Commit 7ccfb720 authored by Paul Eggert's avatar Paul Eggert

Fix data-loss with --batch.

* admin/merge-gnulib (GNULIB_MODULES): Add close-stream.
* lib/close-stream.c, lib/close-stream.h, lib/fpending.c
* lib/fpending.h, m4/close-stream.m4, m4/fpending.m4:
New files, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* src/emacs.c: Include <close-stream.h>.
(close_output_streams): New function.
(main): Pass it to atexit, so that Emacs closes stdout and stderr
and handles errors appropriately.
(Fkill_emacs): Don't worry about flushing, as close_output_stream
does that now.

Fixes: debbugs:9574
parent 376a8e83
2012-11-03 Paul Eggert <eggert@cs.ucla.edu>
Fix data-loss with --batch (Bug#9574).
* lib/close-stream.c, lib/close-stream.h, lib/fpending.c
* lib/fpending.h, m4/close-stream.m4, m4/fpending.m4:
New files, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
2012-11-02 Glenn Morris <rgm@gnu.org>
* Makefile.in (EMACS_ICON): New variable.
......
2012-11-01 Paul Eggert <eggert@cs.ucla.edu>
Fix data-loss with --batch (Bug#9574).
* merge-gnulib (GNULIB_MODULES): Add close-stream.
2012-10-12 Kenichi Handa <handa@gnu.org>
* charsets/Makefile (JISC6226.map): Add missing mappings.
......
......@@ -27,7 +27,7 @@ GNULIB_URL=git://git.savannah.gnu.org/gnulib.git
GNULIB_MODULES='
alloca-opt c-ctype c-strcase
careadlinkat crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512
careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512
dtoastr dtotimespec dup2 environ execinfo
filemode getloadavg getopt-gnu gettime gettimeofday
ignore-value intprops largefile lstat
......
/* Close a stream, with nicer error checking than fclose's.
Copyright (C) 1998-2002, 2004, 2006-2012 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include "close-stream.h"
#include <errno.h>
#include <stdbool.h>
#include "fpending.h"
#if USE_UNLOCKED_IO
# include "unlocked-io.h"
#endif
/* Close STREAM. Return 0 if successful, EOF (setting errno)
otherwise. A failure might set errno to 0 if the error number
cannot be determined.
A failure with errno set to EPIPE may or may not indicate an error
situation worth signaling to the user. See the documentation of the
close_stdout_set_ignore_EPIPE function for details.
If a program writes *anything* to STREAM, that program should close
STREAM and make sure that it succeeds before exiting. Otherwise,
suppose that you go to the extreme of checking the return status
of every function that does an explicit write to STREAM. The last
printf can succeed in writing to the internal stream buffer, and yet
the fclose(STREAM) could still fail (due e.g., to a disk full error)
when it tries to write out that buffered data. Thus, you would be
left with an incomplete output file and the offending program would
exit successfully. Even calling fflush is not always sufficient,
since some file systems (NFS and CODA) buffer written/flushed data
until an actual close call.
Besides, it's wasteful to check the return value from every call
that writes to STREAM -- just let the internal stream state record
the failure. That's what the ferror test is checking below. */
int
close_stream (FILE *stream)
{
const bool some_pending = (__fpending (stream) != 0);
const bool prev_fail = (ferror (stream) != 0);
const bool fclose_fail = (fclose (stream) != 0);
/* Return an error indication if there was a previous failure or if
fclose failed, with one exception: ignore an fclose failure if
there was no previous error, no data remains to be flushed, and
fclose failed with EBADF. That can happen when a program like cp
is invoked like this 'cp a b >&-' (i.e., with standard output
closed) and doesn't generate any output (hence no previous error
and nothing to be flushed). */
if (prev_fail || (fclose_fail && (some_pending || errno != EBADF)))
{
if (! fclose_fail)
errno = 0;
return EOF;
}
return 0;
}
#include <stdio.h>
int close_stream (FILE *stream);
/* fpending.c -- return the number of pending output bytes on a stream
Copyright (C) 2000, 2004, 2006-2007, 2009-2012 Free Software Foundation,
Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Jim Meyering. */
#include <config.h>
#include "fpending.h"
/* Return the number of pending (aka buffered, unflushed)
bytes on the stream, FP, that is open for writing. */
size_t
__fpending (FILE *fp)
{
return PENDING_OUTPUT_N_BYTES;
}
/* Declare __fpending.
