[PATCH] WIP: add all subjects to value.

[David Bremner]

Daniel Kahn Gillmor <dkg at fifthhorseman.net> writes:

>
> i think either we care about careful ordering (which strikes me as
> delicate and potentially difficult to handle, esp. when you get into the
> headers changing depending on whether you index the cleartext or not),
> or we should avoid injecting duplicates.
>

I'm not opposed to keeping the set of unique headers (although there is
a bit of a tarpit in deciding when two Subjects are the "same"). The
question I'm not sure of a good answer to is how we handle display. In
particular this patch doesn't make any effort to keep the subject
consistent with the Date and From headers. From the point of view of
displaying things, it makes sense to keep "parallel lists" in the value
slots by doing the same trick as with Subject. On the gripping hand,
sensible date search really requires one value per document.  In
principle we could make more extensive use of the document "data
area". This can store an arbitrary string, and is the recommended place
to store information needed to display the document.