diff mbox series

[v2] Add more thorough tests of freopen

Message ID c316478-cf32-94fd-7b52-b2cf2ae1924@redhat.com
State New
Headers show
Series [v2] Add more thorough tests of freopen | expand

Commit Message

Joseph Myers Sept. 2, 2024, 10:03 p.m. UTC 
On Mon, 2 Sep 2024, Florian Weimer wrote:

> I think it's clear that it's possible to use freopen on streams created
> by fopen (where it is somewhat redundant for us) and on the (in glibc's
> case initial) values of stdin, stdout, stderr, where it is essential for
> non-POSIX platforms.  But there are other ways to create streams.  It
> seems to be the interaction with popen, fmemopen, open_memstream, and
> glibc's fopencookie has been ignored so far.
> 
> Some of these combinations do not work at all in the glibc
> implementation, something that cannot be fixed easily, so I think we
> should document these limitations in the glibc manual.  This seems to be
> unaddressed in the POSIX text.

I propose to add documentation, and tests for stdin / stdout / stderr, 
separately.  This revised patch does test the case of a stream opened with 
fopen64, and that of reopening a stream more than once (including mixing 
freopen and freopen64).

> You could add mtrace and <support/descriptors.h> checks around all the
> tests to verify that there are now leaks, as in this test:

<support/descriptors.h> tests added.  mtrace tests run into existing 
leaks, I think bug 24583 - should I split out the ,ccs= tests so the rest 
can have mtrace tests?

> A separate test (using support_become_root, support_can_chroot) could
> check what happens if /proc is not mounted and the /proc/self/fd code
> path is used.

I propose to add that separately as well.

> > +  verbose_printf ("Testing r -> r\n");
> > +  fp = xfopen (file1, "r");
> > +  fp = freopen (file2, "r", fp);
> > +  TEST_VERIFY_EXIT (fp != NULL);
> > +  TEST_COMPARE_FILE_STRING (fp, "file2");
> > +  xfclose (fp);
> 
> As a general comment, I would have expected a check that the
> non-modified file is in fact not modified.  Seems very likely given our
> implementation, but still.  (I wonder if it would be conforming to
> create a hard link to the new name on freopen.)

Added such a check (not for this specific r -> r test).

> > +  /* Test freopen with NULL, renamed file.  */
> 
> This is supposed to exercise the /proc/self/fd path and show that no new
> pathname lookup is peformed, right?  (Along with the following test.)  A
> comment could mention that.

I've expanded the comment (not specifically referencing /proc/self/fd 
since I'm thinking of this as testing the feature rather than the 
implementation approach).



Add more thorough tests of freopen

freopen is rather minimally tested in libio/tst-freopen and
libio/test-freopen.  Add some more thorough tests, covering different
cases for change of mode in particular.  The tests are run for both
freopen and freopen64 (given that those functions have two separate
copies of much of the code, so any bug fix directly in the freopen
code would probably need applying in both places).

Note that there are two parts of the test disabled because of bugs
discovered through running the test, with bug numbers given in
comments.  I expect to address those separately.  The test also
doesn't cover changes to cancellation ("c" in mode); I think that will
better be handled through a separate test.  Also to handle separately:
testing on stdin / stdout / stderr; documenting lack of support for
streams opened with popen / fmemopen / open_memstream / fopencookie;
maybe also a chroot test without /proc; maybe also more thorough tests
for large file handling on 32-bit systems (freopen64).

Tested for x86_64.

---

Changed in v2: the support/ changes (on which this depends) have been
sent as a separate patch; test both freopen and freopen64; use
support/descriptors.h to check for descriptor leaks; make a -> a test
really test a -> a not w -> a; also test files opened with fopen64;
also test calling freopen more than once on the same FILE * (or mixing
freopen and freopen64); check unmodified file contents in some cases;
expand comments on tests with renamed or deleted files.

