Ed Morris wrote me earlier today regarding an insidious bug in MT-Blacklist Updater (well, not so much an insidious bug as a logical error on my part). It all started when Ed discovered an annoying (but non-critical) bug:
I noticed that if there is an addition for a site in the changes RSS and then a deletion for that same site in the same changes file then it adds the site to the blacklist and then removes it every time the updater script is run.
When he tried to write a patch for this bug, Ed discovered a more major bug:
I realised that if a site were deleted and then re-added to the blacklist in the same changes file, the site would never get re-added locally (well it would briefly), as all deletions are carried out after additions in the script.
Notice how I like to quote him instead of paraphrasing - a sure sign of... something. I don't know what. Anyway, he fixed the entire damn thing and sent the patch over to me in the same email. All I had to do was to copy over the fixes (don't worry Ed, your PHP's great).
So, if you have an existing installation of MT-Blacklist Updater, update it to version 0.3 if you don't want it to miss any re-added blacklist entries (only those that appear at the same time in the MT-Blacklist changes feed - see Ed's explanation above).