Fix crash when using Emacs as commit editor for git.

* callproc.c (setpgrp): Remove macro, as we now use setpgid
and it is configured in conf_post.h.
(Fcall_process): Don't invoke both setsid and setpgid; the former
is enough, if it exists.
* callproc.c (Fcall_process, child_setup):
* process.c (create_process): Use setpgid.
* conf_post.h (setpgid) [!HAVE_SETPGID]: New macro, which substitutes
for the real thing.
* dispnew.c (init_display): Initialize the foreground group
if we are running a tty display.
* emacs.c (main): Do not worry about setpgrp; init_display does it now.
* lisp.h (init_foreground_group): New decl.
* sysdep.c (inherited_pgroup): New static var.
(init_foreground_group, tcsetpgrp_without_stopping)
(narrow_foreground_group, widen_foreground_group): New functions.
(init_sys_modes): Narrow foreground group.
(reset_sys_modes): Widen foreground group.

Fixes: debbugs:12697

1 files changed, 2 insertions, 8 deletions

diff --git a/src/process.c b/src/process.c
index 307e82819d6..77e99ead01f 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1759,12 +1759,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 #endif
         }
 #else /* not HAVE_SETSID */
-#ifdef USG
-      /* It's very important to call setpgrp here and no time
+      /* It's very important to call setpgid here and no time
          afterwards.  Otherwise, we lose our controlling tty which
          is set when we open the pty. */
-      setpgrp ();
-#endif /* USG */
+      setpgid (0, 0);
 #endif /* not HAVE_SETSID */
 #if defined (LDISC1)
       if (pty_flag && xforkin >= 0)
@@ -1802,11 +1800,7 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
           /* In order to get a controlling terminal on some versions
              of BSD, it is necessary to put the process in pgrp 0
              before it opens the terminal.  */
-#ifdef HAVE_SETPGID
           setpgid (0, 0);
-#else
-          setpgrp (0, 0);
-#endif
 #endif
         }
 #endif /* TIOCNOTTY */