Copyright (C) 2000, 2003, 2005-2006, 2009-2012 Free Software Foundation,
Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
Written by Jim Meyering. */
#include <stddef.h>
#include <stdio.h>
#if HAVE_DECL___FPENDING
# if HAVE_STDIO_EXT_H
# include <stdio_ext.h>
# endif
#else
size_t __fpending (FILE *);
#endif
......@@ -21,7 +21,7 @@
# the same distribution terms as the rest of that program.
#
# Generated by gnulib-tool.
# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=errno --avoid=fcntl --avoid=fcntl-h --avoid=fstat --avoid=msvc-inval --avoid=msvc-nothrow --avoid=raise --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo filemode getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask readlink socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub utimens warnings
# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=errno --avoid=fcntl --avoid=fcntl-h --avoid=fstat --avoid=msvc-inval --avoid=msvc-nothrow --avoid=raise --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo filemode getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask readlink socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub utimens warnings
MOSTLYCLEANFILES += core *.stackdump
......@@ -84,6 +84,14 @@ EXTRA_DIST += careadlinkat.h
## end gnulib module careadlinkat
## begin gnulib module close-stream
libgnu_a_SOURCES += close-stream.c
EXTRA_DIST += close-stream.h
## end gnulib module close-stream
## begin gnulib module crypto/md5
libgnu_a_SOURCES += md5.c
......@@ -183,6 +191,15 @@ EXTRA_DIST += filemode.h
## end gnulib module filemode
## begin gnulib module fpending
EXTRA_DIST += fpending.c fpending.h
EXTRA_libgnu_a_SOURCES += fpending.c
## end gnulib module fpending
## begin gnulib module getloadavg
......
#serial 4
dnl Copyright (C) 2006-2007, 2009-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl Prerequisites of lib/close-stream.c.
AC_DEFUN([gl_CLOSE_STREAM],
[
:
])
# serial 19
# Copyright (C) 2000-2001, 2004-2012 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
dnl From Jim Meyering
dnl Using code from emacs, based on suggestions from Paul Eggert
dnl and Ulrich Drepper.
dnl Find out how to determine the number of pending output bytes on a stream.
dnl glibc (2.1.93 and newer) and Solaris provide __fpending. On other systems,
dnl we have to grub around in the FILE struct.
AC_DEFUN([gl_FUNC_FPENDING],
[
AC_CHECK_HEADERS_ONCE([stdio_ext.h])
AC_CHECK_FUNCS_ONCE([__fpending])
fp_headers='
# include <stdio.h>
# if HAVE_STDIO_EXT_H
# include <stdio_ext.h>
# endif
'
AC_CHECK_DECLS([__fpending], , , $fp_headers)
])
