1 files changed, 56 insertions, 0 deletions
diff --git a/libcxx/test/std/input.output/file.streams/fstreams/filebuf.members/close.pass.cpp b/libcxx/test/std/input.output/file.streams/fstreams/filebuf.members/close.pass.cpp
new file mode 100644
index 00000000000..b545041e428
--- /dev/null
+++ b/libcxx/test/std/input.output/file.streams/fstreams/filebuf.members/close.pass.cpp
@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <fstream>
+
+// basic_filebuf<charT,traits>* close();
+
+#include <fstream>
+#include <cassert>
+#if defined(__unix__)
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+#include "test_macros.h"
+#include "platform_support.h"
+
+int main(int, char**)
+{
+    std::string temp = get_temp_file_name();
+    {
+        std::filebuf f;
+        assert(!f.is_open());
+        assert(f.open(temp.c_str(), std::ios_base::out) != 0);
+        assert(f.is_open());
+        assert(f.close() != nullptr);
+        assert(!f.is_open());
+        assert(f.close() == nullptr);
+        assert(!f.is_open());
+    }
+#if defined(__unix__)
+    {
+        std::filebuf f;
+        assert(!f.is_open());
+        // Use open directly to get the file descriptor.
+        int fd = open(temp.c_str(), O_RDWR);
+        assert(fd >= 0);
+        // Use the internal method to create filebuf from the file descriptor.
+        assert(f.__open(fd, std::ios_base::out) != 0);
+        assert(f.is_open());
+        // Close the file descriptor directly to force filebuf::close to fail.
+        assert(close(fd) == 0);
+        // Ensure that filebuf::close handles the failure.
+        assert(f.close() == nullptr);
+        assert(!f.is_open());
+        assert(f.close() == nullptr);
+    }
+#endif
+    std::remove(temp.c_str());
+
+    return 0;
+}