[PATCH] WIP: support XDG database directory

[David Bremner]

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

>
> this doesn't seem like a correct characterization of it, unless we're
> misunderstanding each other.
>
> it looks to me like each notmuch database *would* be coupled with
> exactly one mailstore, given this proposal.  is that right?
>
> if the library tried to open the database on its own, it would look at
> the database's stored maildir_root path.

Right, with the possibility of the user overriding the maildir, at least
at the library level. 

> or am i missing something?
>
>> That probably allows a few new kinds of user error; I'm imagining
>> runing notmuch new with mismatched database and maildir, and happily
>> deleteing all of the database documents.
>
> yikes!  still, i agree that in general i'd rather point notmuch at the
> database and have it discover everything it needs to from that; rather
> than the current approach of the split config file and database, which
> seems cumbersome and error-prone in other ways.
>
> that said, i *definitely* prefer the database identifying the mailstore
> (as you've done here) rather than the other way around.
>
> one final question: for portable databases, which live on a removable
> volume, or which are on networked-accessible storage and might be
> mounted in different places on different computers, do we have a way to
> protect them from the "whoops, mailstore is missing because you are on
> the wrong host" or ("…because you mounted the USB stick at /Media/foo
> instead of /Volumes/foo") scenario?

That's something that needs to be thought through. Essentially the same
issue I mentioned.

d