ash: partially sync with dash on "fork if traps are set" logic

Upstream commit "[EVAL] Force fork if any trap is set, not just on EXIT"
had a similar code as our fix to that bug.
Eliminate some superficial differences.

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

1 files changed, 6 insertions, 5 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 0dd440c61..c575e1036 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -4660,19 +4660,19 @@ clear_traps(void)
 {
         char **tp;
 
+        INT_OFF;
         for (tp = trap; tp < &trap[NSIG]; tp++) {
                 if (*tp && **tp) {      /* trap not NULL or "" (SIG_IGN) */
-                        INT_OFF;
                         if (trap_ptr == trap)
                                 free(*tp);
                         /* else: it "belongs" to trap_ptr vector, don't free */
                         *tp = NULL;
                         if ((tp - trap) != 0)
                                 setsignal(tp - trap);
-                        INT_ON;
                 }
         }
         may_have_traps = 0;
+        INT_ON;
 }
 
 /* Lives far away from here, needed for forkchild */
@@ -12753,12 +12753,13 @@ trapcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                 if (action) {
                         if (LONE_DASH(action))
                                 action = NULL;
-                        else
+                        else {
+                                if (action[0]) /* not NULL and not "" and not "-" */
+                                        may_have_traps = 1;
                                 action = ckstrdup(action);
+                        }
                 }
                 free(trap[signo]);
-                if (action)
-                        may_have_traps = 1;
                 trap[signo] = action;
                 if (signo != 0)
                         setsignal(signo);