Comment 34 for bug 25830

The "MIME specs" suggest that "Text" without a subtype should be
analyzed to determine if a multibyte set is in use. I don't know
whether there is a Unicode-aware version of file(1) aroud to peruse
the logic yet, but that is one place to start looking. Boris is also
correct that type specification should be requested when an unknown
type is encountered. So, I like this suggestion from <email address hidden>
(Martin Petricek) from duplicate bug 87301, quoted below --

When mozilla encounter unknow content-typ a dialog will appear:

[ ] use default action
[ ] use different action
   [ ] save to disk
   [ ] open with application _______

-It might be very useful to add something like-
   [ ] view as text/plain
  -- or --
   [ ] treat as [text/plain ]
 to the dialog (so i can force this to be either text/plain or text/html, etc
...)

and maybe add it also to preferences so this could be settable also as default
action
This will help to wiew content-types like netscape/proxy-autoconfig, etc ...
like plain text