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authorUlrich Drepper <drepper@gmail.com>2011-05-13 21:08:45 -0400
committerUlrich Drepper <drepper@gmail.com>2011-05-13 21:08:45 -0400
commitfcabc0f8b185f9e0a9289720be5ede6c39b3bf21 (patch)
treecaaf6f36c3e13a77ab677c5049dfa0f5922bf021 /libio
parent320a5dc07b907b1e640fd11ce49a04aa2b367711 (diff)
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Fix file descriptor position after fclose
fclose should leave the file descriptor position after the last read or written byte.
Diffstat (limited to 'libio')
-rw-r--r--libio/Makefile4
-rw-r--r--libio/bug-fclose1.c132
-rw-r--r--libio/fileops.c18
3 files changed, 146 insertions, 8 deletions
diff --git a/libio/Makefile b/libio/Makefile
index 83b9458..ec30904 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 0000000..f1e09f5
--- /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 ea730ac..678e32a 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