Version 4 rlm_cache and LDAP cacheable_name

[Brian Julin]

TLDR: should I be using a different update block in the following for version 4?

cache ad-my-ldap-group-cache {
    driver = "rbtree"
    key = "%{User-Name}"
    ttl = 5
    add_stats = "no"
    cacheable_name = "yes"
    update {
      control.ad-my-ldap-LDAP-Group := control.ad-my-ldap-LDAP-Group
    }
}

... I ask because it seems that when loading the cache again, it copies the *same* value into multiple elements in the restored attribute, giving me [n] copies of whatever value ended up first in this list.  So either something is broken or this is a subtle behavior of := in list assignments conflicting with the special currying of the rhs in this module and I need an alternate operator.

(a few values munged to protect internal identfiers)

(6.0)            ad-my-ldap-group-cache - Found entry for "my.user.name"
(6.0)            ad-my-ldap-group-cache - Merging cache entry into request
(6.0)              ad-my-ldap-group-cache - control.ad-my-ldap-LDAP-Group := 'Group1'
(6.0)              ad-my-ldap-group-cache - control.ad-my-ldap-LDAP-Group := 'Group2'
(6.0)            ad-my-ldap-group-cache.load (updated)
(6.0)            if (!control.ad-my-ldap-LDAP-Group) {
(6.0)              | !
(6.0)                  | control.ad-my-ldap-LDAP-Group
(6.0)                  | %exists()
(6.0)                  | --> true
(6.0)              | %unary_not({true})
(6.0)              | --> false
(6.0)              ...
(6.0)            }
(6.0)            if ("%{control.ad-my-ldap-LDAP-Group[0]}/%{control.ad-my-ldap-LDAP-Group[1]}/%{control.ad-my-ldap-LDAP-Group[2]}/%{control.ad-my-ldap-LDAP-Group[n]}" == "foo") {
(6.0)                    | control.ad-my-ldap-LDAP-Group[0]
(6.0)                      | control.ad-my-ldap-LDAP-Group[0]
(6.0)                      | --> Group2
(6.0)                      | control.ad-my-ldap-LDAP-Group[1]
(6.0)                      | --> Group2
(6.0)                      | control.ad-my-ldap-LDAP-Group[2]
(6.0)                      (null)
(6.0)                      | control.ad-my-ldap-LDAP-Group[n]
(6.0)                      | --> Group2
(6.0)              | ({ngt_top/ngt_top//ngt_top} == {foo})
(6.0)              | --> false
(6.0)              ...
(6.0)            }