[NTG-context] index issues

[Henning Hraban Ramm]

> Am 06.11.2020 um 12:22 schrieb Henning Hraban Ramm <texml at fiee.net>:
> 
> (2)
> Page/column breaking is odd in that the preferred breaking point seems to be one entry too early, i.e. the last entry of one letter end up in the next column and the previous column is one line too short.
> It doesn’t change with balance=yes/no.

If one of the \index{D...} lines is commented in the following example, the last D entry goes into the second column, the columns get balanced, and the second line of the last K entry is broken to the next page.
If you uncomment that line, it looks as intended (no balancing, full left column).
What’s wrong? Can I influence this e.g. with penalties?

(Screenshots were too big...)

Hraban


\setuppapersize[A6]
\setupbodyfont[16pt]
\setupregister[index][balance=no,indicator=no]
\showframe

\starttext

%\setinjector[index][10][{\column}]
%\showinjector[index] % ERROR!
\index{Danold}
\index{Drum}
%\index{Dapper} % uncomment to test
\index{Kankra}
\index{Kookaburra}

\placeregister[index][criterium=all]
\page

\startregister[index][test]{Knuth}
  \input tufte
  \index{Donald}\index{Drom}\index{Divine}
  \page\index{Dummy}
  \input knuth
  \index{Donald}\index{Dom}\index{Dunno}
  \page
\stopregister[index][test]

\input darwin\index{Darwin}
\page

\dorecurse{5}{
\input knuth
\index{Knuth}\index{Donald}\index{Dixit}
\page\index{Knothing}
}

\stoptext