From ba91e4b996fef320c0a703bc3021f081270ee3c1 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Mon, 11 Mar 2019 19:06:02 +0000
Subject: [PATCH] Avoid multiply defining {HIGH,LOW}_SURROGATE_{START,END}.

A user reports that under OpenWatcom these are defined in <winnls.h>,
in which case it's redundant to redefine them ourselves and provokes a
compiler diagnostic.
---
 putty.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/putty.h b/putty.h
index fc67be99..a261bf50 100644
--- a/putty.h
+++ b/putty.h
@@ -2171,10 +2171,12 @@ void request_callback_notifications(toplevel_callback_notify_fn_t notify,
 #endif
 
 /* SURROGATE PAIR */
+#ifndef HIGH_SURROGATE_START /* in some toolchains <winnls.h> defines these */
 #define HIGH_SURROGATE_START 0xd800
 #define HIGH_SURROGATE_END 0xdbff
 #define LOW_SURROGATE_START 0xdc00
 #define LOW_SURROGATE_END 0xdfff
+#endif
 
 /* These macros exist in the Windows API, so the environment may
  * provide them. If not, define them in terms of the above. */