Instead of storing the complete message filename in the data portion
of a mail document we now store a 'direntry' term that contains the
document ID of a directory document and also the basename of the
message filename within that directory. This will allow us to easily
store multple filenames for a single message, and will also allow us
to find mail documents for files that previously existed in a
directory but that have since been deleted.
We carefully noted the fact that we had locally allocated the string
here, but then we neglected to free it. Switch to talloc instead
which makes it easier to get the behavior we want. It's simpler since
we can just call talloc_free unconditionally, without having to track
the state of whether we allocated the storage for name or not.
We never did export any interface to get at these, and when I went to
use these, I found them inadequate, (because I wanted to distinguish
address found in from: from those found in To:). Meanwhile, it was
easy enough to extract addresses with a search like:
notmuch show tag:sent | grep ^To:
so the storage of contact terms was just wasting space. Stop that.