[lwip-users] bug about pbuf_queue() fuction

[xcb]

lwip-users
   pbuf_queue() function in pbuf.c

if ((p == NULL) || (n == NULL) ) return;
should be write to:
if ((p == NULL) || (n == NULL) || (p==n)) return;

p->next can not point to self,
for(q = p; q != NULL; q = q->next) {
    acc += lwip_chksum(q->payload, q->len);
    while (acc >> 16) {
      acc = (acc & 0xffffUL) + (acc >> 16);
    }
    if (q->len % 2 != 0) {
      swapped = 1 - swapped;
      acc = (acc & 0x00ffUL << 8) | (acc & 0xff00UL >> 8);
    }
  }

if p->next point to self ,will not out of for()(up code),

if you dont insert netLine to netword card,and excute connect() function ,it 
dont return forever,because of up code.