Improving trac notifications

[Matthew Pickering]

I subscribe to the ghc-tickets[1] mailing list which provides updates
to all trac tickets. This is very useful, however when a ticket
description is updated the whole description is included in the email
which makes it hard to see what actually changed. The web interface
shows a nice diff[2] of the changes, I think it would be good if
emails could also include a diff rather than the current quite useless
output.

After a bit of investigation, it appears that the easiest way to
achieve this is apply a simple patch to our copy of trac. The current
format is hard coded on line 558 in this module, it seems easy to
modify this section to instead provide a diff.

http://www.edgewall.org/docs/trac-trunk/epydoc/trac.ticket.notification-pysrc.html

There is also already a module which has the diff operations
implemented which could be used.

http://www.edgewall.org/docs/trac-trunk/epydoc/trac.versioncontrol.diff-module.html

Another option would be to use something like the `AnnouncerPlugin`[3]
but that seems like much more work and would still require someone to
write a custom formatter.

Any thoughts?

Matt

[1]: https://mail.haskell.org/mailman/listinfo/ghc-tickets

[2]: https://ghc.haskell.org/trac/ghc/ticket/10873?action=diff&version=6

[3]: https://trac-hacks.org/wiki/AnnouncerPlugin