* cygwin.din (getgrouplist): Export.

* grp.cc (get_groups): New static function to run the core functionality
	of initgroups and getgrouplist.
	(initgroups32): Call get_groups and just create supplementary group
	list in cygheap.  Rename name of first argument to "user".  Add an
	assertion to test for a NULL user name.
	(initgroups): Rename name of first argument to "user".
	(getgrouplist): New function.
	* posix.sgml (std-bsd): Add getgrouplist.
	* include/cygwin/grp.h (getgrouplist): Declare.
	* include/cygwin/version.h: Bump API minor number.

winsup/cygwin/ChangeLog

@@ -1,3 +1,17 @@
+2011-10-28  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygwin.din (getgrouplist): Export.
+	* grp.cc (get_groups): New static function to run the core functionality
+	of initgroups and getgrouplist.
+	(initgroups32): Call get_groups and just create supplementary group
+	list in cygheap.  Rename name of first argument to "user".  Add an
+	assertion to test for a NULL user name.
+	(initgroups): Rename name of first argument to "user".
+	(getgrouplist): New function.
+	* posix.sgml (std-bsd): Add getgrouplist.
+	* include/cygwin/grp.h (getgrouplist): Declare.
+	* include/cygwin/version.h: Bump API minor number.
+
 2011-10-25  Christopher Faylor  <me.cygwin2011@cgf.cx>
 
 	* child_info.h (cchildren): New struct.

winsup/cygwin/cygwin.din

@@ -716,6 +716,7 @@ getgrnam SIGFE
 _getgrnam = getgrnam SIGFE
 _getgrnam32 = getgrnam32 SIGFE
 getgrnam_r SIGFE
+getgrouplist SIGFE
 getgroups SIGFE
 _getgroups = getgroups SIGFE
 _getgroups32 = getgroups32 SIGFE

winsup/cygwin/grp.cc

@@ -13,6 +13,7 @@ Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
 details. */
 
 #include "winsup.h"
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include "cygerrno.h"
@@ -419,40 +420,86 @@ getgroups (int gidsetsize, __gid16_t *grouplist)
   return ret;
 }
 
-extern "C" int
-initgroups32 (const char *name, __gid32_t gid)
+/* Core functionality of initgroups and getgrouplist. */
+static int
+get_groups (const char *user, gid_t gid, cygsidlist &gsids)
 {
   int ret = -1;
 
   cygheap->user.deimpersonate ();
-  struct passwd *pw = internal_getpwnam (name);
+  struct passwd *pw = internal_getpwnam (user);
   struct __group32 *gr = internal_getgrgid (gid);
   cygsid usersid, grpsid;
   if (!usersid.getfrompw (pw) || !grpsid.getfromgr (gr))
     set_errno (EINVAL);
-  else
+  else if (get_server_groups (gsids, usersid, pw))
     {
-      cygsidlist tmp_gsids (cygsidlist_auto, 12);
-      if (get_server_groups (tmp_gsids, usersid, pw))
-	{
-	  tmp_gsids += grpsid;
-	  cygsidlist new_gsids (cygsidlist_alloc, tmp_gsids.count ());
-	  for (int i = 0; i < tmp_gsids.count (); i++)
-	    new_gsids.sids[i] = tmp_gsids.sids[i];
-	  new_gsids.count (tmp_gsids.count ());
-	  cygheap->user.groups.update_supp (new_gsids);
-	  ret = 0;
-	}
+      gsids += grpsid;
+      ret = 0;
     }
   cygheap->user.reimpersonate ();
-  syscall_printf ( "%d = initgroups (%s, %u)", ret, name, gid);
   return ret;
 }
 
 extern "C" int
-initgroups (const char *name, __gid16_t gid)
+initgroups32 (const char *user, __gid32_t gid)
 {
-  return initgroups32 (name, gid16togid32(gid));
+  int ret;
+
+  assert (user != NULL);
+  cygsidlist tmp_gsids (cygsidlist_auto, 12);
+  if (!(ret = get_groups (user, gid, tmp_gsids)))
+    {
+      cygsidlist new_gsids (cygsidlist_alloc, tmp_gsids.count ());
+      for (int i = 0; i < tmp_gsids.count (); i++)
+	new_gsids.sids[i] = tmp_gsids.sids[i];
+      new_gsids.count (tmp_gsids.count ());
+      cygheap->user.groups.update_supp (new_gsids);
+    }
+  syscall_printf ( "%d = initgroups (%s, %u)", ret, user, gid);
+  return ret;
+}
+
+extern "C" int
+initgroups (const char *user, __gid16_t gid)
+{
+  return initgroups32 (user, gid16togid32(gid));
+}
+
+extern "C" int
+getgrouplist (const char *user, gid_t gid, gid_t *groups, int *ngroups)
+{
+  int ret;
+
+  /* Note that it's not defined if groups or ngroups may be NULL!
+     GLibc does not check the pointers on entry and just uses them.
+     FreeBSD calls assert for ngroups and allows a NULL groups if
+     *ngroups is 0.  We follow FreeBSD's lead here, but always allow
+     a NULL groups pointer. */
+  assert (user != NULL);
+  assert (ngroups != NULL);
+
+  cygsidlist tmp_gsids (cygsidlist_auto, 12);
+  if (!(ret = get_groups (user, gid, tmp_gsids)))
+    {
+      int cnt = 0;
+      for (int i = 0; i < tmp_gsids.count (); i++)
+	{
+	  struct __group32 *gr = internal_getgrsid (tmp_gsids.sids[i]);
+	  if (gr)
+	    {
+	      if (groups && cnt < *ngroups)
+		groups[cnt] = gr->gr_gid;
+	      ++cnt;
+	    }
+	}
+      if (cnt > *ngroups)
+	ret = -1;
+      *ngroups = cnt;
+    }
+  syscall_printf ( "%d = getgrouplist (%s, %u, %p, %d)",
+		  ret, user, gid, groups, *ngroups);
+  return ret;
 }
 
 /* setgroups32: standards? */

winsup/cygwin/include/cygwin/grp.h

@@ -1,6 +1,6 @@
 /* cygwin/grp.h
 
-   Copyright 2002 Red Hat Inc.
+   Copyright 2002, 2011 Red Hat Inc.
    Written by Corinna Vinschen <corinna@vinschen.de>
 
 This file is part of Cygwin.
@@ -41,6 +41,8 @@ __gid32_t getgid32 ();
 __gid32_t getegid32 ();
 #endif
 
+extern int getgrouplist (const char *, gid_t, gid_t *, int *);
+
 #ifdef __cplusplus
 }
 #endif

winsup/cygwin/include/cygwin/version.h

@@ -422,12 +422,13 @@ details. */
       251: RTLD_NODELETE, RTLD_NOLOAD, RTLD_DEEPBIND added.
       252: CW_CVT_ENV_TO_WINENV added.
       253: Export TIOCSCTTY, tcgetsid.
+      254: Export getgrouplist.
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 253
+#define CYGWIN_VERSION_API_MINOR 254
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible

winsup/cygwin/posix.sgml

@@ -989,6 +989,7 @@ also IEEE Std 1003.1-2008 (POSIX.1-2008).</para>
     gammaf
     gammaf_r
     getdtablesize
+    getgrouplist
     getifaddrs
     getpagesize
     getpeereid