special characters and \startuseMPgraphic{FunnyFrame}

[Helmut Schwertner <hschwert@gmx.de>]

Hello,

the following example does not work if the text in the 
\FrameTitle{Blockflötenspielen} contains special characters like öäßé etc.

Has someone a solution for this problem?

Thanks a lot,

Helmut


***********************************************************
\mainlanguage[de]
\language[de]
\enableregime[windows]
\setuppapersize[a4][a4]
\setupoutput[pdftex]
\pdfcompresslevel=0

\runMPgraphicstrue

\setupcolors[state=start]

\startuseMPgraphic{FunnyFrame}
  picture p; numeric w, h, o;
  p:=textext.rt(\MPstring{FunnyFrame});
  w:=OverlayWidth; h:=OverlayHeight; o:=BodyFontSize;
  p:=p shifted (2o,h-ypart center p); draw p;
  drawoptions (withpen pencircle scaled 1pt withcolor .625blue);
  draw (2o,h)--(0,h)--(0,0)--(w,0)--(w,h)--(xpart urcorner p, h) ;
  draw boundingbox p;
  setbounds currentpicture to unitsquare xyscaled (w,h);
\stopuseMPgraphic

\defineoverlay[FunnyFrame][\useMPgraphic{FunnyFrame}]

\defineframedtext[FunnyText][frame=off,background=FunnyFrame]

\def\StartFrame{\startFunnyText}
\def\StopFrame{\stopFunnyText}

\def\FrameTitle#1%
  {\setMPtext{FunnyFrame}{\hbox spread 2em {\hss\strut#1\hss}}}

\setMPtext{FunnyFrame}{}

\starttext

\FrameTitle{Blockflötenspielen}
\StartFrame
These: Blockflötenspielen macht Spaß!
\StopFrame

\stoptext