Work around header misdefines in modern Windows SDK when _WIN32_WINNT is less than...

diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 06aece31dc403818fb311c38c40e1f48eb544f03..c1775ea45bd51963c795b4156abddd1b7ff97ad5 100644 (file)
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -383,7 +383,7 @@ StreamServerPort(int family, char *hostName, unsigned short portNumber,
                }
 #endif
 
-#ifdef IPV6_V6ONLY
+#if defined(IPV6_V6ONLY) && defined(IPPROTO_IPV6)
                if (addr->ai_family == AF_INET6)
                {
                        if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,