--- a/ChangeLog	Mon Nov 11 14:19:09 2013 +0000
+++ b/ChangeLog	Wed Nov 13 07:51:40 2013 -0800
@@ -1,3 +1,9 @@
+2013-11-13  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* lib/getgroups.c (posix_getgroups, getgroups) [__APPLE__]:
+	New function and macro, to work around _DARWIN_C_SOURCE problem.
+	Reported by Jack Howarth in <http://bugs.gnu.org/14463>.
+
 2013-11-11  Pádraig Brady <P@draigBrady.com>
 
 	base64: provide a fast path for encoding well sized buffers

--- a/lib/getgroups.c	Mon Nov 11 14:19:09 2013 +0000
+++ b/lib/getgroups.c	Wed Nov 13 07:51:40 2013 -0800
@@ -43,6 +43,21 @@
 #  define GETGROUPS_ZERO_BUG 0
 # endif
 
+/* On OS X 10.6 and later, use the usual getgroups, not the one
+   supplied when _DARWIN_C_SOURCE is defined.  _DARWIN_C_SOURCE is
+   normally defined, since it means "conform to POSIX, but add
+   non-POSIX extensions even if that violates the POSIX namespace
+   rules", which is what we normally want.  But with getgroups there
+   is an inconsistency, and _DARWIN_C_SOURCE means "change getgroups()
+   so that it no longer works right".  The BUGS section of compat(5)
+   says that the behavior is dubious if you compile different sections
+   of a program with different _DARWIN_C_SOURCE settings, so fix only
+   the offending symbol.  */
+#ifdef __APPLE__
+int posix_getgroups (int, gid_t []) __asm ("_getgroups");
+# define getgroups posix_getgroups
+#endif
+
 /* On at least Ultrix 4.3 and NextStep 3.2, getgroups (0, NULL) always
    fails.  On other systems, it returns the number of supplemental
    groups for the process.  This function handles that special case