[NTG-context] Bug with rule between columns in columnset

24 Jul 2012

      Hi,

this seems like a bug in the MetaFun or column set code. Printing a
vertical rule between columns fails with

! terminal: >> NOfTextColumns-1
! Improper final value has been replaced by 0.
<to be read again> 

The code also fails, when the column set code is commented out, but
then the NOfTextColumns doesn't make sense any longer. Older betas
work perfectly.

\startuseMPgraphic{verticalline}
  for i=1 upto NOfTextColumns-1 :
    draw (rightboundary TextColumns[i]) shifted (2.5mm,0) shifted -\MPxy\textanchor;
  endfor ;
  setbounds currentpicture to OverlayBox ;
\stopuseMPgraphic

\defineoverlay [verticalline] [\useMPgraphic{verticalline}]
\setupbackgrounds [text] [background=verticalline]
\definecolumnset [example] [n=2]

\starttext
\startcolumnset [example]
  \input knuth
\stopcolumnset
\stoptext

Marco