Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 46054)
+++ channels/chan_sip.c	(working copy)
@@ -2254,9 +2254,9 @@
 	int error = 0;
 
 	/* init field as required */
-	if (*pass)
+	if (pass && *pass)
 		*pass = "";
-	if (*port)
+	if (port && *port)
 		*port = "";
 	name = strsep(&uri, ";");	/* remove options */
 	if (scheme) {