Stop Firefox from opening multiple tabs when viewing local PDFs
When I open online PDF files, everything is fine. But most of the time, I use PDF.js as the default viewer for local PDF files because all other viewers suck. In Chrome it works ok, but in Firefox, since it updated to this stupid version 57, every time I try to open a local PDF it starts opening multiple tabs, and I have to push Ctrl + W continuously until it stops. It seems even closing all of them does not stop the new ones from opening, but there is some limit.