Review Request: fix xkcd comic strip

[Marco Martin]

On Monday 04 February 2008, Chani wrote:
> > the only idea that comes in my mind would be a quite big change in the
> > engine, it would be a little bit more cumbersome but more flexible:
> > the provider does not work with a date but with a generic id that is a
> > qstring, that could be a date or something else like xkcd.
>
> sounds sensible to me. hardly any of the comics I read are on a daily
> schedule.

the more i think about it the more i feel that the comic dataengine is totally 
broken because of the cache, because:
if i download the latest comic and the dates/ids of the previous and next 
comic are saved i won't get the next comic, so the entry in the cache when it 
will be loaded tomorrow is wrong
or if i download the latest comic and it's let's say 11 am and a new comic is 
published at 3 pm the entry in the cache will be wrong
i was thinking about to forcefully load two times the comic if the dataengine 
doesn't have a next comic, but it's uuuuuuuugly :(

Cheers,
Marco Martin