--- policykit-1-0.94/src/programs/pkexec.c.orig	2010-03-26 11:40:27.000000000 -0400
+++ policykit-1-0.94/src/programs/pkexec.c	2010-03-26 11:40:32.000000000 -0400
@@ -329,7 +329,7 @@
     }
 
   /* Look up information about the user we care about */
-  if (getpwnam_r (opt_user, &pwstruct, pwbuf, sizeof pwbuf, &pw) != 0)
+  if (getpwnam_r (opt_user, &pwstruct, pwbuf, sizeof pwbuf, &pw) != 0 || pw == NULL)
     {
       g_printerr ("Error getting information for user %s: %s\n", opt_user, g_strerror (errno));
       goto out;