--- /dev/null
+//===----------------------------------------------------------------------===//
+//
+// 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;
+}