From f262b3586cb40f6fdb265188456cfb0ff4e4ed2a Mon Sep 17 00:00:00 2001
From: Jeremy Tan <jtanx@outlook.com>
Date: Mon, 31 Jul 2017 21:24:38 +1000
Subject: [PATCH] configure: fix the check for IdnToUnicode

Fixes #1669
Closes #1713
---
 configure.ac | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 5104c9ecd..edcb3931f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2782,6 +2782,7 @@ if test "$want_winidn" = "yes"; then
   clean_LDFLAGS="$LDFLAGS"
   clean_LIBS="$LIBS"
   WINIDN_LIBS="-lnormaliz"
+  WINIDN_CPPFLAGS="-DWINVER=0x0600"
   #
   if test "$want_winidn_path" != "default"; then
     dnl path has been specified
@@ -2797,7 +2798,11 @@ if test "$want_winidn" = "yes"; then
   #
   AC_MSG_CHECKING([if IdnToUnicode can be linked])
   AC_LINK_IFELSE([
-    AC_LANG_FUNC_LINK_TRY([IdnToUnicode])
+    AC_LANG_PROGRAM([[
+      #include <windows.h>
+    ]],[[
+      IdnToUnicode(0, NULL, 0, NULL, 0);
+    ]])
   ],[
     AC_MSG_RESULT([yes])
     tst_links_winidn="yes"