invalidAttributeSyntax error when an empty string is added

["Kazu Nisimura" <nisimura@gmail.com>]

Hi,

When I tried to add an empty string to the IA5 String attribute, slapd
returned invalidAttributeSyntax(21) error.  Is this a correct
behavior?

from RFC4517:

===
3.3.6.  Directory String

  A value of the Directory String syntax is a string of one or more
  arbitrary characters from the Universal Character Set (UCS) [UCS]...

[...]

3.3.15.  IA5 String

  A value of the IA5 String syntax is a string of zero, one, or more
  characters from International Alphabet 5 (IA5) [T.50], ...
===

It seems that zero-length IA5 String is allowed, while Directory
String have to be one or more characters.  (However, I don't
understand why zero-length Directory String is not allowed.  It is
very frustrated.)

I'm using OpenLDAP 2.3.27.

Regards,

--
Kazu Nisimura