in the SELECT INTO OUTFILE clause starts with a special
character (one of n, t, r, b, 0, Z or N) and ENCLOSED BY
is empty, every occurrence of this character within a
field value is duplicated.

Duplication has been avoided.
New warning message has been added: "First character of
the FIELDS TERMINATED string is ambiguous; please use
non-optional and non-empty FIELDS ENCLOSED BY".