[tor-bugs] #10299 [Tor Browser]: Check whether font feature properties are problematic

[Tor Bug Tracker & Wiki]

#10299: Check whether font feature properties are problematic
-------------------------+-------------------------------------------------
     Reporter:  gk       |      Owner:
         Type:  task     |     Status:  new
     Priority:  normal   |  Milestone:
    Component:  Tor      |    Version:
  Browser                |   Keywords:  ff31-esr, tbb-fonts, tbb-
   Resolution:           |  fingerprinting, tbb-testcase, tbb-firefox-
Actual Points:           |  patch, TorBrowserTeam201409
       Points:           |  Parent ID:
-------------------------+-------------------------------------------------

Comment (by dcf):

 Replying to [comment:4 mikeperry]:
 > dcf - You're doing font things lately. Any thoughts on if these font
 variant properties make the problem any worse?

 I don't know. Certainly it doesn't make it any better. If I had to guess,
 I'd say that if two rendering engines have different ways of forming
 ligatures, for example, they are probably already distinguishable in other
 ways.

 "Support for querying and inspecting font variants was introduced." I
 might misunderstand you here. Is this something new you can do in
 JavaScript—poke around in font files to see whether they support various
 things—or do you see this as just a new source for diversity in rendering?
 Some of the font-variant stuff was already available in Firefox for a long
 time; for example I think that the [http://www.w3.org/TR/CSS2/fonts.html
 #propdef-font-variant CSS2 font-variant]
 {{{
 font-variant: small-caps;
 }}}
 let you do a special case of the [http://dev.w3.org/csswg/css-fonts
 /#propdef-font-variant-caps CSS3 font-variant-caps]:
 {{{
 font-variant-caps: small-caps;
 }}}

 My current Tor Browser is also applying ligatures in some cases already;
 for example it ligates the 'f' and 'i' in the title of
 https://en.wikipedia.org/wiki/Finite_field.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/10299#comment:6>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online