[NTG-context] metapost background

[Johan Sandblom]

If the following is run with newtexexec, the text background on the
first page is black. On live.contextgarden.net it works ok. Another
candidate for the test suite?

\setupcolors[state=start]
\definecolor[red][r=1]
\definecolor[trwhite][s=1, t=.5, a=1]
\setupbackgrounds[state=repeat]
\defineoverlay[pagebg][\useMPgraphic{pagebg}]
\setupbackgrounds[page][background=pagebg]
\startuseMPgraphic{pagebg}
StartPage ;
fill Page withcolor \MPcolor{red} ;
fill Field[Text][Text] withcolor \MPcolor{trwhite} ;
StopPage ;
\stopuseMPgraphic

\starttext

\dorecurse{10}{\input tufte}

\stoptext

--
Johan Sandblom  N8, MRC, Karolinska sjh
t +46851776108  17176 Stockholm
m +46735521477  Sweden
"What is wanted is not the will to believe, but the
will to find out, which is the exact opposite"
- Bertrand Russell