec);
 }
 
+void
+test06()
+{
+#if !(defined __MINGW32__ || defined __MINGW64__)
+  auto p = __gnu_test::nonexistent_path();
+  create_directories(p/"d1/d2");
+  create_directory_symlink("d1", p/"link");
+  fs::recursive_directory_iterator it(p), endit;
+  VERIFY( std::distance(it, endit) == 3 ); // d1 and d2 and link
+
+  it = fs::recursive_directory_iterator(p, fs::directory_options::follow_directory_symlink);
+  VERIFY( std::distance(it, endit) == 4 ); // d1 and d1/d2 and link and link/d2
+
+  std::error_code ec;
+  remove_all(p, ec);
+#endif
+}
+
 int
 main()
 {
@@ -192,4 +210,5 @@ main()
   test03();
   test04();
   test05();
+  test06();
 }
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc b/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc
index 455dbf2..a201415 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc
@@ -174,7 +174,7 @@ test05()
 {
   auto p = __gnu_test::nonexistent_path();
   create_directory(p);
-  create_directory_symlink(p, p / "l");
+  create_directory(p / "x");
   fs::recursive_directory_iterator it(p), endit;
   VERIFY( begin(it) == it );
   static_assert( noexcept(begin(it)), "begin is noexcept" );
@@ -185,6 +185,24 @@ test05()
   remove_all(p, ec);
 }
 
+void
+test06()
+{
+#if !(defined __MINGW32__ || defined __MINGW64__)
+  auto p = __gnu_test::nonexistent_path();
+  create_directories(p/"d1/d2");
+  create_directory_symlink("d1", p/"link");
+  fs::recursive_directory_iterator it(p), endit;
+  VERIFY( std::distance(it, endit) == 3 ); // d1 and d2 and link
+
+  it = fs::recursive_directory_iterator(p, fs::directory_options::follow_directory_symlink);
+  VERIFY( std::distance(it, endit) == 4 ); // d1 and d1/d2 and link and link/d2
+
+  std::error_code ec;
+  remove_all(p, ec);
+#endif
+}
+
 int
 main()
 {
@@ -193,4 +211,5 @@ main()
   test03();
   test04();
   test05();
+  test06();
 }