Re: Columnsetspan rendered when only when coloured?

Dear Wang Chen,

I had a quick look at your two files. I do not have a definitive 
solution, but the behaviour suggests a few possible hypotheses that 
might be worth testing step by step. I made two small tests.

The first test inserted only \strut\par immediately after 
\startcolumnset[main],
before the first \startcolumnsetspan[wide]. In that case the top span was
rendered.

The second test did not insert any material before the span, but grouped the
span contents explicitly with \start...\stop. This also made the top 
span render.

So the issue does not seem to be colour as such. The colour command probably
changes the internal structure or grouping of the contents, and this happens
to make the first span visible.

The fragile case seems to be a \startcolumnsetspan used as the very first
material immediately after \startcolumnset. A possible workaround is to 
group
the contents of the first span explicitly:

\startcolumnsetspan[wide]
\start
\samplefile{ward}
\stop
\stopcolumnsetspan

This seems cleaner than adding dummy material before the span, although both
tests suggest that the underlying issue is the same.

Then, try this MWE :

% MWE: first columnsetspan at the beginning of a columnset
%
% The fragile case seems to be a columnsetspan used as the very first
% material immediately after \startcolumnset.
%
% Adding colour around the contents makes the span appear, but the colour
% itself is probably not the real cause. A simple explicit group around
% the contents also makes the span appear.

\definecolumnset
   [main]
   [n=2,
    balance=yes,
    distance=10mm]

\definecolumnsetspan
   [wide]
   [n=2]

\starttext

% ------------------------------------------------------------
% Fragile case:
%
% In Wang Chen's original file this first span did not render.
%
% \startcolumnset[main]
%
% \startcolumnsetspan[wide]
% \samplefile{ward}
% \stopcolumnsetspan
%
% \samplefile{knuth}
% \samplefile{tufte}
% \samplefile{douglas}
%
% \stopcolumnset
% ------------------------------------------------------------

\startsubject[title={Grouped first columnsetspan}]

\startcolumnset[main]

\startcolumnsetspan[wide]
\start
\samplefile{ward}
\stop
\stopcolumnsetspan

\samplefile{knuth}
\samplefile{tufte}
\samplefile{douglas}

\stopcolumnset

\stopsubject

\stoptext

Le 11/06/2026 à 04:26, Chen Wang a écrit :
> Dear All,
>
> I am using the latest version of ConTeXt. In "main.tex", the top 
> section is not rendered. All I did was add some colouring and now the 
> top section gets rendered in "main copy.tex" in blue colour.
>
> How do I make the stuff render properly? I do not understand why the 
> top columnsetspan is not being rendered and why trying to colour it 
> makes it render.
>
> Any ConTeXt wizards please help me.
>
> Yours sincerely,
> Wang Chen
>
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