[PATCH] do not ignore errors like ENOSPC,EIO when writing to stdout

[Jim Meyering]

This is incomplete in that I haven't added a test for it
and haven't updated NEWS -- since its effect is limited,
I'm not sure it's worthy of a NEWS entry.

Before:

    $ bison --print-datadir > /dev/full
    $ bison --print-datadir >&-
    $

After:

    $ bison --print-datadir > /dev/full
    bison: write error: No space left on device
    [Exit 1]
    $ bison --print-datadir >&-
    bison: write error: Bad file descriptor
    [Exit 1]
    $

>From 581dfdb383842aced19443db6f910fbd02736e23 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sun, 29 Jan 2012 12:50:32 +0100
Subject: [PATCH] do not ignore errors like ENOSPC,EIO when writing to stdout

Standard output was never explicitly closed, so we could not
detect failure.  Thus, bison would ignore the errors of writing
to a full file system and getting an I/O error on write, but only
for standard output, e.g., for --print-localedir, --print-datadir,
--help and some verbose output.
Now, "bison --print-datadir > /dev/full" reports the write failure:
bison: write error: No space left on device
Before, it would exit 0 with no diagnostic, implying success.
This is not an issue for "--output=-" or the other FILE-accepting
command-line options, because unlike most other GNU programs,
an output file argument of "-" is treated as the literal "./-",
rather than standard output.
* bootstrap.conf (gnulib_modules): Add closeout.
* src/main.c: Include "closeout.h".
Use atexit to ensure we close stdout.
* .gitignore: Ignore new files pulled in via gnulib-tool.
---
 bootstrap.conf |    2 +-
 lib/.gitignore |    6 ++++++
 m4/.gitignore  |    3 +++
 src/main.c     |    3 +++
 4 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/bootstrap.conf b/bootstrap.conf
index 599b778..757111c 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -17,7 +17,7 @@

 # gnulib modules used by this package.
 gnulib_modules='
-  announce-gen argmatch assert calloc-posix close config-h c-strcase
+  announce-gen argmatch assert calloc-posix close closeout config-h c-strcase
   configmake dirname error extensions fdl fopen-safer gendocs getopt-gnu
   gettext git-version-gen gitlog-to-changelog
   gpl-3.0 hash inttypes isnan javacomp-script
diff --git a/lib/.gitignore b/lib/.gitignore
index 54edced..365b84d 100644
--- a/lib/.gitignore
+++ b/lib/.gitignore
@@ -259,3 +259,9 @@
 /strerror-override.h
 /strerror_r.c
 /xalloc-oversized.h
+/close-stream.c
+/close-stream.h
+/closeout.c
+/closeout.h
+/fpending.c
+/fpending.h
diff --git a/m4/.gitignore b/m4/.gitignore
index c50ed39..901724d 100644
--- a/m4/.gitignore
+++ b/m4/.gitignore
@@ -166,3 +166,6 @@
 /raise.m4
 /ssize_t.m4
 /strerror_r.m4
+/close-stream.m4
+/closeout.m4
+/fpending.m4
diff --git a/src/main.c b/src/main.c
index e777ca0..3dbac3a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -28,6 +28,7 @@
 #include <timevar.h>

 #include "LR0.h"
+#include "closeout.h"
 #include "complain.h"
 #include "conflicts.h"
 #include "derives.h"
@@ -62,6 +63,8 @@ main (int argc, char *argv[])
   (void) bindtextdomain ("bison-runtime", LOCALEDIR);
   (void) textdomain (PACKAGE);

+  atexit (close_stdout);
+
   uniqstrs_new ();
   muscle_init ();

--
1.7.9.1.g63eb