Re: LDAPprep: mapping of " " values

[Rici Lake <rici@ricilake.net>]

On 16-Nov-04, at 1:38 AM, Steven Legg wrote:

> Alternatively,
> LDAPprep can just reduce consecutive whitespace to a single space in 
> every
> case and leave the syntaxes draft to nominate the circumstances under
> which a leading or trailing space is to be removed.

This seems very sensible to me.

> A value can only match (l= *) or (l=* ) if it is all whitespace.

Not quite true. According to the insignificant space deletion rule,
a space is only a candidate for deletion if it is not followed by
a combining mark. Consequently, the sequence U+0041 U+0020 U+0020 U+0301
will be not be altered by ldapprep. (The string is LATIN CAPITAL LETTER 
A,
SPACE, SPACE, COMBINING ACUTE ACCENT.) One doesn't have to go out of 
one's
way to produce that sequence; the sequence U+0041 U+0020 U+00B4
(LATIN CAPITAL LETTER A, SPACE, ACUTE ACCENT) will be ldapprep'd into 
the
first sequence, as a result of the compatibility decomposition of U+00B4
into U+0020 U+0301. (That is, both strings render as "A ´" for anyone
with Unicode mail readers.)

Consequently, even (l= * *) could match something, but I believe that
(l= * * ) is truly impossible.