Assume at least POSIX.1-1988 for getpgrp, setpgid, setsid.

This removes code that has been obsolete since around 1990.
* admin/CPP-DEFINES (HAVE_SETPGID, HAVE_SETSID, SETPGRP_RELEASES_CTTY):
Remove; obsolete.
* configure.ac (setpgid, setsid): Assume their existence.
(AC_FUNC_GETPGRP, SETPGRP_RELEASES_CTTY): Remove; obsolete.
* src/callproc.c (Fcall_process):
* src/emacs.c (main):
* src/process.c (create_process):
* src/term.c (dissociate_if_controlling_tty):
Assume setsid exists.
* src/callproc.c (child_setup): Assume setpgid exists and behaves as
per POSIX.1-1988 or later.
* src/conf_post.h (setpgid) [!HAVE_SETPGID]: Remove.
* src/emacs.c (shut_down_emacs):
* src/sysdep.c (sys_suspend, init_foreground_group):
Assume getpgrp behaves as per POSIX.1-1998 or later.
* src/msdos.c (setpgrp): Remove.
(tcgetpgrp, setpgid, setsid): New functions.
* src/systty.h (EMACS_GETPGRP): Remove.  All callers now use getpgrp.
* src/term.c (no_controlling_tty): Remove; unused.
* src/w32proc.c (setpgrp): Remove.
(setsid, tcgetpgrp): New functions.

Fixes: debbugs:12800

1 files changed, 1 insertions, 9 deletions

diff --git a/src/callproc.c b/src/callproc.c
index c236f22fc86..c7bbe36e605 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -612,11 +612,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
         if (fd[0] >= 0)
           emacs_close (fd[0]);
 
-#ifdef HAVE_SETSID
         setsid ();
-#else
-        setpgid (0, 0);
-#endif
 
         /* Emacs ignores SIGPIPE, but the child should not.  */
         signal (SIGPIPE, SIG_DFL);
@@ -1286,11 +1282,7 @@ child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
   if (err != in && err != out)
     emacs_close (err);
 
-#if defined HAVE_SETPGID || ! (defined USG && defined SETPGRP_RELEASES_CTTY)
-  setpgid (pid, pid);
-#endif
-
-  /* setpgrp_of_tty is incorrect here; it uses input_fd.  */
+  setpgid (0, 0);
   tcsetpgrp (0, pid);
 
   /* execvp does not accept an environment arg so the only way