--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2012-05-03  Bruno Haible  <bruno@clisp.org>
+
+	getgroups: Avoid "guessing no" when cross-compiling to glibc systems.
+	* m4/getgroups.m4 (AC_FUNC_GETGROUPS): Override in autoconf < 2.70.
+	(gl_FUNC_GETGROUPS): Adapt to change of ac_cv_func_getgroups_works.
+
 2012-05-03  Bruno Haible  <bruno@clisp.org>
 
 	chown: Avoid "guessing no" when cross-compiling to glibc systems.

--- a/m4/getgroups.m4
+++ b/m4/getgroups.m4
@@ -1,4 +1,4 @@
-# serial 17
+# serial 18
 
 dnl From Jim Meyering.
 dnl A wrapper around AC_FUNC_GETGROUPS.
@@ -9,40 +9,99 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
+m4_version_prereq([2.70], [] ,[
+
+# This is taken from the following Autoconf patch:
+# http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=7fbb553727ed7e0e689a17594b58559ecf3ea6e9
+AC_DEFUN([AC_FUNC_GETGROUPS],
+[
+  AC_REQUIRE([AC_TYPE_GETGROUPS])dnl
+  AC_REQUIRE([AC_TYPE_SIZE_T])dnl
+  AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles
+  AC_CHECK_FUNC([getgroups])
+
+  # If we don't yet have getgroups, see if it's in -lbsd.
+  # This is reported to be necessary on an ITOS 3000WS running SEIUX 3.1.
+  ac_save_LIBS=$LIBS
+  if test $ac_cv_func_getgroups = no; then
+    AC_CHECK_LIB(bsd, getgroups, [GETGROUPS_LIB=-lbsd])
+  fi
+
+  # Run the program to test the functionality of the system-supplied
+  # getgroups function only if there is such a function.
+  if test $ac_cv_func_getgroups = yes; then
+    AC_CACHE_CHECK([for working getgroups], [ac_cv_func_getgroups_works],
+      [AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM(
+            [AC_INCLUDES_DEFAULT],
+            [[/* On Ultrix 4.3, getgroups (0, 0) always fails.  */
+              return getgroups (0, 0) == -1;]])
+         ],
+         [ac_cv_func_getgroups_works=yes],
+         [ac_cv_func_getgroups_works=no],
+         [case "$host_os" in # ((
+                    # Guess yes on glibc systems.
+            *-gnu*) ac_cv_func_getgroups_works="guessing yes" ;;
+                    # If we don't know, assume the worst.
+            *)      ac_cv_func_getgroups_works="guessing no" ;;
+          esac
+         ])
+      ])
+  else
+    ac_cv_func_getgroups_works=no
+  fi
+  case "$ac_cv_func_getgroups_works" in
+    *yes)
+      AC_DEFINE([HAVE_GETGROUPS], [1],
+        [Define to 1 if your system has a working `getgroups' function.])
+      ;;
+  esac
+  LIBS=$ac_save_LIBS
+])# AC_FUNC_GETGROUPS
+
+])
+
 AC_DEFUN([gl_FUNC_GETGROUPS],
 [
-  AC_REQUIRE([AC_FUNC_GETGROUPS])
   AC_REQUIRE([AC_TYPE_GETGROUPS])
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  if test "$ac_cv_func_getgroups" != yes; then
+
+  AC_FUNC_GETGROUPS
+  if test $ac_cv_func_getgroups != yes; then
     HAVE_GETGROUPS=0
-  elif test "$ac_cv_func_getgroups_works.$ac_cv_type_getgroups" != yes.gid_t
-  then
-    REPLACE_GETGROUPS=1
-    AC_DEFINE([GETGROUPS_ZERO_BUG], [1], [Define this to 1 if
-      getgroups(0,NULL) does not return the number of groups.])
   else
-    dnl Detect FreeBSD bug; POSIX requires getgroups(-1,ptr) to fail.
-    AC_CACHE_CHECK([whether getgroups handles negative values],
-      [gl_cv_func_getgroups_works],
-      [AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
-        [[int size = getgroups (0, 0);
-          gid_t *list = malloc (size * sizeof *list);
-          return getgroups (-1, list) != -1;]])],
-        [gl_cv_func_getgroups_works=yes],
-        [gl_cv_func_getgroups_works=no],
-        [case "$host_os" in
-                   # Guess yes on glibc systems.
-           *-gnu*) gl_cv_func_getgroups_works="guessing yes" ;;
-                   # If we don't know, assume the worst.
-           *)      gl_cv_func_getgroups_works="guessing no" ;;
-         esac
-        ])])
-    case "$gl_cv_func_getgroups_works" in
-      *yes) ;;
-      *) REPLACE_GETGROUPS=1 ;;
-    esac
+    if test "$ac_cv_type_getgroups" != gid_t \
+       || { case "$ac_cv_func_getgroups_works" in
+              *yes) false;;
+              *) true;;
+            esac
+          }; then
+      REPLACE_GETGROUPS=1
+      AC_DEFINE([GETGROUPS_ZERO_BUG], [1], [Define this to 1 if
+        getgroups(0,NULL) does not return the number of groups.])
+    else
+      dnl Detect FreeBSD bug; POSIX requires getgroups(-1,ptr) to fail.
+      AC_CACHE_CHECK([whether getgroups handles negative values],
+        [gl_cv_func_getgroups_works],
+        [AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
+          [[int size = getgroups (0, 0);
+            gid_t *list = malloc (size * sizeof *list);
+            return getgroups (-1, list) != -1;]])],
+          [gl_cv_func_getgroups_works=yes],
+          [gl_cv_func_getgroups_works=no],
+          [case "$host_os" in
+                     # Guess yes on glibc systems.
+             *-gnu*) gl_cv_func_getgroups_works="guessing yes" ;;
+                     # If we don't know, assume the worst.
+             *)      gl_cv_func_getgroups_works="guessing no" ;;
+           esac
+          ])])
+      case "$gl_cv_func_getgroups_works" in
+        *yes) ;;
+        *) REPLACE_GETGROUPS=1 ;;
+      esac
+    fi
   fi
   test -n "$GETGROUPS_LIB" && LIBS="$GETGROUPS_LIB $LIBS"
 ])