Comments

Florian Weimer Sept. 3, 2024, 10:39 a.m. UTC | #1 
* Joseph Myers:

> On Mon, 2 Sep 2024, Florian Weimer wrote:
>
>> I think it's clear that it's possible to use freopen on streams created
>> by fopen (where it is somewhat redundant for us) and on the (in glibc's
>> case initial) values of stdin, stdout, stderr, where it is essential for
>> non-POSIX platforms.  But there are other ways to create streams.  It
>> seems to be the interaction with popen, fmemopen, open_memstream, and
>> glibc's fopencookie has been ignored so far.
>> 
>> Some of these combinations do not work at all in the glibc
>> implementation, something that cannot be fixed easily, so I think we
>> should document these limitations in the glibc manual.  This seems to be
>> unaddressed in the POSIX text.
>
> I propose to add documentation, and tests for stdin / stdout / stderr, 
> separately.  This revised patch does test the case of a stream opened with 
> fopen64, and that of reopening a stream more than once (including mixing 
> freopen and freopen64).

Makes sense.

>> You could add mtrace and <support/descriptors.h> checks around all the
>> tests to verify that there are now leaks, as in this test:
>
> <support/descriptors.h> tests added.  mtrace tests run into existing 
> leaks, I think bug 24583 - should I split out the ,ccs= tests so the rest 
> can have mtrace tests?

Yes please, if it's not too much trouble.

>> A separate test (using support_become_root, support_can_chroot) could
>> check what happens if /proc is not mounted and the /proc/self/fd code
>> path is used.
>
> I propose to add that separately as well.

Okay.

The additions so far look good to mee.  I think after the ,ccs= split
and the mtrace addition, this can go in.

