res_pjsip.c: Fix endpoint identifier registration name search.

If an endpoint identifier name in the endpoint_identifier_order list is a
prefix to the identifier we are registering, we could install it in the
wrong position of the list.

Assuming
endpoint_identifier_order=username,ip,anonymous

then registering the "ip_only" identifier would put the identifier in the
wrong position of the priority list.

* Fix incorrect strncmp() string prefix matching.

Change-Id: Ib8819ec4b811da8a27419fd93528c54d34f01484

res/res_pjsip.c

@@ -2573,13 +2573,13 @@ int ast_sip_register_endpoint_identifier_with_name(struct ast_sip_endpoint_ident
 
 	id_list_item = ast_calloc(1, sizeof(*id_list_item));
 	if (!id_list_item) {
-		ast_log(LOG_ERROR, "Unabled to add endpoint identifier. Out of memory.\n");
+		ast_log(LOG_ERROR, "Unable to add endpoint identifier. Out of memory.\n");
 		return -1;
 	}
 	id_list_item->identifier = identifier;
 	id_list_item->name = name;
 
-	ast_debug(1, "Register endpoint identifier %s (%p)\n", name, identifier);
+	ast_debug(1, "Register endpoint identifier %s(%p)\n", name ?: "", identifier);
 
 	if (ast_strlen_zero(name)) {
 		/* if an identifier has no name then place in front */
@@ -2602,7 +2602,8 @@ int ast_sip_register_endpoint_identifier_with_name(struct ast_sip_endpoint_ident
 	id_list_item->priority = 0;
 	while ((current = strchr(current, ','))) {
 		++id_list_item->priority;
-		if (!strncmp(prev, name, current - prev)) {
+		if (!strncmp(prev, name, current - prev)
+			&& strlen(name) == current - prev) {
 			break;
 		}
 		prev = ++current;