AC_REQUIRE([gl_HEADER_SYS_SOCKET])
AC_REQUIRE([AC_C_INLINE])
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+ dnl Including sys/socket.h is wrong for Windows, but Windows does not
+ dnl have sa_len so the result is correct anyway.
+ AC_CHECK_MEMBERS([struct sockaddr.sa_len], , , [#include <sys/socket.h>])
+
AC_CHECK_HEADERS_ONCE(netinet/in.h netdb.h)
AC_CHECK_DECLS([getaddrinfo, freeaddrinfo, gai_strerror, getnameinfo],,,[
/* sys/types.h is not needed according to POSIX, but the