Thanks,
Florian
diff mbox series

Patch

diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index 948d960ccc..49258a26f3 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -216,6 +216,8 @@  tests := \
   tst-fmemopen4 \
   tst-fphex \
   tst-fphex-wide \
+  tst-freopen2 \
+  tst-freopen64-2 \
   tst-fseek \
   tst-fwrite \
   tst-getline \
diff --git a/stdio-common/tst-freopen2-main.c b/stdio-common/tst-freopen2-main.c
new file mode 100644
index 0000000000..76a56e344d
--- /dev/null
+++ b/stdio-common/tst-freopen2-main.c
@@ -0,0 +1,547 @@ 
+/* Test freopen.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+
+#include <support/check.h>
+#include <support/descriptors.h>
+#include <support/file_contents.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <support/test-driver.h>
+#include <support/xstdio.h>
+
+#define START_TEST(DESC)			\
+  do						\
+    {						\
+      fds = support_descriptors_list ();	\
+      verbose_printf (DESC);			\
+    }						\
+  while (0)
+
+#define END_TEST				\
+  do						\
+    {						\
+      support_descriptors_check (fds);		\
+      support_descriptors_free (fds);		\
+    }						\
+  while (0)
+
+int
+do_test (void)
+{
+  struct support_descriptors *fds;
+  char *temp_dir = support_create_temp_directory ("tst-freopen2");
+  char *file1 = xasprintf ("%s/file1", temp_dir);
+  support_write_file_string (file1, "file1");
+  add_temp_file (file1);
+  char *file2 = xasprintf ("%s/file2", temp_dir);
+  support_write_file_string (file2, "file2");
+  add_temp_file (file2);
+  char *file3 = xasprintf ("%s/file3", temp_dir);
+  char *file4 = xasprintf ("%s/file4", temp_dir);
+  char *file_nodir = xasprintf ("%s/nodir/file", temp_dir);
+  char *file1a = xasprintf ("%s/file1a", temp_dir);
+  FILE *fp;
+  int ret;
+  wint_t wc;
+  int fd;
+
+  /* Test each pair of old and new modes from r w a.  */
+
+  START_TEST ("Testing r -> r\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "file2");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("Testing r -> w\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("File2new", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file1, "file1");
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "File2new");
+  END_TEST;
+
+  START_TEST ("Testing r -> a\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "a", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("3", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "File2new3");
+  END_TEST;
+
+  START_TEST ("Testing w -> r\n");
+  fp = xfopen (file1, "w");
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "File2new3");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("Testing w -> w\n");
+  fp = xfopen (file1, "w");
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("next", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file1, "");
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "next");
+  END_TEST;
+
+  START_TEST ("Testing w -> a\n");
+  fp = xfopen (file1, "w");
+  fp = FREOPEN (file2, "a", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("4", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "next4");
+  END_TEST;
+
+  START_TEST ("Testing a -> r\n");
+  fp = xfopen (file1, "a");
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "next4");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("Testing a -> w\n");
+  fp = xfopen (file1, "a");
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("another", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "another");
+  END_TEST;
+
+  START_TEST ("Testing a -> a\n");
+  fp = xfopen (file1, "a");
+  fp = FREOPEN (file2, "a", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("5", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "another5");
+  END_TEST;
+
+  /* Test for file originally opened with fopen64.  */
+  START_TEST ("Testing fopen64 a -> a\n");
+  fp = fopen64 (file1, "a");
+  TEST_VERIFY_EXIT (fp != NULL);
+  fp = FREOPEN (file2, "a", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("64", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "another564");
+  END_TEST;
+
+  /* Test calling freopen more than once on the same FILE *.  */
+
+  START_TEST ("Testing r -> w -> r\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("freopen-twice", fp);
+  TEST_VERIFY (ret >= 0);
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "freopen-twice");
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "freopen-twice");
+  END_TEST;
+
+  START_TEST ("Testing r -> w -> r (exactly one freopen64)\n");
+  fp = xfopen (file1, "r");
+  fp = OTHER_FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("freopen-twice64", fp);
+  TEST_VERIFY (ret >= 0);
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "freopen-twice64");
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "freopen-twice64");
+  END_TEST;
+
+  /* Test changing to/from b (binary, no-op).  */
+
+  START_TEST ("Testing rb -> r\n");
+  fp = xfopen (file1, "rb");
