Merge branch 'busybox' into merge

2 files changed, 37 insertions, 17 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 87190c453..94eb49d79 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11769,7 +11769,8 @@ preadfd(void)
  again:
                 /* For shell, LI_INTERRUPTIBLE is set:
                  * read_line_input will abort on either
-                 * getting EINTR in poll(), or if it sees bb_got_signal != 0
+                 * getting EINTR in poll() and bb_got_signal became != 0,
+                 * or if it sees bb_got_signal != 0
                  * (IOW: if signal arrives before poll() is reached).
                  * Interactive testcases:
                  * (while kill -INT $$; do sleep 1; done) &
diff --git a/shell/hush.c b/shell/hush.c
index d111f0cc5..e6be70078 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1829,7 +1829,13 @@ static void restore_G_args(save_arg_t *sv, char **argv)
  * SIGQUIT: ignore
  * SIGTERM (interactive): ignore
  * SIGHUP (interactive):
- *    send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
+ *    Send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit.
+ *    Kernel would do this for us ("orphaned process group" handling
+ *    according to POSIX) if we are a session leader and thus our death
+ *    frees the controlling tty, but to be bash-compatible, we also do it
+ *    for every interactive shell's death by SIGHUP.
+ *    (Also, we need to restore tty pgrp, otherwise e.g. Midnight Commander
+ *    backgrounds when hush started from it gets killed by SIGHUP).
  * 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:
@@ -1946,7 +1952,12 @@ static void record_pending_signo(int sig)
 {
         sigaddset(&G.pending_set, sig);
 #if ENABLE_FEATURE_EDITING
-        bb_got_signal = sig; /* for read_line_input: "we got a signal" */
+        if (sig != SIGCHLD
+         || (G_traps && G_traps[SIGCHLD] && G_traps[SIGCHLD][0])
+         /* ^^^ if SIGCHLD, interrupt line reading only if it has a trap */
+        ) {
+                bb_got_signal = sig; /* for read_line_input: "we got a signal" */
+        }
 #endif
 #if ENABLE_HUSH_FAST
         if (sig == SIGCHLD) {
@@ -2173,20 +2184,27 @@ static int check_and_run_traps(void)
                         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);
+                        /* if (G_interactive_fd) - no need to check, the handler
+                         * is only installed if we *are* interactive */
+                        {
+                                /* bash compat: "Before exiting, an interactive
+                                 * shell resends the SIGHUP to all jobs, running
+                                 * or stopped.  Stopped jobs are sent SIGCONT
+                                 * to ensure that they receive the SIGHUP."
+                                 */
+                                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);
+                                }
                         }
+                        /* this restores tty pgrp, then kills us with SIGHUP */
                         sigexit(SIGHUP);
                 }
 #endif
@@ -2669,7 +2687,8 @@ static int get_user_input(struct in_str *i)
                 } else {
                         /* For shell, LI_INTERRUPTIBLE is set:
                          * read_line_input will abort on either
-                         * getting EINTR in poll(), or if it sees bb_got_signal != 0
+                         * getting EINTR in poll() and bb_got_signal became != 0,
+                         * or if it sees bb_got_signal != 0
                          * (IOW: if signal arrives before poll() is reached).
                          * Interactive testcases:
                          * (while kill -INT $$; do sleep 1; done) &