From 515fb5a3fd495cd0a2b9dcc479fc9b61411f8e5d Mon Sep 17 00:00:00 2001
From: likewise <likewise>
Date: Tue, 17 Aug 2004 08:39:43 +0000
Subject: [PATCH] First packet on queue generated assertion failure. Reported
 by David Haas on lwip-users on Friday 13th.

---
 src/netif/etharp.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/netif/etharp.c b/src/netif/etharp.c
index 40d84b3d..a3fbbf2a 100644
--- a/src/netif/etharp.c
+++ b/src/netif/etharp.c
@@ -752,8 +752,14 @@ err_t etharp_query(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
       p = pbuf_take(q);
       /* packet could be taken over? */
       if (p != NULL) {
-        /* queue packet */
-        pbuf_queue(arp_table[i].p, p);
+        /* queue packet ... */
+        if (arp_table[i].p == NULL) {
+        	/* ... in the empty queue */
+        	arp_table[i].p = p;
+        } else {
+        	/* ... at tail of non-empty queue */
+          pbuf_queue(arp_table[i].p, p);
+        }
         LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %d\n", (void *)q, i));
         result = ERR_OK;
       } else {