Compatibility patch for Illumos/Solaris and possibly other platforms.
Implements getgrouplist when not provided by OS.
Without it, only the user's primary group is used in authentication!
--- 	1970-01-01 00:00:00.000000000 +0000
+++ dbus-1.6.8/dbus/getgrouplist.c	2013-02-28 13:10:51.081792722 +0000
@@ -0,0 +1,89 @@
+/*	$OpenBSD: getgrouplist.c,v 1.12 2005/08/08 08:05:34 espie Exp $ */
+/*
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* OPENBSD ORIGINAL: lib/libc/gen/getgrouplist.c */
+
+/*
+ * get credential
+ */
+#include <sys/types.h>
+#include <string.h>
+#include <unistd.h>
+#include <grp.h>
+
+int
+getgrouplist(const char *uname, gid_t agroup, gid_t *groups, int *grpcnt)
+{
+	struct group *grp;
+	int i, ngroups;
+	int ret, maxgroups;
+	int bail;
+
+	ret = 0;
+	ngroups = 0;
+	maxgroups = *grpcnt;
+
+	/*
+	 * install primary group
+	 */
+	if (ngroups >= maxgroups) {
+		*grpcnt = ngroups;
+		return (-1);
+	}
+	groups[ngroups++] = agroup;
+
+	/*
+	 * Scan the group file to find additional groups.
+	 */
+	setgrent();
+	while ((grp = getgrent())) {
+		if (grp->gr_gid == agroup)
+			continue;
+		for (bail = 0, i = 0; bail == 0 && i < ngroups; i++)
+			if (groups[i] == grp->gr_gid)
+				bail = 1;
+		if (bail)
+			continue;
+		for (i = 0; grp->gr_mem[i]; i++) {
+			if (!strcmp(grp->gr_mem[i], uname)) {
+				if (ngroups >= maxgroups) {
+					ret = -1;
+					goto out;
+				}
+				groups[ngroups++] = grp->gr_gid;
+				break;
+			}
+		}
+	}
+out:
+	endgrent();
+	*grpcnt = ngroups;
+	return (ret);
+}
--- dbus-1.6.8/dbus/dbus-sysdeps-unix.c.orig	2013-02-28 13:08:52.171215237 +0000
+++ dbus-1.6.8/dbus/dbus-sysdeps-unix.c	2013-02-28 13:13:52.224615146 +0000
@@ -21,6 +21,10 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */
+#ifndef HAVE_GETGROUPLIST
+#include "getgrouplist.c"
+#define HAVE_GETGROUPLIST
+#endif
 
 #include <config.h>