Some PDFs render inside Firefox. I am very unhappy with that for several reasons.
Since Ubuntu ships with a good, stable and lightweight PDF-viewer, evince, I'd rather have all PDFs handled by that native viewer instead of the Firefox one.
I suspect it's because of either the mine-type, some extension, a disposition-header or some combination thereof, but some PDFs open already just fine in Evince. Others still open in the PDF.js.
How can I direct all PDFs to the native, evince, viewer?