From: Ulrich Drepper Date: Sat, 14 May 2011 01:08:45 +0000 (+0100) Subject: Fix file descriptor position after fclose X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82c938203add9de265744987c8f1efa454d80461;p=thirdparty%2Fglibc.git Fix file descriptor position after fclose fclose should leave the file descriptor position after the last read or written byte. (cherry picked from commit fcabc0f8b185f9e0a9289720be5ede6c39b3bf21) --- diff --git a/ChangeLog b/ChangeLog index 50772691bc3..221f8a91188 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2011-05-13 Ulrich Drepper + + [BZ #12724] + * libio/fileops.c (_IO_new_file_close_it): Always flush when + currently writing and seek to current position when not. + * libio/Makefile (tests): Add bug-fclose1. + * libio/bug-fclose1.c: New file. + 2011-05-12 Ulrich Drepper [BZ #12511] diff --git a/libio/Makefile b/libio/Makefile index 83b9458dc2b..ec309048411 100644 --- a/libio/Makefile +++ b/libio/Makefile @@ -1,4 +1,4 @@ -# Copyright (C) 1995-2004,2006,2007,2008,2009 Free Software Foundation, Inc. +# Copyright (C) 1995-2004,2006-2009,2011 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 @@ -58,7 +58,7 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \ tst-memstream1 tst-memstream2 \ tst-wmemstream1 tst-wmemstream2 \ bug-memstream1 bug-wmemstream1 \ - tst-setvbuf1 tst-popen1 tst-fgetwc bug-wsetpos + tst-setvbuf1 tst-popen1 tst-fgetwc bug-wsetpos bug-fclose1 test-srcs = test-freopen all: # Make this the default target; it will be defined in Rules. diff --git a/libio/bug-fclose1.c b/libio/bug-fclose1.c new file mode 100644 index 00000000000..f1e09f5d476 --- /dev/null +++ b/libio/bug-fclose1.c @@ -0,0 +1,132 @@ +// BZ #12724 + +static void do_prepare (void); +#define PREPARE(argc, argv) do_prepare () +static int do_test (void); +#define TEST_FUNCTION do_test() +#include "../test-skeleton.c" + + +static int fd; + + +static void +do_prepare (void) +{ + fd = create_temp_file ("bug-fclose1.", NULL); + if (fd == -1) + { + printf ("cannot create temporary file: %m\n"); + exit (1); + } +} + + +static int +do_test (void) +{ + static const char pattern[] = "hello world"; + + /* Prepare a seekable file. */ + if (write (fd, pattern, sizeof pattern) != sizeof pattern) + { + printf ("cannot write pattern: %m\n"); + return 1; + } + if (lseek (fd, 1, SEEK_SET) != 1) + { + printf ("cannot seek after write: %m\n"); + return 1; + } + + /* Create an output stream visiting the file; when it is closed, all + other file descriptors visiting the file must see the new file + position. */ + int fd2 = dup (fd); + if (fd2 < 0) + { + printf ("cannot duplicate descriptor for writing: %m\n"); + return 1; + } + FILE *f = fdopen (fd2, "w"); + if (f == NULL) + { + printf ("first fdopen failed: %m\n"); + return 1; + } + if (fputc (pattern[1], f) != pattern[1]) + { + printf ("fputc failed: %m\n"); + return 1; + } + if (fclose (f) != 0) + { + printf ("first fclose failed: %m\n"); + return 1; + } + errno = 0; + if (lseek (fd2, 0, SEEK_CUR) != -1) + { + printf ("lseek after fclose after write did not fail\n"); + return 1; + } + if (errno != EBADF) + { + printf ("lseek after fclose after write did not fail with EBADF: %m\n"); + return 1; + } + off_t o = lseek (fd, 0, SEEK_CUR); + if (o != 2) + { + printf ("\ +lseek on original descriptor after first fclose returned %ld, expected 2\n", + (long int) o); + return 1; + } + + /* Likewise for an input stream. */ + fd2 = dup (fd); + if (fd2 < 0) + { + printf ("cannot duplicate descriptor for reading: %m\n"); + return 1; + } + f = fdopen (fd2, "r"); + if (f == NULL) + { + printf ("second fdopen failed: %m\n"); + return 1; + } + char c = fgetc (f); + if (c != pattern[2]) + { + printf ("getc returned %c, expected %c\n", c, pattern[2]); + return 1; + } + if (fclose (f) != 0) + { + printf ("second fclose failed: %m\n"); + return 1; + } + errno = 0; + if (lseek (fd2, 0, SEEK_CUR) != -1) + { + printf ("lseek after fclose after read did not fail\n"); + return 1; + } + if (errno != EBADF) + { + printf ("lseek after fclose after read did not fail with EBADF: %m\n"); + return 1; + } + o = lseek (fd, 0, SEEK_CUR); + if (o != 3) + { + printf ("\ +lseek on original descriptor after second fclose returned %ld, expected 3\n", + (long int) o); + return 1; + } + + return 0; +} diff --git a/libio/fileops.c b/libio/fileops.c index 1e7ef0754cd..adf4cfaea95 100644 --- a/libio/fileops.c +++ b/libio/fileops.c @@ -160,19 +160,25 @@ int _IO_new_file_close_it (fp) _IO_FILE *fp; { - int write_status, close_status; if (!_IO_file_is_open (fp)) return EOF; - if ((fp->_flags & _IO_NO_WRITES) == 0 - && (fp->_flags & _IO_CURRENTLY_PUTTING) != 0) + int write_status; + if (_IO_in_put_mode (fp)) write_status = _IO_do_flush (fp); - else - write_status = 0; + else if (fp->_offset != _IO_pos_BAD && fp->_IO_read_base != NULL + && !_IO_in_backup (fp)) + { + off64_t o = _IO_SEEKOFF (fp, 0, _IO_seek_cur, 0); + if (o == WEOF) + write_status = EOF; + else + write_status = _IO_SYSSEEK (fp, o, SEEK_SET) < 0 ? EOF : 0; + } INTUSE(_IO_unsave_markers) (fp); - close_status = _IO_SYSCLOSE (fp); + int close_status = _IO_SYSCLOSE (fp); /* Free buffer. */ #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T