From ba7a3204cb5b2fa2f670c9b7e1df6c16237ea115 Mon Sep 17 00:00:00 2001
From: Joel Cunningham <joel.cunningham@me.com>
Date: Wed, 9 Aug 2017 10:13:41 -0500
Subject: [PATCH] tcp: use tcp_ack_now rather than manually setting TF_ACK_NOW

---
 src/core/tcp.c                   | 2 +-
 src/core/tcp_in.c                | 2 +-
 src/include/lwip/priv/tcp_priv.h | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/core/tcp.c b/src/core/tcp.c
index d4aa3e02..b3c4c29e 100644
--- a/src/core/tcp.c
+++ b/src/core/tcp.c
@@ -1921,7 +1921,7 @@ tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb)
   if ((pcb->state != TIME_WAIT) &&
       (pcb->state != LISTEN) &&
       (pcb->flags & TF_ACK_DELAY)) {
-    pcb->flags |= TF_ACK_NOW;
+    tcp_ack_now(pcb);
     tcp_output(pcb);
   }
 
diff --git a/src/core/tcp_in.c b/src/core/tcp_in.c
index 0d5438e9..8493a31f 100644
--- a/src/core/tcp_in.c
+++ b/src/core/tcp_in.c
@@ -708,7 +708,7 @@ tcp_timewait_input(struct tcp_pcb *pcb)
 
   if ((tcplen > 0)) {
     /* Acknowledge data, FIN or out-of-window SYN */
-    pcb->flags |= TF_ACK_NOW;
+    tcp_ack_now(pcb);
     tcp_output(pcb);
   }
   return;
diff --git a/src/include/lwip/priv/tcp_priv.h b/src/include/lwip/priv/tcp_priv.h
index 7e02b604..413f7d4f 100644
--- a/src/include/lwip/priv/tcp_priv.h
+++ b/src/include/lwip/priv/tcp_priv.h
@@ -446,7 +446,7 @@ struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);
   do {                                             \
     if((pcb)->flags & TF_ACK_DELAY) {              \
       tcp_clear_flags(pcb, TF_ACK_DELAY);          \
-      (pcb)->flags |= TF_ACK_NOW;                  \
+      tcp_ack_now(pcb);                            \
     }                                              \
     else {                                         \
       (pcb)->flags |= TF_ACK_DELAY;                \