Avoid core dump if isql second or third argument is omitted. diff -Naur mysql-connector-odbc-5.1.5r1144.orig/util/stringutil.c mysql-connector-odbc-5.1.5r1144/util/stringutil.c --- mysql-connector-odbc-5.1.5r1144.orig/util/stringutil.c 2008-04-14 21:03:35.000000000 -0400 +++ mysql-connector-odbc-5.1.5r1144/util/stringutil.c 2009-02-16 14:28:59.000000000 -0500 @@ -52,7 +52,7 @@ SQLINTEGER i, out_bytes; my_bool free_str= FALSE; - if (*len == SQL_NTS) + if (str && *len == SQL_NTS) *len= strlen((char *)str); if (!str || *len == 0)