[NTG-context] Disappearing chapter numbers

[David Arnold]

All, We are wondering why we don't get a chapter number in our header  
in what follows. However, if we change \setupheadnumber[chapter][-1]  
\setupheadnumber[chapter][0], we do get a chapter number in the  
running head.

\setupheadnumber[chapter][0]

\setupwhitespace[medium]

\setupindenting[medium,yes]

\def\headerskip{\hskip 1em}

\def\headermarkleft{%
	\bold{\pagenumber}
	{\sc\headerskip Chapter \headnumber[chapter]\headerskip\getmarking 
[chapter][current]}}
\def\headermarkright{%
	{\sc\headnumber[section]\headerskip\getmarking[section][current] 
\headerskip}
	\bold{\pagenumber}}
	
\setupheadertexts
[\headermarkleft]
[]
[]
[\headermarkright]

\setuppagenumbering
   [state=start,
     alternative=doublesided,
     location=,
     way=bytext]

\chapter[chap:0]{Preliminaries}

\input knuth

\section{Intro to Whales}

\dorecurse{10}{\input knuth\par}

\section{Intro to Penguins}

\dorecurse{10}{\input knuth\par}

\stoptext

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