hush: remove special handling of SIGHUP

Kernel should do the right thing.
(ash and dash do not have special SIGHUP handling.)

function                                             old     new   delta
check_and_run_traps                                  278     214     -64

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 20 insertions, 18 deletions

diff --git a/shell/hush.c b/shell/hush.c
index f064b8fd2..9b87e28cf 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1830,6 +1830,8 @@ static void restore_G_args(save_arg_t *sv, char **argv)
  * SIGTERM (interactive): ignore
  * SIGHUP (interactive):
  *    send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
+//HUP: we don't need to do this, kernel does this for us
+//HUP: ("orphaned process group" handling according to POSIX)
  * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
  *    Note that ^Z is handled not by trapping SIGTSTP, but by seeing
  *    that all pipe members are stopped. Try this in bash:
@@ -1931,7 +1933,7 @@ enum {
         SPECIAL_INTERACTIVE_SIGS = 0
                 | (1 << SIGTERM)
                 | (1 << SIGINT)
-                | (1 << SIGHUP)
+//HUP           | (1 << SIGHUP)
                 ,
         SPECIAL_JOBSTOP_SIGS = 0
 #if ENABLE_HUSH_JOB
@@ -2177,23 +2179,23 @@ static int check_and_run_traps(void)
                         last_sig = sig;
                         break;
 #if ENABLE_HUSH_JOB
-                case SIGHUP: {
-//TODO: why are we doing this? ash and dash don't do this,
-//they have no handler for SIGHUP at all,
-//they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
-                        struct pipe *job;
-                        debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
-                        /* bash is observed to signal whole process groups,
-                         * not individual processes */
-                        for (job = G.job_list; job; job = job->next) {
-                                if (job->pgrp <= 0)
-                                        continue;
-                                debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
-                                if (kill(- job->pgrp, SIGHUP) == 0)
-                                        kill(- job->pgrp, SIGCONT);
-                        }
-                        sigexit(SIGHUP);
-                }
+//HUP           case SIGHUP: {
+//HUP//TODO: why are we doing this? ash and dash don't do this,
+//HUP//they have no handler for SIGHUP at all,
+//HUP//they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
+//HUP                   struct pipe *job;
+//HUP                   debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
+//HUP                   /* bash is observed to signal whole process groups,
+//HUP                    * not individual processes */
+//HUP                   for (job = G.job_list; job; job = job->next) {
+//HUP                           if (job->pgrp <= 0)
+//HUP                                   continue;
+//HUP                           debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
+//HUP                           if (kill(- job->pgrp, SIGHUP) == 0)
+//HUP                                   kill(- job->pgrp, SIGCONT);
+//HUP                   }
+//HUP                   sigexit(SIGHUP);
+//HUP           }
 #endif
 #if ENABLE_HUSH_FAST
                 case SIGCHLD: