Handle errno and exit status a bit more carefully.

* lib/ignore-value.h: Remove this gnulib-imported file.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* admin/merge-gnulib (GNULIB_MODULES): Remove ignore-value.
* src/callproc.c (child_setup) [!DOS_NT]: Don't try to stuff an error
number into an exit status.  Instead, use EXIT_CANCELED.
(child_setup) [!MSDOS]: Avoid possible deadlock with vfork.
* src/callproc.c (relocate_fd):
* src/emacs.c (close_output_streams, main):
* src/process.c (create_process):
* src/sysdep.c (sys_subshell) [!DOS_NT || !WINDOWSNT]:
Use emacs_perror for simplicity.
* src/callproc.c (relocate_fd, main):
* src/sysdep.c (sys_subshell):
Exit with EXIT_CANCELED etc., not 1, when exec setup fails.
(shut_down_emacs): Use emacs_write, not write.
* src/emacs.c, src/sysdep.c: Don't include <ignore-value.h>.
* src/fileio.c (Fcopy_file, e_write):
* src/nsterm.m (ns_select):
* src/process.c (send_process):
* src/sound.c (vox_write):
Use emacs_write_sig, not emacs_write.
* src/lisp.h (emacs_write_sig, emacs_perror): New decls.
* src/process.h (EXIT_CANCELED), EXIT_CANNOT_INVOKE, EXIT_ENOENT):
New constants.
* src/sysdep.c (emacs_backtrace): Use emacs_write, not ignore_value
of write.
(emacs_full_write): New function.
(emacs_write): Rewrite to use it.
(emacswrite_sig, emacs_perror): New functions.
* src/xrdb.c (fatal): Don't invoke perror, since errno might be garbage.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/process.h b/src/process.h
index e7ee5f9adde..8ae33aebf39 100644
--- a/src/process.h
+++ b/src/process.h
@@ -198,6 +198,14 @@ extern Lisp_Object QCspeed;
 extern Lisp_Object QCbytesize, QCstopbits, QCparity, Qodd, Qeven;
 extern Lisp_Object QCflowcontrol, Qhw, Qsw, QCsummary;
 
+/* Exit statuses for GNU programs that exec other programs.  */
+enum
+{
+  EXIT_CANCELED = 125, /* Internal error prior to exec attempt.  */
+  EXIT_CANNOT_INVOKE = 126, /* Program located, but not usable.  */
+  EXIT_ENOENT = 127 /* Could not find program to exec.  */
+};
+
 /* Defined in callproc.c.  */
 
 extern void block_child_signal (void);