download warnings say not to download pdf files, but don't mention pdf.js
Right now our download warning text says:
Don't open documents downloaded through Tor while online
The Tor Browser will warn you before automatically opening documents that are
handled by external applications. DO NOT IGNORE THIS WARNING. You should be
very careful when downloading documents via Tor (especially DOC and PDF files)
as these documents can contain Internet resources that will be downloaded
outside of Tor by the application that opens them. This will reveal your
non-Tor IP address. If you must work with DOC and/or PDF files, we strongly
recommend either using a disconnected computer...
We should update it to say that the built-in pdf.js is ok. Otherwise users will misunderstand what we think is ok and not ok, which could undermine whether they listen to our other recommendations.