[Patch v2 0/3] Add test and fix exclude bug

[Austin Clements]

Quoth Mark Walters on Mar 14 at 12:26 pm:
> The test in the previous patches
> id:"1331551914-28323-1-git-send-email-markwalters1009 at gmail.com"
> triggered the bug accidentally. It accidentally set the exclude tags
> to be "=" and "deleted" rather than just "deleted". The non-existent
> "=" tag (i.e., the tag that does not occur anywhere in the Xapian
> database) triggered the bug. First we correct the tests to just set
> the "deleted" tag, then we add some tests including one with a
> deliberately non-existent tag. Finally, we modify the exclusion code
> to avoid the bug.
> 
> The modification also appears to fix a similar problem for jrollins
> that I have not yet been able to reproduce.
> 
> Since the code is now more clearly correct, cleaner and we do
> definitely avoid a Xapian bug I think these patches can be committed
> even without knowing why it fixed jrollins' bug.
> 
> Finally these apply to current master (not to the --with-excluded series).

LGTM.  It would be nice to have the broken tests marked broken in the
patch that introduces them, but it's fine.