Index: configure
===================================================================
--- configure	(revision 87178)
+++ configure	(working copy)
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision.
+# From configure.in Revision: 86731 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.67 for python 3.2.
 #
@@ -9241,7 +9241,7 @@
 # checks for library functions
 for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  clock confstr ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
- gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
+ gai_strerror getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \
  getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
  initgroups kill killpg lchmod lchown lstat mbrtowc mkfifo mknod mktime \
  mremap nice pathconf pause plock poll pthread_init \
Index: configure.in
===================================================================
--- configure.in	(revision 87178)
+++ configure.in	(working copy)
@@ -2526,7 +2526,7 @@
 # checks for library functions
 AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  clock confstr ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
- gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
+ gai_strerror getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \
  getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
  initgroups kill killpg lchmod lchown lstat mbrtowc mkfifo mknod mktime \
  mremap nice pathconf pause plock poll pthread_init \
Index: Misc/NEWS
===================================================================
--- Misc/NEWS	(revision 87178)
+++ Misc/NEWS	(working copy)
@@ -11,6 +11,8 @@
 Library
 -------
 
+* Issue #9344: Add posix.getgrouplist function.
+
 * Issue #10107: Warn about unsaved files in IDLE on OSX.
 
 
Index: Misc/ACKS
===================================================================
--- Misc/ACKS	(revision 87178)
+++ Misc/ACKS	(working copy)
@@ -474,6 +474,7 @@
 Ivan Krstić
 Andrew Kuchling
 Vladimir Kushnir
+Ross Lagerwall
 Cameron Laird
 Jean-Baptiste "Jiba" Lamy
 Torsten Landschoff
Index: Lib/test/test_posix.py
===================================================================
--- Lib/test/test_posix.py	(revision 87178)
+++ Lib/test/test_posix.py	(working copy)
@@ -373,6 +373,18 @@
                 os.chdir(curdir)
                 support.rmtree(base_path)
 
+    if hasattr(posix, 'getgrouplist'):
+        def test_getgrouplist(self):
+            with os.popen('id -G') as idg:
+                groups = idg.read().strip()
+
+            if not groups:
+                raise unittest.SkipTest("need working 'id -G'")
+
+            self.assertEqual(
+                    set([int(x) for x in groups.split()]),
+                    set(posix.getgrouplist(pwd.getpwuid(os.getuid())[0], pwd.getpwuid(os.getuid())[3])))
+
     def test_getgroups(self):
         with os.popen('id -G') as idg:
             groups = idg.read().strip()
Index: Modules/posixmodule.c
===================================================================
--- Modules/posixmodule.c	(revision 87178)
+++ Modules/posixmodule.c	(working copy)
@@ -1181,7 +1181,7 @@
     HANDLE hFile;
     BY_HANDLE_FILE_INFORMATION info;
     ULONG reparse_tag = 0;
-	wchar_t *target_path;
+        wchar_t *target_path;
     const wchar_t *dot;
 
     if (depth > SYMLOOP_MAX) {
@@ -4230,7 +4230,69 @@
     return PyLong_FromPid(getpid());
 }
 
+#ifdef HAVE_GETGROUPLIST
 
+PyDoc_STRVAR(posix_getgrouplist__doc__,
+"getgrouplist(user, group) -> list of groups to which a user belongs\n\n\
+Returns a list of groups to which a user belongs.\n\n\
+    user: username to lookup\n\
+    group: base group id of the user");
+
+static PyObject *
+posix_getgrouplist(PyObject *self, PyObject *args)
+{
+#ifdef NGROUPS_MAX
+#define MAX_GROUPS NGROUPS_MAX
+#else
+    /* defined to be 16 on Solaris7, so this should be a small number */
+#define MAX_GROUPS 64
+#endif
+
+    const char *user;
+    int i, ngroups;
+    PyObject *list;
+#ifdef __APPLE__
+    int *groups, basegid;
+#else
+    gid_t *groups, basegid;
+#endif
+    ngroups = MAX_GROUPS;
+
+    if (!PyArg_ParseTuple(args, "si", &user, &basegid))
+        return NULL;
+
+#ifdef __APPLE__
+    groups = PyMem_Malloc(ngroups * sizeof (int));
+#else
+    groups = PyMem_Malloc(ngroups * sizeof (gid_t));
+#endif
+    if (groups == NULL)
+        return PyErr_NoMemory();
+
+    if (getgrouplist(user, basegid, groups, &ngroups) == -1) {
+        PyMem_Del(groups);
+        return posix_error();
+    }
+
+    list = PyList_New(ngroups);
+
+    for (i = 0; i < ngroups; i++) {
+        PyObject *o = PyLong_FromUnsignedLong((unsigned long)groups[i]);
+        if (o == NULL) {
+            Py_DECREF(list);
+            PyMem_Del(groups);
+            return NULL;
+        }
+        PyList_SET_ITEM(list, i, o);
+    }
+
+    PyMem_Del(groups);
+
+    return list;
+}
+
+#endif
+
 #ifdef HAVE_GETGROUPS
 PyDoc_STRVAR(posix_getgroups__doc__,
 "getgroups() -> list of group IDs\n\n\
@@ -7852,6 +7914,9 @@
     {"getgid",          posix_getgid, METH_NOARGS, posix_getgid__doc__},
 #endif /* HAVE_GETGID */
 #ifdef HAVE_GETGROUPS
+    {"getgrouplist",       posix_getgrouplist, METH_VARARGS, posix_getgrouplist__doc__},
+#endif
+#ifdef HAVE_GETGROUPS
     {"getgroups",       posix_getgroups, METH_NOARGS, posix_getgroups__doc__},
 #endif
     {"getpid",          posix_getpid, METH_NOARGS, posix_getpid__doc__},
Index: pyconfig.h.in
===================================================================
--- pyconfig.h.in	(revision 87178)
+++ pyconfig.h.in	(working copy)
@@ -278,6 +278,9 @@
 /* Define this if you have flockfile(), getc_unlocked(), and funlockfile() */
 #undef HAVE_GETC_UNLOCKED
 
+/* Define to 1 if you have the `getgrouplist' function. */
+#undef HAVE_GETGROUPLIST
+
 /* Define to 1 if you have the `getgroups' function. */
 #undef HAVE_GETGROUPS