1 files changed, 13 insertions, 7 deletions

diff --git a/src/lib/libc/stdlib/insque.c b/src/lib/libc/stdlib/insque.c
index 8724efec74..590ff837b8 100644
--- a/src/lib/libc/stdlib/insque.c
+++ b/src/lib/libc/stdlib/insque.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: insque.c,v 1.2 2005/08/08 08:05:36 espie Exp $        */
+/*      $OpenBSD: insque.c,v 1.3 2014/08/15 04:14:36 guenther Exp $     */
 
 /*
  *  Copyright (c) 1993 John Brezak
@@ -28,6 +28,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <stdlib.h>
 #include <search.h>
 
 struct qelem {
@@ -38,11 +39,16 @@ struct qelem {
 void
 insque(void *entry, void *pred)
 {
-        struct qelem *e = (struct qelem *) entry;
-        struct qelem *p = (struct qelem *) pred;
+        struct qelem *e = entry;
+        struct qelem *p = pred;
 
-        e->q_forw = p->q_forw;
-        e->q_back = p;
-        p->q_forw->q_back = e;
-        p->q_forw = e;
+        if (p == NULL)
+                e->q_forw = e->q_back = NULL;
+        else {
+                e->q_forw = p->q_forw;
+                e->q_back = p;
+                if (p->q_forw != NULL)
+                        p->q_forw->q_back = e;
+                p->q_forw = e;
+        }
 }