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "freopen-twice64");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("Testing r -> rb\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "rb", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "freopen-twice64");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test changing to/from + (read-and-write).  */
+
+  START_TEST ("Testing r -> w+\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "w+", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("latest", fp);
+  TEST_VERIFY (ret >= 0);
+  ret = fseek (fp, 0, SEEK_SET);
+  TEST_COMPARE (ret, 0);
+  TEST_COMPARE_FILE_STRING (fp, "latest");
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "latest");
+  END_TEST;
+
+  START_TEST ("Testing w -> a+\n");
+  fp = xfopen (file1, "w");
+  fp = FREOPEN (file2, "a+", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("suffix", fp);
+  TEST_VERIFY (ret >= 0);
+  ret = fseek (fp, 0, SEEK_SET);
+  TEST_COMPARE (ret, 0);
+  TEST_COMPARE_FILE_STRING (fp, "latestsuffix");
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "latestsuffix");
+  END_TEST;
+
+  START_TEST ("Testing a -> r+\n");
+  fp = xfopen (file1, "a");
+  fp = FREOPEN (file2, "r+", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "latestsuffix");
+  ret = fseek (fp, 0, SEEK_SET);
+  TEST_COMPARE (ret, 0);
+  ret = fputs ("new", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "newestsuffix");
+  END_TEST;
+
+  START_TEST ("Testing r+ -> w\n");
+  fp = xfopen (file1, "r+");
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("plusto", fp);
+  TEST_VERIFY (ret >= 0);
+  ret = fseek (fp, 0, SEEK_SET);
+  TEST_COMPARE (ret, 0);
+  errno = 0;
+  TEST_COMPARE (fgetc (fp), EOF);
+  TEST_COMPARE (errno, EBADF);
+  clearerr (fp);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "plusto");
+  END_TEST;
+
+  START_TEST ("Testing w+ -> a\n");
+  fp = xfopen (file1, "w+");
+  fp = FREOPEN (file2, "a", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("more", fp);
+  TEST_VERIFY (ret >= 0);
+  ret = fseek (fp, 0, SEEK_SET);
+  TEST_COMPARE (ret, 0);
+  errno = 0;
+  TEST_COMPARE (fgetc (fp), EOF);
+  TEST_COMPARE (errno, EBADF);
+  clearerr (fp);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "plustomore");
+  END_TEST;
+
+  START_TEST ("Testing a+ -> r\n");
+  fp = xfopen (file1, "a+");
+  fp = FREOPEN (file2, "rr", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "plustomore");
+  ret = fputs ("2", fp);
+  TEST_COMPARE (ret, EOF);
+  clearerr (fp);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "plustomore");
+  END_TEST;
+
+  /* Test changing to/from e (FD_CLOEXEC).  */
+
+  START_TEST ("Testing re -> r\n");
+  fp = xfopen (file1, "re");
+  ret = fcntl (fileno (fp), F_GETFD);
+  TEST_VERIFY (ret != -1);
+  TEST_COMPARE (ret & FD_CLOEXEC, FD_CLOEXEC);
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fcntl (fileno (fp), F_GETFD);
+  TEST_VERIFY (ret != -1);
+#if 0 /* Fails to clear FD_CLOEXEC (bug 32134).  */
+  TEST_COMPARE (ret & FD_CLOEXEC, 0);
+#endif
+  TEST_COMPARE_FILE_STRING (fp, "plustomore");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("Testing r -> re\n");
+  fp = xfopen (file1, "r");
+  ret = fcntl (fileno (fp), F_GETFD);
+  TEST_VERIFY (ret != -1);
+  TEST_COMPARE (ret & FD_CLOEXEC, 0);
+  fp = FREOPEN (file2, "re", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fcntl (fileno (fp), F_GETFD);
+  TEST_VERIFY (ret != -1);
+  TEST_COMPARE (ret & FD_CLOEXEC, FD_CLOEXEC);
+  TEST_COMPARE_FILE_STRING (fp, "plustomore");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test changing to/from m (mmap) (a no-op as far as testing
+     semantics is concerned).  */
+
+  START_TEST ("Testing rm -> r\n");
+  fp = xfopen (file1, "rm");
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "plustomore");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("Testing r -> rm\n");
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (file2, "rm", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "plustomore");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test changing to/from x (O_EXCL).  */
+
+  START_TEST ("Testing wx -> w\n");
+  fp = xfopen (file3, "wx");
+  add_temp_file (file3);
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = fputs ("wxtow", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file2, "wxtow");
+  END_TEST;
+
+  START_TEST ("Testing w -> wx (file does not exist)\n");
+  fp = xfopen (file1, "w");
+  fp = FREOPEN (file4, "wx", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  add_temp_file (file4);
+  ret = fputs ("wtowx", fp);
+  TEST_VERIFY (ret >= 0);
+  xfclose (fp);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file4, "wtowx");
+  END_TEST;
+
+  START_TEST ("Testing w -> wx (file exists)\n");
+  fp = xfopen (file1, "w");
+  fp = FREOPEN (file4, "wx", fp);
+  TEST_VERIFY (fp == NULL);
+  END_TEST;
+
+  /* Test with ,ccs=CHARSET.  */
+
+  START_TEST ("testing w,ccs=utf-8 -> r\n");
+  fp = xfopen (file1, "w,ccs=utf-8");
+  ret = fputws (L"\xc0\xc1", fp);
+  TEST_VERIFY (ret >= 0);
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "wxtow");
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("testing w,ccs=iso-8859-1 -> r,ccs=utf-8\n");
