The corresponding xapian document just gets more terms added to it,
but this doesn't seem to break anything. Values on the other hand get
overwritten, which is a bit annoying, but arguably it is not worse to
take the values (from, subject, date) from the last file indexed
rather than the first.
This is really pure C string parsing, and doesn't need to be mixed in
with the Xapian/C++ layer. Although not strictly necessary, it also
makes it a bit more natural to call _parse_message_id from multiple
compilation units.
The switch is easier to understand than the side effects in the if
test. It also potentially allows us more flexibility in breaking up
this function into smaller pieces, since passing private_status around
is icky.
'database.cc' is becoming a monster, and it's hard to follow what the
various static functions are used for. It turns out that about 1/3 of
this file notmuch_database_add_message and helper functions not used
by any other function. This commit isolates this code into it's own
file.
Some side effects of this refactoring:
- find_doc_ids becomes the non-static (but still private)
_notmuch_database_find_doc_ids
- a few instances of 'string' have 'std::' prepended, avoiding the
need for 'using namespace std;' in the new file.
