hush: stop ignoring ^Z in child shells

1 files changed, 19 insertions, 8 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 16f304d81..a5d5741da 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2276,15 +2276,28 @@ void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
 
 static void reset_traps_to_defaults(void)
 {
+        enum {
+                JOBSIGS = (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
+        };
         unsigned sig;
-        int dirty;
 
-        if (!G.traps)
+        if (!G.traps && !(G.non_DFL_mask & JOBSIGS))
                 return;
-        dirty = 0;
-        for (sig = 0; sig < NSIG; sig++) {
-                if (!G.traps[sig])
+
+        /* This function is always called in a child shell.
+         * Child shells are not interactive.
+         * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
+         * Testcase: (while :; do :; done) + ^Z should background.
+         */
+        G.non_DFL_mask &= ~JOBSIGS;
+        sigdelset(&G.blocked_set, SIGTTIN);
+        sigdelset(&G.blocked_set, SIGTTOU);
+        sigdelset(&G.blocked_set, SIGTSTP);
+
+        if (G.traps) for (sig = 0; sig < NSIG; sig++) {
+                if (!G.traps[sig]) {
                         continue;
+                }
                 free(G.traps[sig]);
                 G.traps[sig] = NULL;
                 /* There is no signal for 0 (EXIT) */
@@ -2296,10 +2309,8 @@ static void reset_traps_to_defaults(void)
                 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
                         continue;
                 sigdelset(&G.blocked_set, sig);
-                dirty = 1;
         }
-        if (dirty)
-                sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+        sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
 }
 
 #else /* !BB_MMU */