+  fp = xfopen (file2, "w,ccs=iso-8859-1");
+  ret = fputws (L"\xc0\xc1", fp);
+  TEST_VERIFY (ret >= 0);
+#if 0 /* Doesn't work (bug 23675).  */
+  fp = FREOPEN (file1, "r,ccs=utf-8", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+#else /* Works instead.  */
+  xfclose (fp);
+  fp = xfopen (file1, "r,ccs=utf-8");
+#endif
+  wc = fgetwc (fp);
+  TEST_COMPARE (wc, (wint_t) 0xc0);
+  wc = fgetwc (fp);
+  TEST_COMPARE (wc, (wint_t) 0xc1);
+  wc = fgetwc (fp);
+  TEST_COMPARE (wc, WEOF);
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("testing r,ccs=utf-8 -> r\n");
+  fp = xfopen (file1, "r,ccs=utf-8");
+  fp = FREOPEN (file1, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "\u00c0\u00c1");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test old file is closed even when opening the new file fails.  */
+
+  START_TEST ("testing r -> r (opening new file fails)\n");
+  fp = xfopen (file1, "r");
+  fd = fileno (fp);
+  fp = FREOPEN (file_nodir, "r", fp);
+  TEST_VERIFY (fp == NULL);
+  errno = 0;
+  ret = fcntl (fd, F_GETFL);
+  TEST_COMPARE (ret, -1);
+  TEST_COMPARE (errno, EBADF);
+  END_TEST;
+
+  /* Test that errors closing the old file are ignored.  */
+
+  START_TEST ("testing errors closing old file ignored\n");
+  fp = xfopen ("/dev/full", "w");
+  fputc ('x', fp);
+  fp = FREOPEN (file1, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "\u00c0\u00c1");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test that error / EOF state from the old file are cleared.  */
+
+  START_TEST ("testing error state from old file cleared\n");
+  fp = xfopen ("/dev/full", "w");
+  fputc ('x', fp);
+  fflush (fp);
+  TEST_VERIFY (ferror (fp));
+  TEST_VERIFY (!feof (fp));
+  fp = FREOPEN (file2, "w", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_VERIFY (!ferror (fp));
+  TEST_VERIFY (!feof (fp));
+  xfclose (fp);
+  END_TEST;
+
+  START_TEST ("testing EOF state from old file cleared\n");
+  fp = xfopen ("/dev/null", "r");
+  fgetc (fp);
+  TEST_VERIFY (!ferror (fp));
+  TEST_VERIFY (feof (fp));
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_VERIFY (!ferror (fp));
+  TEST_VERIFY (!feof (fp));
+  xfclose (fp);
+  END_TEST;
+
+  /* Test freopen with NULL, same mode (should flush content and reset
+     file offset).  */
+
+  START_TEST ("testing freopen with NULL, same mode\n");
+  fp = xfopen (file1, "r+");
+  ret = fputs ("same mode", fp);
+  TEST_VERIFY (ret >= 0);
+  fp = FREOPEN (NULL, "r+", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "same mode");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test freopen with NULL, different mode.  */
+
+  START_TEST ("testing freopen with NULL, different mode\n");
+  fp = xfopen (file1, "w");
+  ret = fputs ("different mode", fp);
+  TEST_VERIFY (ret >= 0);
+  fp = FREOPEN (NULL, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "different mode");
+  xfclose (fp);
+  END_TEST;
+
+  /* Test freopen with NULL, renamed file.  This verifies that
+     reopening succeeds (and resets the file position indicator to
+     start of file) even when the original path could no longer be
+     opened.  */
+
+  START_TEST ("testing freopen with NULL, renamed file\n");
+  fp = xfopen (file1, "r+");
+  ret = fputs ("file has been renamed", fp);
+  TEST_VERIFY (ret >= 0);
+  ret = rename (file1, file1a);
+  TEST_COMPARE (ret, 0);
+  fp = FREOPEN (NULL, "r+", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "file has been renamed");
+  xfclose (fp);
+  ret = rename (file1a, file1);
+  TEST_COMPARE (ret, 0);
+  END_TEST;
+
+  /* Test freopen with NULL, deleted file.  This verifies that
+     reopening succeeds (and resets the file position indicator to
+     start of file) even when the original path could no longer be
+     opened.  */
+
+  START_TEST ("testing freopen with NULL, deleted file\n");
+  fp = xfopen (file1, "r+");
+  ret = fputs ("file has now been deleted", fp);
+  TEST_VERIFY (ret >= 0);
+  ret = remove (file1);
+  TEST_COMPARE (ret, 0);
+  fp = FREOPEN (NULL, "r+", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  TEST_COMPARE_FILE_STRING (fp, "file has now been deleted");
+  xfclose (fp);
+  /* Recreate the file so it is present when expected for temporary
+     file deletion.  */
+  support_write_file_string (file1, "file1");
+  END_TEST;
+
+  free (temp_dir);
+  free (file1);
+  free (file2);
+  free (file3);
+  free (file4);
+  free (file_nodir);
+  free (file1a);
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/stdio-common/tst-freopen2.c b/stdio-common/tst-freopen2.c
new file mode 100644
index 0000000000..11ec7a9783
--- /dev/null
+++ b/stdio-common/tst-freopen2.c
@@ -0,0 +1,3 @@ 
+#define FREOPEN freopen
+#define OTHER_FREOPEN freopen64
+#include <tst-freopen2-main.c>
diff --git a/stdio-common/tst-freopen64-2.c b/stdio-common/tst-freopen64-2.c
new file mode 100644
index 0000000000..88fdc64d8c
--- /dev/null
+++ b/stdio-common/tst-freopen64-2.c
@@ -0,0 +1,3 @@ 
+#define FREOPEN freopen64
+#define OTHER_FREOPEN freopen
+#include <tst-freopen2-main.c>