fixed bug #34355: nagle does not take snd_buf/snd_queuelen into account

CHANGELOG

@@ -65,6 +65,10 @@ HISTORY
 
  ++ Bugfixes:
 
+  2011-09-22: Simon Goldschmidt
+  * tcp_impl.h: fixed bug #34355: nagle does not take snd_buf/snd_queuelen into
+    account
+
   2011-09-21: Simon Goldschmidt
   * opt.h: fixed default value of TCP_SND_BUF to not violate the sanity checks
     in init.c

src/include/lwip/tcp_impl.h

@@ -85,7 +85,8 @@ u32_t            tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb);
 #define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
                             ((tpcb)->flags & (TF_NODELAY | TF_INFR)) || \
                             (((tpcb)->unsent != NULL) && (((tpcb)->unsent->next != NULL) || \
-                              ((tpcb)->unsent->len >= (tpcb)->mss))) \
+                              ((tpcb)->unsent->len >= (tpcb)->mss))) || \
+                            ((tcp_sndbuf(tpcb) == 0) || (tcp_sndqueuelen(tpcb) >= TCP_SND_QUEUELEN)) \
                             ) ? 1 : 0)
 #define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)