>From 3722df12ad7d5f13dc8bf2cf0ddc329f0541fb86 Mon Sep 17 00:00:00 2001
From: Paul Eggert <address@hidden>
Date: Mon, 29 Jun 2015 19:12:07 -0700
Subject: [PATCH] mgetgroups: fix port to strict OS X

* m4/mgetgroups.m4 (gl_MGETGROUPS):
Use more-sensitive -Werror setting if available.
---
 ChangeLog        | 11 +++++++++++
 m4/mgetgroups.m4 | 17 +++++++----------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 465bf0e..cb6ca08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2015-06-29  Paul Eggert  <address@hidden>
+
+	mgetgroups: port to strict OS X
+	* doc/glibc-functions/getgrouplist.texi (getgrouplist):
+	Document the getgrouplist problem.
+	* lib/mgetgroups.c (getgrouplist_gids) [HAVE_GETGROUPLIST]:
+	New macro.
+	(mgetgroups): Use it.
+	* m4/mgetgroups.m4 (gl_MGETGROUPS):
+	Check for OS X signature for getgrouplist.
+
 2015-06-29  Jim Meyering  <address@hidden>
 
 	linkat: fix invalid definition of LINKAT_SYMLINK_NOTSUP on OS X
diff --git a/m4/mgetgroups.m4 b/m4/mgetgroups.m4
index 5f19d4f..5747148 100644
--- a/m4/mgetgroups.m4
+++ b/m4/mgetgroups.m4
@@ -1,4 +1,4 @@
-#serial 6
+#serial 7
 dnl Copyright (C) 2007-2015 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -12,6 +12,8 @@ AC_DEFUN([gl_MGETGROUPS],
     AC_CACHE_CHECK([for getgrouplist with int signature],
       [gl_cv_getgrouplist_with_int],
       [gl_cv_getgrouplist_with_int=no
+       gl_save_c_werror_flag=$ac_c_werror_flag
+       ac_c_werror_flag=yes
        AC_COMPILE_IFELSE(
          [AC_LANG_PROGRAM(
             [[#if HAVE_GRP_H
@@ -19,11 +21,8 @@ AC_DEFUN([gl_MGETGROUPS],
               #endif
               int groups[1];
               int ngroups = 1;
-              int getgrouplist (char const *, gid_t, gid_t *, int *);
             ]],
-            [[
-              return - getgrouplist ("root", 0, groups, &ngroups);
-            ]])],
+            [[return - getgrouplist ("root", 0, groups, &ngroups);]])],
          [],
          [AC_COMPILE_IFELSE(
            [AC_LANG_PROGRAM(
@@ -32,12 +31,10 @@ AC_DEFUN([gl_MGETGROUPS],
                 #endif
                 int groups[sizeof (gid_t) == sizeof (int) ? 1 : -1];
                 int ngroups = 1;
-                int getgrouplist (char const *, int, int *, int *);
               ]],
-              [[
-                return - getgrouplist ("root", 0, groups, &ngroups);
-              ]])],
-            [gl_cv_getgrouplist_with_int=yes])])])
+              [[return - getgrouplist ("root", 0, groups, &ngroups);]])],
+            [gl_cv_getgrouplist_with_int=yes])])
+       ac_c_werror_flag=$gl_save_c_werror_flag])
     if test "$gl_cv_getgrouplist_with_int" = yes; then
       AC_DEFINE([HAVE_GETGROUPLIST_WITH_INT], 1,
         [Define to 1 if getgrouplist accepts and returns int and not gid_t.])
-- 
2.1.0