only leave ms_std's if prodepth > 0

diff --git a/util/opt/backward.c b/util/opt/backward.c
index b6c117a..632889e 100644 (file)
--- a/util/opt/backward.c
+++ b/util/opt/backward.c
@@ -161,7 +161,8 @@ backward() {
                        goodrom = (rc >= 2);
                        break;
                case ps_mes:
-                       if ((int) aoff(lnp->l_a.la_arg, 0) == ms_std) {
+                       if (prodepth != 0 &&
+                           (int) aoff(lnp->l_a.la_arg, 0) == ms_std) {
                                lnp->l_next = i;
                                i = lnp;
                                continue;