Changing fingering numerals

[Nick Payne]

If I override Fingering settings to change the style of the numerals 
used for fingering, as in the example below, I find that \finger inside 
a markup still uses the default fingering characters for the numerals.

Is this expected behaviour, or a bug? If expected behaviour, how can I 
change the fingering numerals for the trill to match those used on 
ordinary fingering?

%===================================
\version "2.17.20"

\relative f'' {
  \override Fingering.font-encoding = #'latin1
  \override Fingering.font-size = #-2
  \override Fingering.font-series = #'bold

  <g-4> <f-2> f^\trill^\markup { \finger "4242" }
}
%===================================

fingering.png
Description: PNG image