About a year ago I wrote about a way to delete comments from tickets in Trac prior to version 0.12 (as it didn’t exist back then). Basically the method was to directly delete the comment from the database. Lately, spammers have been harassing one of my Trac installations, bypassing the spam filtering, and changing ticket properties. The old method wouldn’t revert those changes. After searching for a solution, I found a little documented option in Trac 0.12 that allows to delete comments and revert changes to tickets.
To enable it, go to the admin panel->Plugins->Trac 0.12 and enable TicketDeleter under tracopt.ticket.deleter.*. This will add a “Delete” button right next to the “Reply” and “Edit” buttons of every comment. It will also revert any changes to the ticket properties.
See #3641 and [9270] for the relevant ticket and changset in Trac’s own Trac.