bug#33005: 27.0.50; Data loss with Gnus registry

[Michael Heerdegen]

Eric Abrahamsen <eric@ericabrahamsen.net> writes:

> (registry-collect-prune-candidates gnus-registry-db
> (registry-size gnus-registry-db) nil)

Ok, I managed to debug this.

The entry is indeed pruned.  It looks like

Key:  "<153...>"

Value: ((mark Important) (subject ...) ...)

In the `registry-collect-prune-candidates' method, the variable PRECIOUS
is bound to the list (gnorb-ids org-tags mark).

AFAIU, since PRECIOUS-P is defined as

  (lambda (entry-key) (cdr (memq (car-safe entry-key) precious)))

and the symbol mark comes last in the PRECIOUS list, the `cdr' of the
`memq' call is nil.  If I remove the `cdr' call, the entry isn't pruned
any more.  I also don't get why that `cdr' is there.  Or is my value of
PRECIOUS illegal?


Michael.