[NTG-context] line numbering within frame

[Thomas A. Schmitz]

Hi all,

I want line numbering within a framed environment, and I need two (at least) independent numbering systems. I hit a similar problem in 2016, and Wolfgang provided a solution (defining different numbering environment). However, this does not work within a frame. The example shows the problem:

\starttext

% This works:
\definelinenumbering[One]
   \setuplinenumbering[One]
   [style=\ss,
      distance=-2ex,
      step=2,
      location=inleft,
      start=20,
      color=darkblue]
	 \startlinenumbering[One]
	 \input knuth 
	 \stoplinenumbering
  
 \blank [line]

   \definelinenumbering[Two]
   \setuplinenumbering[Two]
   [style=\bf,
      distance=-2ex,
      step=3,
      location=inleft,
      start=4,
      color=darkred]
	 \startlinenumbering[Two]
	 \input klein
	 \stoplinenumbering

% This fails:
\framed 
   [background=color,
      backgroundcolor=gray,
      align={normal,hanging,stretch,tolerant},
      frame=off,
      loffset=6ex,
      width=\textwidth,
      foregroundstyle=\ss]
{\definelinenumbering[Three]
   \setuplinenumbering[Three]
   [style=\ss,
      distance=-2ex,
      step=2,
      location=inleft,
      start=20,
      color=darkblue]
	 \startlinenumbering[Three]
	 \input knuth 
	 \stoplinenumbering
   \blank [line]

   \definelinenumbering[Four]
   \setuplinenumbering[Four]
   [style=\bf,
      distance=-2ex,
      step=3,
      location=inleft,
      start=4,
      color=darkred]
	 \startlinenumbering[Four]
	 \input klein
	 \stoplinenumbering}

\stoptext

The framed environment fails with the error message "Missing number, treated as zero.” Does anyone know how this can be fixed?

All best

Thomas