diff options
Diffstat (limited to 'stdio-common/tst-fclose-offset.c')
| -rw-r--r-- | stdio-common/tst-fclose-offset.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/stdio-common/tst-fclose-offset.c b/stdio-common/tst-fclose-offset.c new file mode 100644 index 0000000..a31de11 --- /dev/null +++ b/stdio-common/tst-fclose-offset.c @@ -0,0 +1,225 @@ +/* Test offset of input file descriptor after close (bug 12724). + Copyright (C) 2025 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 <stdio.h> +#include <wchar.h> + +#include <support/check.h> +#include <support/temp_file.h> +#include <support/xstdio.h> +#include <support/xunistd.h> + +int +do_test (void) +{ + char *filename = NULL; + int fd = create_temp_file ("tst-fclose-offset", &filename); + TEST_VERIFY_EXIT (fd != -1); + + /* Test offset of open file description for output and input streams + after fclose, case from bug 12724. */ + + const char buf[] = "hello world"; + xwrite (fd, buf, sizeof buf); + TEST_COMPARE (lseek (fd, 1, SEEK_SET), 1); + int fd2 = xdup (fd); + FILE *f = fdopen (fd2, "w"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fputc (buf[1], f), buf[1]); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 2); + + /* Likewise for an input stream. */ + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fgetc (f), buf[2]); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 3); + + /* Test offset of open file description for output and input streams + after fclose, case from comment on bug 12724 (failed after first + attempt at fixing that bug). This verifies that the offset is + not reset when there has been no input or output on the FILE* (in + that case, the FILE* might not be the active handle). */ + + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + xwrite (fd, buf, sizeof buf); + TEST_COMPARE (lseek (fd, 1, SEEK_SET), 1); + fd2 = xdup (fd); + f = fdopen (fd2, "w"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Likewise for an input stream. */ + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Further cases without specific tests in bug 12724, to verify + proper operation of the rules about the offset only being set + when the stream is the active handle. */ + + /* Test offset set by fclose after fseek and fgetc. */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fseek (f, 1, SEEK_SET), 0); + TEST_COMPARE (fgetc (f), buf[1]); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 2); + + /* Test offset not set by fclose after fseek and fgetc, if that + fgetc is at EOF (in which case the active handle might have + changed). */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fseek (f, sizeof buf, SEEK_SET), 0); + TEST_COMPARE (fgetc (f), EOF); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Test offset not set by fclose after fseek and fgetc and fflush + (active handle might have changed after fflush). */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fseek (f, 1, SEEK_SET), 0); + TEST_COMPARE (fgetc (f), buf[1]); + TEST_COMPARE (fflush (f), 0); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Test offset not set by fclose after fseek and fgetc, if the + stream is unbuffered (active handle might change at any + time). */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + setbuf (f, NULL); + TEST_COMPARE (fseek (f, 1, SEEK_SET), 0); + TEST_COMPARE (fgetc (f), buf[1]); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Also test such cases with the stream in wide mode. */ + + /* Test offset set by fclose after fseek and fgetwc. */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fseek (f, 1, SEEK_SET), 0); + TEST_COMPARE (fgetwc (f), (wint_t) buf[1]); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 2); + + /* Test offset not set by fclose after fseek and fgetwc, if that + fgetwc is at EOF (in which case the active handle might have + changed). */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fseek (f, sizeof buf, SEEK_SET), 0); + TEST_COMPARE (fgetwc (f), WEOF); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Test offset not set by fclose after fseek and fgetwc and fflush + (active handle might have changed after fflush). */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + TEST_COMPARE (fseek (f, 1, SEEK_SET), 0); + TEST_COMPARE (fgetwc (f), (wint_t) buf[1]); + TEST_COMPARE (fflush (f), 0); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + /* Test offset not set by fclose after fseek and fgetwc, if the + stream is unbuffered (active handle might change at any + time). */ + TEST_COMPARE (lseek (fd, 0, SEEK_SET), 0); + fd2 = xdup (fd); + f = fdopen (fd2, "r"); + TEST_VERIFY_EXIT (f != NULL); + setbuf (f, NULL); + TEST_COMPARE (fseek (f, 1, SEEK_SET), 0); + TEST_COMPARE (fgetwc (f), (wint_t) buf[1]); + TEST_COMPARE (lseek (fd, 4, SEEK_SET), 4); + xfclose (f); + errno = 0; + TEST_COMPARE (lseek (fd2, 0, SEEK_CUR), -1); + TEST_COMPARE (errno, EBADF); + TEST_COMPARE (lseek (fd, 0, SEEK_CUR), 4); + + return 0; +} + +#include <support/test-driver.c> |