3 files changed, 31 insertions, 6 deletions
diff --git a/shell/ash.c b/shell/ash.c
index 559566b58..40b921be1 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -5190,8 +5190,7 @@ forkchild(struct job *jp, union node *n, int mode)
        closescript();
-        if (mode == FORK_NOJOB          /* is it `xxx` ? */
+        if (n && n->type == NCMD        /* is it single cmd? */
-         && n && n->type == NCMD        /* is it single cmd? */
        /* && n->ncmd.args->type == NARG - always true? */
         && n->ncmd.args && strcmp(n->ncmd.args->narg.text, "trap") == 0
         && n->ncmd.args->narg.next == NULL /* "trap" with no arguments */
@@ -5285,10 +5284,12 @@ forkchild(struct job *jp, union node *n, int mode)
        ) {
                TRACE(("Job hack\n"));
                /* "jobs": we do not want to clear job list for it,
-                 * instead we remove only _its_ own_ job from job list.
+                 * instead we remove only _its_ own_ job from job list
+                 * (if it has one).
                 * This makes "jobs .... | cat" more useful.
                 */
-                freejob(curjob);
+                if (jp)
+                        freejob(curjob);
                return;
        }
 #endif
@@ -6607,9 +6608,9 @@ evalbackcmd(union node *n, struct backcmd *result
        if (pipe(pip) < 0)
                ash_msg_and_raise_perror("can't create pipe");
-        /* process substitution uses NULL job/node, like openhere() */
+        /* process substitution uses NULL job, like openhere() */
        jp = (ctl == CTLBACKQ) ? makejob(/*n,*/ 1) : NULL;
-        if (forkshell(jp, (ctl == CTLBACKQ) ? n : NULL, FORK_NOJOB) == 0) {
+        if (forkshell(jp, n, FORK_NOJOB) == 0) {
                /* child */
                FORCE_INT_ON;
                close(pip[ip]);
diff --git a/shell/ash_test/ash-signals/usage.right b/shell/ash_test/ash-signals/usage.right
index c0dbd6c3c..df1ed2dd7 100644
--- a/shell/ash_test/ash-signals/usage.right
+++ b/shell/ash_test/ash-signals/usage.right
@@ -6,6 +6,18 @@ trap -- 'a' INT
 trap -- 'a' USR1
 trap -- 'a' USR2
 ___
+trap -- 'a' EXIT trap -- 'a' INT trap -- 'a' USR1 trap -- 'a' USR2
+___
+trap -- 'a' EXIT
+trap -- 'a' INT
+trap -- 'a' USR1
+trap -- 'a' USR2
+___
+trap -- 'a' EXIT
+trap -- 'a' INT
+trap -- 'a' USR1
+trap -- 'a' USR2
+___
 ___
 trap -- 'a' USR1
 trap -- 'a' USR2
diff --git a/shell/ash_test/ash-signals/usage.tests b/shell/ash_test/ash-signals/usage.tests
index d29c6e74a..34e24cceb 100755
--- a/shell/ash_test/ash-signals/usage.tests
+++ b/shell/ash_test/ash-signals/usage.tests
@@ -10,6 +10,18 @@ trap "a" EXIT INT USR1 USR2
 echo ___
 trap
+# show them by command substitution
+echo ___
+echo $(trap)
+# show them by pipe
+echo ___
+trap | cat
+# show them by process substitution
+echo ___
+cat <(trap)
 # clear one
 echo ___
 trap 0 INT