Index: channels/chan_sip.c
===================================================================
RCS file: /var/lib/cvs/asterisk/channels/chan_sip.c,v
retrieving revision 1.4
diff -u -r1.4 chan_sip.c
--- channels/chan_sip.c	16 May 2005 17:01:37 -0000	1.4
+++ channels/chan_sip.c	19 May 2005 09:25:29 -0000
@@ -1376,7 +1376,7 @@
 
 	u = userl.users;
 	while(u) {
-		if (!strcasecmp(u->name, name)) {
+		if ((u->name != NULL) && !strcasecmp(u->name, name)) {
 			break;
 		}
 		u = u->next;