Sjur Moshagen wrote:
> 
> (*) I don't *know* that the matching file is found, I'm just assuming  
> here - how can I check that?

Turn on logging first:
http://forrest.apache.org/faq.html#logs

Then search the locationmap.log file for strings like:
"location returned for hint: pdf."
Otherwise if it is not found, it keeps looking through various
locationmaps until it runs out of places to look. There is no
"not found" type message.

-David