AC_DEFUN([gl_PREREQ_FPENDING],
[
AC_CACHE_CHECK(
[how to determine the number of pending output bytes on a stream],
ac_cv_sys_pending_output_n_bytes,
[
for ac_expr in \
\
'# glibc2' \
'fp->_IO_write_ptr - fp->_IO_write_base' \
\
'# traditional Unix' \
'fp->_ptr - fp->_base' \
\
'# BSD' \
'fp->_p - fp->_bf._base' \
\
'# SCO, Unixware' \
'(fp->__ptr ? fp->__ptr - fp->__base : 0)' \
\
'# QNX' \
'(fp->_Mode & 0x2000 /*_MWRITE*/ ? fp->_Next - fp->_Buf : 0)' \
\
'# old glibc?' \
'fp->__bufp - fp->__buffer' \
\
'# old glibc iostream?' \
'fp->_pptr - fp->_pbase' \
\
'# emx+gcc' \
'fp->_ptr - fp->_buffer' \
\
'# Minix' \
'fp->_ptr - fp->_buf' \
\
'# Plan9' \
'fp->wp - fp->buf' \
\
'# VMS' \
'(*fp)->_ptr - (*fp)->_base' \
\
'# e.g., DGUX R4.11; the info is not available' \
1 \
; do
# Skip each embedded comment.
case "$ac_expr" in '#'*) continue;; esac
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
[[FILE *fp = stdin; (void) ($ac_expr);]])],
[fp_done=yes]
)
test "$fp_done" = yes && break
done
ac_cv_sys_pending_output_n_bytes=$ac_expr
]
)
AC_DEFINE_UNQUOTED([PENDING_OUTPUT_N_BYTES],
$ac_cv_sys_pending_output_n_bytes,
[the number of pending output bytes on stream 'fp'])
])
......@@ -44,6 +44,7 @@ AC_DEFUN([gl_EARLY],
# Code from module c-strcase:
# Code from module careadlinkat:
# Code from module clock-time:
# Code from module close-stream:
# Code from module crypto/md5:
# Code from module crypto/sha1:
# Code from module crypto/sha256:
......@@ -58,6 +59,7 @@ AC_DEFUN([gl_EARLY],
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
# Code from module extern-inline:
# Code from module filemode:
# Code from module fpending:
# Code from module getloadavg:
# Code from module getopt-gnu:
# Code from module getopt-posix:
......@@ -141,6 +143,8 @@ AC_DEFUN([gl_INIT],
gl_FUNC_ALLOCA
AC_CHECK_FUNCS_ONCE([readlinkat])
gl_CLOCK_TIME
gl_CLOSE_STREAM
gl_MODULE_INDICATOR([close-stream])
gl_MD5
gl_SHA1
gl_SHA256
......@@ -157,6 +161,11 @@ AC_DEFUN([gl_INIT],
gl_EXECINFO_H
AC_REQUIRE([gl_EXTERN_INLINE])
gl_FILEMODE
gl_FUNC_FPENDING
if test $ac_cv_func___fpending = no; then
AC_LIBOBJ([fpending])
gl_PREREQ_FPENDING
fi
gl_GETLOADAVG
if test $HAVE_GETLOADAVG = 0; then
AC_LIBOBJ([getloadavg])
......@@ -534,6 +543,8 @@ AC_DEFUN([gl_FILE_LIST], [
lib/c-strncasecmp.c
lib/careadlinkat.c
lib/careadlinkat.h
lib/close-stream.c
lib/close-stream.h
lib/dosname.h
lib/dtoastr.c
lib/dtotimespec.c
......@@ -542,6 +553,8 @@ AC_DEFUN([gl_FILE_LIST], [
lib/execinfo.in.h
lib/filemode.c
lib/filemode.h
lib/fpending.c
lib/fpending.h
lib/ftoastr.c
lib/ftoastr.h
lib/getloadavg.c
......@@ -609,12 +622,14 @@ AC_DEFUN([gl_FILE_LIST], [
m4/alloca.m4
m4/c-strtod.m4
m4/clock_time.m4
m4/close-stream.m4
m4/dup2.m4
m4/environ.m4
m4/execinfo.m4
m4/extensions.m4
m4/extern-inline.m4
m4/filemode.m4
m4/fpending.m4
m4/getloadavg.m4
m4/getopt.m4
m4/gettime.m4
......
2012-11-03 Paul Eggert <eggert@cs.ucla.edu>
Fix data-loss with --batch (Bug#9574).
* emacs.c: Include <close-stream.h>.
(close_output_streams): New function.
(main): Pass it to atexit, so that Emacs closes stdout and stderr
and handles errors appropriately.
(Fkill_emacs): Don't worry about flushing, as close_output_stream
does that now.
Fix a race condition that causes Emacs to mess up glib (Bug#8855).
The symptom is a diagnostic "GLib-WARNING **: In call to
g_spawn_sync(), exit status of a child process was requested but
......
......@@ -27,6 +27,7 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
#include <sys/file.h>
#include <unistd.h>
#include <close-stream.h>
#include <ignore-value.h>
#include "lisp.h"
......@@ -675,6 +676,22 @@ void (*__malloc_initialize_hook) (void) EXTERNALLY_VISIBLE = malloc_initialize_h
#endif /* DOUG_LEA_MALLOC */
/* Close standard output and standard error, reporting any write
errors as best we can. This is intended for use with atexit. */
static void
close_output_streams (void)
{
if (close_stream (stdout) != 0)
{
fprintf (stderr, "Write error to standard output: %s\n",
emacs_strerror (errno));
fflush (stderr);
_exit (EXIT_FAILURE);
}
if (close_stream (stderr) != 0)
_exit (EXIT_FAILURE);
}
/* ARGSUSED */
int
......@@ -890,6 +907,8 @@ main (int argc, char **argv)
if (do_initial_setlocale)
setlocale (LC_ALL, "");
atexit (close_output_streams);
inhibit_window_system = 0;
/* Handle the -t switch, which specifies filename to use as terminal. */
......@@ -1867,8 +1886,6 @@ all of which are called before Emacs is actually killed. */)
exit_code = (XINT (arg) < 0
? XINT (arg) | INT_MIN
: XINT (arg) & INT_MAX);
else if (noninteractive && (fflush (stdout) || ferror (stdout)))
exit_code = EXIT_FAILURE;
else
exit_code = EXIT_SUCCESS;
exit (exit_code);
......
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