Hi list,

In contrib/lisp/org-contacts.el:

The function `org-contacts-db-need-update-p' does two checks to
determine if the contacts cache should be updated:
1. If the variable `org-contacts-last-update' is nil.
2. If modification time of any file containing contacts is more recent than
   timestamp recorded in `org-contacts-last-update'.

There is another case where an update is required: when marker objects
contained in the contact cache `org-contacts-db' suddenly point to no
buffer. If a buffer containing contacts is killed, but underlying file
is not modified, org-contacts will not detect this, and cached markers
that pointed to the now killed buffer will become dead (have no buffer
associated with them). This seems to cause problems at least in
`org-contacts-anniversaries', which if used as diary sexp in an agenda
file, will cause "Bad sexp" errors.

I have not done any thorough analysis of `org-contacts-anniversaries'
itself, but it seems to work OK whenever the markers in
`org-contacts-db' are OK. And it looks like the markers are used in that
code.

To reproduce:
1. Load up org-contacts and do a query with "M-x org-contacts".
2. Kill at least one org-buffer containing a contact with BIRTHDAY
   property set (but do not save underlying file).
3. Make sure to use %%(org-contacts-anniversaries) in some agenda file.
4. Opening agenda should produce a "Bad sexp" error.


I've attached a patch (against git master) which I am currently using.
It will cause org-contacts to re-load if a marker is found in cache that
points to no buffer. This looked to me like the quickest approach for
fixing it without getting to know org-contacts.el better.


Regards,

Øyvind
-- 
< Øyvind Stegard
 < http://stegard.net/