[Tracker] Ideas and review for a bunch of bugs?

[TJ <tracker tjworld net>]

AS Martyn may have warned you I'm currently on a bug-fixing blitz with
the Ubuntu tracker package.

Unfortunately the Hardy 8.04 LTS (Long Term Support), Intrepid 8.10 and
forthcoming Jaunty 9.04 are all based on tracker 0.6.6. I explained to
Martyn why we can't move to trunk for Hardy or Intrepid. I'm hoping to
get Jaunty's tracker package updated to be based on trunk.

There are quite a few niggling tracker bugs affecting Ubuntu users but
no-one has been dealing with them much, until today I began trying to
solve a 100% CPU Usage issue:

https://bugs.launchpad.net/ubuntu/+source/tracker/+bug/239391

This appears to be caused by  *very* slow email deletion of Evolution
IMAP4 headers. I had Martyn piggy-back onto my tty via ssh and screen so
he could observe. Instead of several hundred deletions per second it was
about 1 every 2 seconds.

I'm wondering if it could be because there are a lot of Evolution IMAP4
accounts (15 I think) and in several of them are many high-volume
mailing-lists folders with several thousand mails. Maybe all the folder
watches are somehow interacting and slowing things down? Any suggestions
on where I ought to focus my debugging would be welcome.

A related bug is that while Evolution IMAP4 folders are being 'junk'
scanned in process_files_thread() signals are disabled (in that thread)
and therefore trackerd can ignore a SIGINT for a *long* time - 30
minutes plus in some circumstances, even thought it acknowledges the
signal being received in the main thread:

https://bugs.launchpad.net/ubuntu/+source/tracker/+bug/324381

In the process of chasing the first bug I've met several others,
reported them, and where possible created fixes:

"Incorrect parameter order for SetOption"
https://bugs.launchpad.net/tracker/+bug/324300
http://bugzilla.gnome.org/show_bug.cgi?id=570209

"Options table contains duplicate OptionKey rows"
https://bugs.launchpad.net/ubuntu/+source/tracker/+bug/324364
http://bugzilla.gnome.org/show_bug.cgi?id=570232

My proposed patch as a work-in-progress to fix existing installations
can be found attached to the Launchpad bug report. If tracker devs could
review it I'd be grateful. The key thing is to achieve a per-user,
one-time-only repair of the Options table.

'Configuration file mis-spells "Divisions" as "Dvisions" '
https://bugs.launchpad.net/ubuntu/+source/tracker/+bug/324227

I was wondering if there is a way from the trackerd process to write a
new entry to tracker.cfg to fix this one using the tracker-configuration
methods. I couldn't see an obvious way so am wondering about executing
an external "sed -i 's/Dvisions/Divisions/'
~/.config/tracker/tracker.cfg" to keep it quick and easy. 
Again, this would be one-time only, and I'd put it with the Options
table fix-up code to make the one-time detection part easy.

With these easier issues out the way I can focus on enabling signals and
handling them gracefully in process_files_thread() and figure out why
the deletion of emails is taking so long.

TJ.