From 951b6acbbc102a5865592f671d2b410e96c5a4d3 Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@anl.gov>
Date: Mon, 3 Aug 2020 12:25:31 -0500
Subject: [PATCH] Fix Cygwin TCP_NODELAY issue from Paul Chu & Freddie

---
 documentation/RELEASE_NOTES.md               | 1 +
 modules/libcom/src/osi/os/cygwin32/osdSock.h | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/documentation/RELEASE_NOTES.md b/documentation/RELEASE_NOTES.md
index e5ff6a2f3..d54b84571 100644
--- a/documentation/RELEASE_NOTES.md
+++ b/documentation/RELEASE_NOTES.md
@@ -27,6 +27,7 @@ The following bugs/issues have fixes included in this release:
   Inaccessible CA servers on Windows
 - [github: 83](https://github.com/epics-base/epics-base/issues/83)
   osdTimeGetCurrent doesn't work for subprocess on macOS
+- Recent Cygwin build problem with a missing `TCP_NODELAY` declaration.
 
 ### Perl CA Bindings under Conda
 
diff --git a/modules/libcom/src/osi/os/cygwin32/osdSock.h b/modules/libcom/src/osi/os/cygwin32/osdSock.h
index 864744d44..1d9aa818b 100644
--- a/modules/libcom/src/osi/os/cygwin32/osdSock.h
+++ b/modules/libcom/src/osi/os/cygwin32/osdSock.h
@@ -27,6 +27,9 @@
 #include <net/if.h>
 #include <netdb.h>
 #include <unistd.h> /* close() and others */
+#ifndef TCP_NODELAY
+#  include <netinet/tcp.h>
+#endif
 
 
 typedef int                     SOCKET;