1 files changed, 26 insertions, 9 deletions

diff --git a/gl/m4/arpa_inet_h.m4 b/gl/m4/arpa_inet_h.m4
index ea69af57..a3ba2562 100644
--- a/gl/m4/arpa_inet_h.m4
+++ b/gl/m4/arpa_inet_h.m4
@@ -1,15 +1,15 @@
-# arpa_inet_h.m4 serial 13
-dnl Copyright (C) 2006, 2008-2013 Free Software Foundation, Inc.
+# arpa_inet_h.m4 serial 17
+dnl Copyright (C) 2006, 2008-2021 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
 dnl Written by Simon Josefsson and Bruno Haible
 
-AC_DEFUN([gl_HEADER_ARPA_INET],
+AC_DEFUN_ONCE([gl_ARPA_INET_H],
 [
-  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
-  dnl once only, before all statements that occur in other macros.
+  dnl Ensure to expand the default settings once only, before all statements
+  dnl that occur in other macros.
   AC_REQUIRE([gl_ARPA_INET_H_DEFAULTS])
 
   AC_CHECK_HEADERS_ONCE([arpa/inet.h])
@@ -24,6 +24,8 @@ AC_DEFUN([gl_HEADER_ARPA_INET],
 
   AC_REQUIRE([gl_FEATURES_H])
 
+  gl_PREREQ_SYS_H_WS2TCPIP
+
   dnl Check for declarations of anything we want to poison if the
   dnl corresponding gnulib module is not in use.
   gl_WARN_ON_USE_PREPARE([[
@@ -38,17 +40,32 @@ AC_DEFUN([gl_HEADER_ARPA_INET],
     ]], [inet_ntop inet_pton])
 ])
 
+# gl_ARPA_INET_MODULE_INDICATOR([modulename])
+# sets the shell variable that indicates the presence of the given module
+# to a C preprocessor expression that will evaluate to 1.
+# This macro invocation must not occur in macros that are AC_REQUIREd.
 AC_DEFUN([gl_ARPA_INET_MODULE_INDICATOR],
 [
-  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
-  AC_REQUIRE([gl_ARPA_INET_H_DEFAULTS])
+  dnl Ensure to expand the default settings once only.
+  gl_ARPA_INET_H_REQUIRE_DEFAULTS
   gl_MODULE_INDICATOR_SET_VARIABLE([$1])
 ])
 
+# Initializes the default values for AC_SUBSTed shell variables.
+# This macro must not be AC_REQUIREd.  It must only be invoked, and only
+# outside of macros or in macros that are not AC_REQUIREd.
+AC_DEFUN([gl_ARPA_INET_H_REQUIRE_DEFAULTS],
+[
+  m4_defun(GL_MODULE_INDICATOR_PREFIX[_ARPA_INET_H_MODULE_INDICATOR_DEFAULTS], [
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_INET_NTOP])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_INET_PTON])
+  ])
+  m4_require(GL_MODULE_INDICATOR_PREFIX[_ARPA_INET_H_MODULE_INDICATOR_DEFAULTS])
+  AC_REQUIRE([gl_ARPA_INET_H_DEFAULTS])
+])
+
 AC_DEFUN([gl_ARPA_INET_H_DEFAULTS],
 [
-  GNULIB_INET_NTOP=0;     AC_SUBST([GNULIB_INET_NTOP])
-  GNULIB_INET_PTON=0;     AC_SUBST([GNULIB_INET_PTON])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_DECL_INET_NTOP=1;  AC_SUBST([HAVE_DECL_INET_NTOP])
   HAVE_DECL_INET_PTON=1;  AC_SUBST([HAVE_DECL_INET_PTON])