--- net/ipv4/tcp_output.c-o	Wed Dec 10 11:40:57 1997
+++ net/ipv4/tcp_output.c	Wed Dec 10 12:19:47 1997
@@ -840,6 +840,7 @@
 	struct sk_buff *buff;
 	struct device *dev=NULL;
 	int tmp;
+	int probe0;
 		
 	buff = sock_wmalloc(sk, MAX_RESET_SIZE,1 , GFP_KERNEL);
 
@@ -914,11 +915,14 @@
 	tcp_send_check(t1, sk->saddr, sk->daddr, sizeof(*t1), buff);
 
 	/*
-	 * If there is data in the write queue, the fin must be appended to
-	 * the write queue.
+	 * If there is data in the write queue or the remote window is zero, 
+	 * the fin must be appended to the write queue.
  	 */
+
+	probe0 = before(sk->window_seq, sk->write_queue.next->end_seq) &&
+		    sk->send_head == NULL && sk->ack_backlog == 0;
  	
- 	if (skb_peek(&sk->write_queue) != NULL) 
+ 	if (probe0 || skb_peek(&sk->write_queue) != NULL) 
  	{
   		buff->free = 0;
 		if (buff->next != NULL) 
@@ -927,6 +931,14 @@
 			skb_unlink(buff);
 		}
 		skb_queue_tail(&sk->write_queue, buff);
+
+		/*
+		 * A FIN needs sequence space, so we must do zero window 
+		 * probing here if the window is 0 (sigh)
+		 */
+		if (probe0)
+			tcp_reset_xmit_timer(sk, TIME_PROBE0, sk->rto);
+
   	} 
   	else 
   	{