Re: RFC 2596 questions

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 12:11 PM 9/23/00 +0100, David Chadwick wrote:
>> Yes, I'm reading "direct" into the 2251 statement.

So did I.  I did this also because of the specification of Attribute
Type Description in RFC 2252.  RFC2252 says that the NAME can
be an attribute description but only one SUPer type can be listed.
This implies that each attribute description has only one direct
super type (the attribute type without any options).

However, it seems that this is never used and conflicts with
common (and RFC2596) usage:  requesting "name;option" returns not
only name;option but also all subtypes (direct or indirect) of name
which have (or support) this option.  That is  "name;binary" requests
"name;binary" as well as "cn;binary", "sn;binary", etc.

>David has argued
>> that: cn;lang-en-US;lang-ja is a direct subtype of cn;lang-en-US,
>> which in turn is a direct subtype of cn. Does this also mean that it's
>> also a subtype of cn;lang-ja, 
>
>Yes, I would say so. The new dual language subtype is a subtype 
>of both single language subtypes. The order does not matter. We 
>have
>
>               supertype
>             /                  \
>subtype 1                    subtype 2
>              \                 /
>              subtype1-2

So (to clarify):

attr;a;b;c is a subtype of attr;a;b, attr;a;c, attr;b;c.
attr;a;b is a subtype of attr;a and attr;b
attr;a;c is a subtype of attr;a and attr;c
attr;b;c is a subtype of attr;b and attr;c
attr;a is a subtype of attr
attr;b is a subtype of attr
attr;c is a subtype of attr

And if:

attr is a subtype of super, then

attr;a;b;c is a subtype of super;a;b;c
...

If we had a entry containing attr and super with all combinations
of options a, b, and c; a request for super;a would return:
        super;a super;a;b super;a;b;c
        attr;a; attr;a;b attr;a;b;c

I would agree that RFC 2251 and RFC 2252 needs clarification in
this area.  I've cc'ed LDAPbis mailing list.

Kurt