commit c3f7db262c8e2e615dae9c3db6f0385bddc48df2
Author: Miroslav Lichvar <mlichvar@redhat.com>
Date:   Fri Nov 22 18:19:41 2013 +0100

    Drop also supplementary groups when dropping privileges.
    
    Signed-off-by: Eric S. Raymond <esr@thyrsus.com>

diff --git a/gpsd.c b/gpsd.c
index c77f684..76d1850 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -2059,6 +2059,10 @@ int main(int argc, char *argv[])
 	 * of any compromises in the code.  It requires that all GPS
 	 * devices have their group read/write permissions set.
 	 */
+	if (setgroups(0, NULL) != 0)
+	    gpsd_report(context.debug, LOG_ERROR,
+			"setgroups() failed, errno %s\n",
+			strerror(errno));
 	/*@-type@*/
 #ifdef GPSD_GROUP
 	{